Plaintiff v First Defendant

2 The following day, Ms Arik consulted her general practitioner about pain in her right knee, right hip, and lower back. The general practitioner arranged medical imaging investigations, which found pre-existing degenerative change in the lumbo-sacral spine, but no pathology in her right knee or hip. Ms Arik's symptoms persisted, and an MRI scan of her right hip in April 2020 reported features of low-grade trochanteric bursitis and a chronic superior labral tear. She claims to have suffered injuries to her lower back and right hip, for which she seeks compensation from the owner and manager of the Centre, Vicinity Centres PM Pty Ltd.

3 Under Pt VBA of the Wrongs Act 1958 (Vic), Ms Arik can only recover damages for non-economic loss if she suffered a 'significant injury' as a result of her fall.[1] This necessitates a medical assessment that 'the degree of impairment of the whole person resulting from the injury' satisfies the 'threshold level'.[2]

4 On 1 April 2021, Dr Graeme Doig, an orthopaedic surgeon and independent medical assessor, provided a certificate of assessment for Ms Arik, in which he certified that he was satisfied that the degree of impairment resulting from her injury satisfied the threshold level. Dr Doig described the injuries as soft tissue injuries to the lower back and right hip.

5 In response to this certificate, on 26 May 2021, Vicinity referred a medical question to a Medical Panel for determination.[3] The question was whether the degree of impairment resulting from the physical injury alleged in Ms Arik's claim satisfied the threshold level. Vicinity provided the Panel with information including Dr Doig's certificate of assessment and his medico-legal report of 14 April 2021, and asked the Panel to request records from Ms Arik's treating general practitioners.

6 A Medical Panel was convened to consider the referral, comprising Associate Professor David Ernest, general physician, and Mr Keith McCullough, orthopaedic surgeon. The Panel examined Ms Arik on 28 June 2021, with the assistance of a Turkish language interpreter.

7 The Panel provided its certificate of determination and a written statement of reasons on 1 July 2021. The effect of the Panel's determination is that Ms Arik did not suffer a 'significant injury' because of the fall on 1 December 2019, and so cannot recover damages for non-economic loss in respect of her injuries.

8 In this proceeding, Ms Arik seeks judicial review of the Panel's determination. She contends that it was affected by jurisdictional error, because the Panel did not assess her degree of impairment in accordance with the American Medical Association's Guides to the Evaluation of Permanent Impairment (Fourth Edition) (Guides), as required by s 28LH of the Wrongs Act. She also argues that the Panel failed to take into account a mandatory relevant consideration, namely a direction in Section 3.2 of the Guides about the method for assessing impairment of a lower extremity part. Ms Arik seeks an order in the nature of certiorari quashing the Panel's determination, and an order in the nature of mandamus remitting the referred medical question to the Convenor of Medical Panels to be reconsidered in accordance with law.

9 For the reasons that follow, I have concluded that the Panel's determination was affected by jurisdictional error, because it did not assess Ms Arik's degree of impairment in accordance with the Guides. I will make orders quashing the Panel's determination, and remitting the referred medical question to the Convenor for reconsideration in accordance with law.

10 The Panel's certificate of determination was given pursuant to s 28LWE of the Wrongs Act, on 1 July 2021. It set out the Panel's answer to the question that had been referred to it:

Question: Does the degree of impairment resulting from the physical injury to the claimant alleged in the claim satisfy the threshold level?

Answer: The Panel determined that the degree of whole person impairment resulting from the physical injury to the claimant alleged in the claim does not satisfy the threshold level.

11 The Panel's reasons for the determination noted that Ms Arik was examined by both members of the Panel on 28 June 2021. The Panel said that it formed its opinion with regard to the documents and information referred to it in 'Enclosures A and B', the history provided by Ms Arik, and the examination findings elicited by the Panel at the examination. Enclosure A listed the documents provided by Vicinity's solicitors with the referral, and Enclosure B listed further information obtained by the Panel, including records obtained from her general practitioners.

12 The Panel recorded that Ms Arik told it that in December 2019 she slipped on water while at the Centre and fell on her right knee. It noted her claim that the physical injuries she suffered as a result of the incident are 'soft tissue injuries to the lower back with aggravation of pre-existing degeneration of the lumbar spine; injuries to the right hip with trochanteric bursitis and a labral tear'.

13 The history recorded by the Panel included Ms Arik's description of the incident, the subsequent medical treatment and investigations, an outline of her clinical course, and her current symptoms. The Panel then recorded its findings on physical examination:

Examination

On physical examination the Panel noted the claimant walked with a normal gait, and she was able to stand alternately on each leg with support. Trendelenburg's sign was absent when single leg standing on each side. The leg lengths were equal and she stood with a normal lumbar lordosis.

There was local tenderness to palpation over the lower lumbar spine and over the right sacroiliac joint. There was no evidence of lumbar spine muscle spasm or guarding. There was a symmetrical restriction in the range of all movements of the lumbosacral spine, limited at end-range due to discomfort.

Neurological examination revealed normal tone and power in the legs within the limits of testing, symmetrical lower limb reflexes and preserved light tough sensation over the legs. The Panel considered that there was no clinical evidence of any spine-related radiculopathy or peripheral nerve disorder evident on examination.

Examination of the right hip revealed a mild-moderate restriction in the active range of movements and there was no fixed flexion deformity. There was restriction in the range of movements of right hip flexion (60 degrees), abduction (20 degrees), adduction (10 degrees) external rotation (15 degrees) and internal rotation (20 degrees). There was no significant right thigh muscle wasting present on formal measurement.

14 After noting the reports of the medical imaging investigations in the referral material, the Panel considered that it did not require any further imaging or other investigations. It then provided its diagnosis:

The Panel considers that the claimant likely suffered soft tissue injuries involving her lumbar spine and right hip at the time of the incident. The Panel accepts that the claimant continues to suffer from persisting lower back and right hip symptoms. The Panel considers that the imaging findings of L5/S1 facet joint arthropathy (CT scan, 10 December 2019) and right hip trochanteric bursitis and a labral tear (MRI scan, 1 April 2020) are constitutional in nature and origin and have not been affected by the soft tissue injuries experienced at the time of the incident.

...

The Panel, on the basis of the claimant's history, the materials provided with the referral and its examination findings concluded that the claimant is suffering from persisting lower back symptoms and right hip pain and movement restriction following a soft tissue injury.

The Panel considers this condition is "referable to the fault of another person whose conduct the complainant complains of."

The Panel considers the claimant's medical condition has stabilised.

15 The critical section of the Panel's reasons concerns its impairment assessment:

Impairment assessment

The Panel conducted an impairment assessment in accordance with the American Medical Association Guides to the Evaluation of Permanent Impairment (Fourth Edition) ("the Guides") as required by Section 28LH of the Wrongs Act 1958 ("the Act"). The Panel considered no further information was required from the claimant's treating practitioners to carry out the assessment.

Lumbar spine

The Panel carried out an impairment assessment of the lumbosacral spine in accordance with the Specific Procedures and Directions in Section 3.3f on page 101 of the Guides.

The Panel assessed the appropriate impairment category and whole person impairment for the lumbosacral spine in accordance with Tables 70 and 72 of Chapter Three.

As the impairment attributable to the lumbosacral spine could be assessed in accordance with the Diagnosis Related Estimates (DRE) Model, the use of the Range of Motion Model is not appropriate.

Right hip

The Panel also assessed impairment of the right hip in accordance with Section 3.2 of Chapter Three. Active joint ranges of movement were measured using a goniometer in accordance with the instructions in the Guides.

The Panel considered the most appropriate method to assess impairment of the right hip was by range of motion in accordance with Section 3.2e.

As the process of rating range of motion deficits of the lower extremity is based on a classification of mild, moderate or severe, the Panel is of the opinion that the direction of motion of the right hip that provides the highest rating is used to determine impairment for that joint.

The Panel assessed the appropriate whole person impairment due to restriction of movement of the right hip in accordance with Table 40 of Chapter Three.

16 In relation to apportionment, the Panel accepted that Ms Arik had never suffered from any previous back or right hip injury. On that basis it concluded that there was no verifiable evidence of any pre-existing or unrelated condition that had to be disregarded in accordance with s 28LL(3) of the Wrongs Act.

17 The Panel then set out its analysis and conclusions in relation to the assessment of impairment:

The Panel combined the whole person impairments using the formula A + B (1 - A) as prescribed on page 322 of the Guides.

The Panel concluded that:

• the degree of whole person impairment resulting from the lumbosacral spinal injury to the claimant alleged in the claim is permanent, but is not 5% or more and therefore does not satisfy the threshold level prescribed by Section 28LB of the Act as amended; and
• after combining the whole person impairments attributable to all of the physical injuries to the claimant alleged in the claim according to the method prescribed on page 322 of the Guides, the degree of whole person impairment resulting from the spinal injury and/or the physical injuries to the claimant alleged in the claim is permanent, but is not more than 5%.

18 The Panel said it had assessed impairment arising from Ms Arik's claimed physical injuries in accordance with the appropriate chapters in the Guides, and considered that further explanation or detailed reasons of the basis on which it had calculated impairment was prohibited by s 28LZG(4) of the Wrongs Act.

19 Finally, the Panel noted Dr Doig's medico-legal report and certificate of assessment, and commented on the differences in their respective conclusions:

At the time of his assessment, Dr Doig diagnosed soft tissue injuries to the claimant's back and right hip. He reported on the clinical findings of asymmetrical loss of lumbar spine range of motion with guarding, and normal right hip movements except for flexion.

The Panel's examination on 28 June 2021 as reported above differed in that it identified a symmetrically restricted range of lower back movements without dysmetria, guarding or radiculopathy, and a restriction in the range of all right hip movements.

20 Part VBA of the Wrongs Act applies to claims for the recovery of damages for non‑economic loss, with exceptions as provided in s 28LC. Section 28LE provides that a person is not entitled to recover damages for non-economic loss in any proceeding in a court in respect of an injury to a person caused by the fault of another person unless the person injured has suffered significant injury.

21 The term 'significant injury' is defined in s 28LF. Section 28LF(1) provides that an injury to a person (other than a psychiatric injury) is a significant injury if, relevantly:

(a) the degree of impairment of the whole person resulting from the injury has been assessed by an approved medical practitioner in accordance with this Part as satisfying the threshold level, unless a Medical Panel has made a determination as to the threshold level under Division 5; or

(aa) a certificate of assessment has been issued under section 28LNA in respect of the injury, unless a Medical Panel has made a determination as to the threshold level under Division 5; or

(b) a Medical Panel has determined under Division 5 that the degree of impairment of the whole person resulting from the injury satisfies the threshold level;

22 The 'threshold level' is defined in s 28LB to mean, in the case of injury (other than psychiatric or spinal injury), impairment of more than 5% and, in the case of spinal injury, impairment of 5% or more.

23 The assessment of degree of impairment must be made by an approved medical practitioner.[4] Section 28LH provides:

How is the degree of impairment to be assessed?

(1) Subject to this Division, an approved medical practitioner must make an assessment of degree of impairment under this Part -

(a) in accordance with -

(i) the A.M.A. Guides; or

(ii) the methods prescribed for the purposes of this Part; and

(b) in accordance with operational guidelines (if any) as to the use of those Guides or methods issued by the Minister.

(2) Nothing in subsection (1) prevents an assessment being made in respect of a degree of impairment of a person even if not all of the injuries to the person have stabilised.

24 Medical Panels are constituted under s 537 of the Workplace Injury Rehabilitation and Compensation Act 2013 (Vic) (WIRC Act) as necessary for the purposes of the WIRC Act, the Accident Compensation Act 1985 (Vic) (AC Act), and Pt VBA of the Wrongs Act. From a list of medical practitioners appointed by the Governor in Council, a Convenor is appointed,[5] who may convene and constitute a Medical Panel appropriate to each particular case.[6]

25 The function of a Medical Panel is neither arbitral nor adjudicative; it is 'to form and to give its own opinion on the medical question referred for its opinion'.[7] Under Pt VBA of the Wrongs Act, the 'medical question' is invariably 'a question as to whether the degree of impairment resulting from injury to the claimant alleged in the claim satisfies the threshold level'.[8]

26 A determination by the Medical Panel that the degree of impairment resulting from an injury satisfies the threshold level must be accepted by a court in any proceeding on the claim as a determination of significant injury for the purposes of Pt VBA of the Wrongs Act.[9] Conversely, a determination that the degree of impairment does not satisfy the threshold level must be accepted as a determination that the injury is not a significant injury.[10]

27 The principles relevant to the interpretation and application of the Guides by a Panel asked to determine a claimant's degree of impairment for the purposes of Pt VBA of the Wrongs Act were summarised by Kyrou J in Saddington v Kotzman:[11]

The interpretation of the Guides is a question of law. The determination of a degree of impairment is a question of fact.

It has been said that to the extent that an Act requires determinations of impairment to be made in accordance with the Guides, the Guides has the force of law and is a legislative document.

However, the Guides is, as its title suggests, a guide. It was written by expert medical practitioners and not by statutory draftspeople, and should not be overlaid with legalistic - or a lawyer's precise - interpretation. It is of paramount importance to be faithful to the Guides' plain words. The Guides should not be interpreted as if it were a statute.

The use of the Guides is designed to promote precision, certainty and consistency. Its purpose is to make as objective as possible the process of estimating impairment by reference to sufficient medical and non-medical information to justify the estimate.

If there is any inconsistency between the Act and the Guides, the Act will prevail. If there is any inconsistency between the text in the Guides and an example which seeks to illustrate what is said in the text, the text will prevail.

The meaning of the phrase 'in accordance with' depends on the context. It is generally taken to mean 'in conformity with', although in some contexts, strict compliance is not required.

In order for a medical panel to assess impairment 'in accordance with' the Guides as required by ss 28LZG(1) and 28LH(1)(a) of the Act, it must act in conformity with the Guides. This means that it must apply the methodologies, processes and criteria set out in the Guides for the relevant condition, body part or system and adhere to any minimum or maximum values set out in the Guides for that condition, body part or system. Where the Guides contains a table that is applicable to a condition, body part or system, an assessment based on that table will not be in accordance with the Guides unless the categories, descriptions, criteria, ranges, adjustments and other elements of the table that are relevant to the condition, body part or system are adhered to and complied with.

Once a particular methodology or table is selected, its requirements, including any limitations, must be applied in the manner set out by the Guides even if the outcome may appear sub-optimal. This is so because the role conferred by the Act on a medical panel is not to arrive at a correct or fair assessment, but rather to arrive at an assessment that is the product of the application of the Guides.

28 These principles have been adopted and applied in other decisions of this Court.[12]

29 A plaintiff who contends that a Medical Panel fell into jurisdictional error by failing to conduct an assessment 'in accordance with' the Guides must demonstrate that the Panel 'departed from the methodology laid down by the AMA Guides to such an extent that it can be properly said of the assessment that it was not "in accordance with" the Guides'.[13]

30 The first edition of the Guides was published in 1971. The current edition is the sixth edition, which was first published in 2008 and has been updated several times since then. Part VBA of the Wrongs Act applies the fourth edition of the Guides, which was published in 1993.

31 The Glossary to the Guides defines a number of terms used in impairment assessment, including 'impairment' itself:

1. Impairment: Impairment is the loss, loss of use, or derangement of any body part, system, or function.

32 Chapter 1 is headed 'Impairment Evaluation', and provides an outline of the framework and method of analysis provided by the Guides for evaluating and communicating information about the impairment of any part of the human body. The outline commences with Section 1.1 - Impairment, Disability, Handicap, which elaborates on the definition of 'impairment' for the purposes of the Guides:

1.1 Impairment, Disability, Handicap

Impairment is defined in the Guides as an alteration of an individual's health status. Impairment, according to the Guides, is assessed by medical means and is a medical issue. An impairment is a deviation from normal in a body part or organ system and its functioning. The Guides defines "permanent impairment" as one that has become static or stabilized during a period of time sufficient to allow optimal tissue repair, and one that is unlikely to change in spite of further medical or surgical therapy.

The Guides definition of an impairment closely parallels that of the World Health Organization (WHO), which has defined an impairment as "any loss or abnormality of psychological, physiological, or anatomical structure or function."

In the Guides, impairments are defined as conditions that interfere with an individual's "activities of daily living," some of which are listed in the Glossary (p. 315). Activities of daily living include, but are not limited to, self-care and personal hygiene; eating and preparing food; communication, speaking, and writing; maintaining one's posture, standing, and sitting; caring for the home and personal finances; walking, traveling, and moving about; recreational and social activities; and work activities.

An impairment percentage derived by means of the Guides is intended, among other purposes, to represent an informed estimate of the degree to which an individual's capacity to carry out daily activities has been diminished.

The Guides recognizes that "normal" is not a fine point or an absolute in terms of physical and mental functioning and good health. More often, normality is a range or a zone, as with vision and hearing. The normal can vary with age, sex, and other factors. For example, the physical abilities and the visual capabilities of a 21-year-old almost certainly will differ from those of a 75-year-old person. An interpretation of normal that is too strict can result in an overestimation or underestimation of impairment. What is normal must be determined by sufficient studies of representative populations carried out with valid methods.

33 Chapter 3 of the Guides is headed 'The Musculoskeletal System', which is divided into four sections: the upper extremity, the lower extremity, the spine, and the pelvis. Relevant here is the lower extremity, which is further divided into six sections:

The lower extremity has six sections: the foot, the hindfoot, the ankle, the leg, the knee, and the hip. The foot has five digits: the great toe and the second, third, fourth and fifth toes. The great toe has two joints: the interphalangeal (IP) and the metatarsophalangeal (MTP) joints. The second, third, fourth and fifth toes all have three joints: the DIP, PIP, and MTP joints.

34 Section 3.2 - The Lower Extremity, was the section used by the Panel to assess Ms Arik's right hip impairment. Several different methods are provided for evaluating impairment of the lower extremity, with the following explanation of how those methods should be used:

3.2 The Lower Extremity

Anatomic, diagnostic, and functional methods are used in evaluating permanent impairments of the lower extremity. While some impairments may be evaluated appropriately by determining the range of motion of the extremity, others are better evaluated by the use of diagnostic categories or according to test criteria.

In general, only one evaluation method should be used to evaluate a specific impairment. In some instances, however, as with the example on p. 77, a combination of two or three methods may be required.

This section includes information on using some of the simpler, more reproducible methods of and tests for assessing function. It also includes examples illustrating how the physician selects the best approach to evaluate an impairment. Selecting the optimal approach or combining several methods requires judgment and experience. Also needed is careful testing that produces accurate and consistent results.

To make this section easier to use, the tables of this section show the impairment percents of the whole person, the lower extremity, and the specific part together. The whole-person impairments are not in parentheses, the lower-limb impairment percents are in parentheses ( ), and the specific part impairments are in brackets [ ]. Multiplying a lower extremity impairment percent by 0.4 yields the whole-person impairment percent. Multiplying the specific-part impairment percent by 0.7 yields the lower extremity impairment percent.

If the patient has several impairments of the same lower extremity part, such as the leg, or impairments of different parts, such as the ankle and a toe, the whole-person estimates for the impairments are combined (Combined Values Chart, p. 322). If both extremities are impaired, the impairment of each should be evaluated and expressed in terms of the whole person, and the two percents should be combined (Combined Values Chart, p. 322).

The figures for this section, which illustrate how to measure ranges of motion, the distribution of motor and sensory nerves, and the tibia-os calcis angle, are at the end of the section (pp. 90 through 93).

35 The evaluation method used by the Panel was 3.2e - Range of motion:

Evaluating permanent impairment of the lower extremity according to its range of motion is a suitable method. Principles similar to those for manual muscle testing apply because the patient's pain or motivation may affect the results. If it is clear to the evaluator that a restricted range of motion has an organic basis, multiple evaluations are unnecessary. If, however, multiple evaluations exist, inconsistency of a grade between the findings of two observers, or on separate occasions by the same observer, makes the results invalid. The arcs listed are examples of mild, moderate, and severe impairments and are to be used as guides.

36 Section 3.2e contains tables for the several lower extremity parts. Table 40 is relevant in this case.

*An abduction contracture of greater than 20% is a 15% whole-person impairment.

...

37 The other tables in Section 3.2e are Table 41 - Knee Impairments, Table 42 - Ankle Motion Impairments, Table 43 - Hindfoot Impairments, Table 44 - Ankle or Hindfoot Deformity Impairments, and Table 45 - Toe Impairments.

38 On 10 October 2022, Vicinity issued a subpoena for production to the Prothonotary addressed to the Proper Officer of AMA Victoria. AMA Victoria is the trading name of Australian Medical Association (Victoria) Limited, which is a professional association for Victorian doctors. It is not related to the American Medical Association, the publisher of the Guides.

All documents relating to, or used during, the training provided to medical practitioners in relation to the AMA Guides to the Evaluation of Permanent impairment 4th Edition, including but not limited to training materials, handbooks, textbooks, booklets, guides, hand-outs, factsheets and PowerPoint presentations from 1 January 2019 to date and which relate to:

(a) the assessment of impairment of the lower extremity; and

(b) the assessment of impairment using the Range of Motion method.

40 Ms Arik's solicitors wrote to the Prothonotary on 13 October 2022, objecting to the inspection of the documents identified in the subpoena.[14] The ground of objection stated in the letter was that the subpoena was a fishing exercise with no legitimate forensic purpose.

41 At the start of the trial I heard argument about the objection, and then set aside the subpoena on the basis that it had no legitimate forensic purpose. What follows are my reasons for that ruling.

42 Vicinity relied on the requirement of Pt VBA that an assessment of impairment be made by an 'approved medical practitioner' - that is, a medical practitioner who has successfully completed a training course approved by the Minister under s 91(1)(b) of the AC Act or s 54(1)(b) of the WIRC Act.[15] It referred to Gillat v Transport Accident Commission,[16] in which it was held that a doctor who had only completed part of the training course was not an approved medical practitioner. It also referred to Taylor v Mountain Pine Furniture Pty Ltd,[17] in which there was a question (not decided) about whether a medical panel had erroneously relied on material from the training course that was inconsistent with the Guides.

43 Vicinity also relied on the fact that the training course delivered by AMA Victoria had been approved by the Minister under the AC Act and the WIRC Act. The Minister's approval was said to give some insight into how Parliament intended the Guides to be used and applied by medical practitioners. It relied on the Court of Appeal's reasoning in Georgopoulos v Silaforts Painting Pty Ltd[18] to argue that evidence of past or persistent practice can assist in the interpretation of legislation. More generally, Vicinity referred me to O'Connell v Munoz Pty Ltd,[19] regarding the relationship between the Guides and the Wrongs Act. In that case, O'Meara J held that the definition of 'impairment' in the Guides was not a substitute for the statutory definition of 'impairment'.[20]

44 Ms Arik started with the proposition that it was for Vicinity to identify a legitimate forensic purpose for the production of the documents identified in the subpoena, in the sense that there was a reasonable possibility that the documents would be of relevance to or of assistance to its case.[21] She submitted that all of the authorities referred to by Vicinity were distinguishable from this case, in which there was no issue about the training undertaken by the members of the Panel, and nor was there any question about the interpretation of the Wrongs Act.

45 In this case, there is no issue about the proper interpretation of the relevant provisions of the Wrongs Act. Both parties accepted and relied on Kyrou J's statement of the relevant principles in Saddington v Kotzman, set out at [27] above. The question for determination is whether the Panel assessed Ms Arik's impairment 'in accordance with' the Guides. That requires interpretation of the words used by the authors of the Guides, as distinct from the words used by the legislature in adopting the Guides as the method assessing impairment under Pt VBA of the Wrongs Act. The proper interpretation of the Guides is a question of law.

46 The interpretation of a statutory provision may be assisted by reference to extrinsic materials that are relevant to the context and purpose of the provision.[22] For example, evidence of the previous state of the law can help by identifying the mischief to which the provision was directed. Other examples are evidence of legislative history, law reform documents, and parliamentary debates, in particular the second reading speech for the statute. What these examples have in common is that they provide some insight into the context in which the provision was enacted and, perhaps, what the legislature was trying to achieve by the provision.

47 While the Guides is not to be interpreted as if it were a statute, I accept that there may be occasions where extrinsic materials may help with its interpretation. In this case, Ms Arik sought to rely on earlier and later editions of the Guides, to support her contended meaning of the relevant parts of Ch 3 of the fourth edition. Vicinity argued that regard should not be had to any other edition of the Guides. There is previous Victorian authority on that question, which I will consider below.[23] Aside from that authority, there is a logical connection between successive editions of the Guides, and it is at least on the cards that the interpretation of Ch 3 of the fourth edition might be informed by the evolution of the equivalent chapter over time.

48 There is, however, no logical connection between training course materials used by AMA Victoria since 1 January 2019 and the fourth edition of the Guides published by the American Medical Association in 1993. The training course that is now delivered by the AMA Victoria is separated by both time and geography from the formulation of the fourth edition of the Guides, and can give no insight into its context or purpose.

49 The connection is not made by the ministerial approval of the training course, under the AC Act and the WIRC Act. That was an executive act of a Victorian Government Minister, done to implement Parliament's adoption of the Guides as the standard for impairment assessment under Victorian legislation including Pt VBA of the Wrongs Act.

50 None of the authorities referred to by Vicinity supported the proposition that the content of the training scheme might inform the interpretation of the Guides.

51 For those reasons, I concluded that the documents identified in the subpoena could have no relevance to the proper interpretation of Ch 3 of the Guides, and that there was no legitimate forensic purpose in seeking their production.

Preliminary matter - Admissibility of evidence not before the Panel

52 Both Ms Arik and Vicinity sought to rely on opinions expressed by medical practitioners that were not before the Panel. Ms Arik sought to tender an affidavit of her solicitor exhibiting correspondence with Associate Professor Anthony Buzzard regarding the 'normal' range of motion of the ankle joint. For its part, Vicinity sought to rely on a report of Mr Michael Dooley, in which he responded to questions about the training he had received in conducting impairment assessments in accordance with the Guides and provided his opinion as to the correct method for assessing the degree of range of motion impairment of a lower extremity body part.

53 I ruled this material inadmissible, and again said that I would provide my reasons for that ruling in this judgment.

54 In a judicial review proceeding such as this one, the lawfulness of the decision under review is ordinarily determined by reference only to the material that was before the decision-maker when the decision was made.[24] In the case of a medical panel, the only material that is usually admissible is the material on which the panel formed its opinion.[25] Evidence that was not before the decision-maker - or, in this instance, the Panel - is generally inadmissible. Some recognised exceptions to this general rule were identified by the Court of Appeal in Mackenzie v Head, Transport for Victoria:[26]

(1) Evidence that constitutes an admission by the decision-maker.

(2) Evidence that falls within the Prasad principle, that is, evidence that is capable of showing that the decision-maker failed to make an obvious inquiry about a critical fact, the existence of which is easily ascertained, and the failure renders the decision legally unreasonable or constitutes a constructive failure to exercise jurisdiction.

(3) Evidence that is capable of showing that the decision-maker made an error as to a jurisdictional fact and therefore did not have jurisdiction to make the decision.

(4) Evidence that is capable of showing that the decision-maker made an error as to a non-jurisdictional fact of such a nature that he or she thereby constructively failed to exercise jurisdiction.

(5) Expert evidence that is capable of showing that there was no intelligible foundation for the decision.

55 A further exception emerges from an earlier Court of Appeal decision, in Victorian WorkCover Authority v Elsdon,[27] which involved judicial review of an opinion of a medical panel. The trial judge had refused to receive additional medical reports about the meaning of the word 'fractures' in the Guides, ruling that the reports were irrelevant. By a majority, the Court of Appeal upheld that ruling, on the basis that the word 'fractures' does not bear a technical or specialist meaning.[28] However, the majority accepted that, where relevant, a reviewing court 'may receive expert evidence in determining whether there is any specialised meaning of words or phrases and, if so, what that meaning is'.[29]

56 Neither party contended for the existence of any other exception to the general rule. Both parties submitted that the further opinion evidence they sought to adduce fell within one or more of the existing exceptions.

57 Ms Arik's solicitors asked Associate Professor Buzzard to provide an 'on the papers' report on the following question:

When measured with a goniometer, what is considered to be the 'normal' range of motion (i.e. from 0 degrees to X degrees) of the ankle in:

a. flexion (plantar flexion); and

b. extension (dorsiflexion)?

Insofar as there is some variance in what is considered to be the 'normal' range of motion of each these directions of movement, please set out that variance.

Please provide your references, citations or sources.

58 Associate Professor Buzzard provided a short report in response, to the effect that the normal range of movement of the ankle joint is 'taken into account using Table 42 (Ankle motion impairment)' in the Guides - in other words, 'anything greater than 20° of plantar flexion is considered to be normal and anything greater than 10° of dorsiflexion (extension) is considered to be normal.' This response was clarified by some subsequent correspondence, in which Associate Professor Buzzard confirmed that the figures in the Guides for a 'normal' range of dorsi/plantar flexion accorded with his own experience in a clinical setting and as an independent examiner.

59 Ms Arik sought to rely on this evidence in support of a submission about the proper method for assessing range of motion impairment of the lower extremity, based on the example given in Section 3.2e of the Guides.[30] She submitted that it was admissible under the exception identified in Elsdon, as evidence of the meaning of a specialised technical term or phrase. The phrase in question was 'she had lost half of the ankle flexion and extension motion'.

60 In addition, Ms Arik said that the report was admissible as evidence of legal unreasonableness. She submitted that her second ground of review, failure to take into account a mandatory relevant consideration, was a species of legal unreasonableness.[31]

61 In case I was not attracted to that characterisation, Ms Arik also sought leave to amend her originating motion to add a third ground of review, 'and/or acted in a legally unreasonable way having regard to the failures in (a) and (b)'. I refused leave to amend. My reasons for that ruling are at [71] to [75] below.

62 I did not consider that Associate Professor Buzzard's evidence was admissible under either of the exceptions relied upon by Ms Arik.

63 In relation to the Elsdon exception, the evidence did not touch on whether the phrase 'she had lost half of the ankle flexion and extension motion' had a specialised or technical meaning and, if so, what that meaning was. The question that Associate Professor Buzzard was asked concerned the 'normal' range of ankle motion in flexion and extension. His answer to that question was based on the impaired ranges of motion specified in Table 42. The normal range of ankle motion is plain on the face of the Guides and does not need further explanation.

64 There are two kinds of cases involving claimed legal unreasonableness where further evidence may be received on judicial review. The first involves a claimed failure to make an obvious inquiry about a critical fact. The second involves a claimed absence of an intelligible foundation for the decision (or opinion) - often referred to as manifest or Wednesbury unreasonableness.[32] This 'outcome focused' form of legal unreasonableness is distinct from cases in which a specific error is said to vitiate the decision - such as consideration of irrelevant matters, failure to have regard to a mandatory consideration, or want of procedural fairness.[33]

65 Neither of those forms of legal unreasonableness is raised as a ground in this case. Rather, Ms Arik argues that the Panel's opinion was affected by the specific errors of not assessing her impairment in accordance with the Guides, and disregarding the direction given in Section 3.2 to combine the whole-person estimates of several impairments of the same lower extremity part. Those arguments turn on the proper interpretation of the Guides which, as already discussed, is a question of law.

66 Vicinity's solicitors asked Mr Dooley to provide a report responding to the following questions:[34]

(a) Please outline:

1. your training and experience in carrying out impairment assessments in accordance with the Wrongs Act and the Guides; and
2. your experience in reviewing impairment assessments conducted by other approved medical practitioners in accordance with the Wrongs Act and the Guides.

(b) Have you successfully completed the Ministerially approved training program in the application of the Guides to accredit you to conduct impairment assessments under the Guides?

(c) Did the training you have received in relation to conducting impairment assessments in accordance with the Guides include instruction on how range of motion impairment for a lower extremity part should be assessed? In particular:

1. were you trained and instructed to take the highest rating of any range of motion deficit identified in tables 40-45 of the Guides in order to determine impairment for that joint as mild, moderate or severe in the way that the Medical Panel did in this case; or
2. were you trained and instructed to attribute an individual impairment rating to each range of motion deficit identified and to then combine each rating using the combined values chart as the plaintiff alleges the Panel should have done in this case; or
3. were you trained and instructed in some other method, and if so what method?

(d) In your experience carrying out impairment assessments in accordance with the Wrongs Act and the Guides which of the methods set out in your answer to (c) above have you used to assess whole person impairment of a lower extremity body part?

(e) In your experience reviewing how other approved medical practitioners have assessed whole person impairment of a lower extremity body part, which of the methods in your answer to (c) have those practitioners used?

(f) According to your training and experience, how is the degree of range of motion impairment of a lower extremity body part (for example, flexion, extension, rotation etc.) assessed in accordance with the Guides?

(g) The purpose of the Guides is to provide standard protocols and criteria for estimating a person's degree of permanent impairment. Through the use of the protocols and criteria, the Guides aim to assist assessors to evaluate and report impairment in a standardised manner, and make as objective as possible the process of estimating impairment, so that assessments by different assessors are more likely to lead to similar results.

If whole person impairment of a lower extremity body part was to be assessed in the way contended for by the plaintiff in this case (attributing an individual impairment rating to each range of motion deficit identified and then combining each rating using the combined values chart) do you consider that:

1. it would accord with the purpose of the Guides set out above;

2. it could give rise to any risks or issues in terms of evaluating impairment of lower extremity body parts in accordance with the Guides, and if so, please quantify that risk as best you can (for example, real or remote)?

Please outline your reasoning.

(h) The plaintiff contends that the example ankle motion impairment assessment provided in section 3.2e of the Guides can only be understood to represent the combination of 3% WPI for restriction of range of motion in terms of plantar flexion with 3% WPI for extension (as opposed to the 'take the highest' approach). This is said to follow from the reference in the example to the woman losing "half of the ankle flexion and extension motion". The plaintiff contends that:

1. "normal" range of ankle plantar flexion motion is anything greater than 20 degrees up to 40 degrees;
2. therefore, a person who loses "half of that motion will have a residual ankle flexion motion of between 10.5 degrees and 20 degrees;
3. therefore, the person's WPI can only be 3% under Table 42 as it is contended that 10.5 degrees would be rounded up to 11.

In your clinical experience, is it possible or practicable to assess range of motion of a joint of the lower extremity to a half degree using a goniometer? Please explain your answer.

67 Mr Dooley was also asked whether he considered, based on his training and experience as a medical practitioner and in the Guides, that the example ankle motion impairment assessment provided in Section 3.2e of the Guides could be understood to use the 'take the highest' approach. In other words, Mr Dooley was asked whether he agreed or disagreed with the plaintiff's contention as to how that example should be understood.

68 Mr Dooley provided a report answering each of those questions.

69 It is evident from the questions asked of Mr Dooley that Vicinity intended to use much of his report in the same way that it sought to use the documents identified in the subpoena to AMA Victoria. For the same reasons that I set aside the subpoena, Mr Dooley's report was not admissible for that purpose.[35]

70 Otherwise, Vicinity sought to rely on Mr Dooley's report to respond to the evidence of Associate Professor Buzzard. It accepted that those parts of Mr Dooley's report should not be admitted if, as I did, I ruled Associate Professor Buzzard's report inadmissible.

Preliminary matter - Application to amend originating motion

71 As mentioned, in the course of the hearing Ms Arik sought leave to amend her originating motion to include a third ground of review - 'and/or acted in a legally unreasonable way having regard to the failures in (a) and (b)'. The application to amend was made orally, on the day of the trial, and without prior notice to Vicinity. Its purpose was to establish a basis for the admission of Associate Professor Buzzard's evidence as to a 'normal' range of ankle motion.

72 Ms Arik submitted that the amendment would not alter the substance of her case, which was that the Panel did not assess her impairment in accordance with the Guides because it did not combine her several hip motion impairments. The proposed new ground related to the 'very same failures' that were the subject of the written submissions already filed. The only explanation for the lateness of the application was that Ms Arik's lawyers had been of the view that her existing grounds of review already captured legal unreasonableness.

73 Vicinity was, understandably, uncertain about the extent or purpose of the proposed amendment. It submitted that the amendment should not be allowed if it went further than the existing grounds of review.

74 I refused leave to amend principally because the proposed new ground did not add anything to the existing grounds in the originating motion. As already discussed, the application to amend was based on a misconception about the different forms of legal unreasonableness.[36] Ms Arik did not seek to add a ground that the Panel's decision lacked an evident intelligible foundation, about which further relevant evidence might have been received. Her case remained that the Panel had made a specific error in its interpretation and application of the Guides.

75 I also refused leave to amend on case management grounds. There are now limits on a party's ability to reformulate a claim during a proceeding, which become more stringent in the later stages of the proceeding.[37] If the proposed new ground had expanded Ms Arik's case, it would have been unfairly prejudicial to Vicinity to allow the amendment on the day of the trial.

Preliminary matter - Extrinsic materials as an aid to interpreting the Guides

76 There is one final preliminary matter to be determined, before I can turn to the real issues in dispute. Ms Arik sought to rely on extracts from the second, third, fifth, and sixth editions of the Guides, in support of her contended interpretation of the fourth edition. Vicinity argued that regard should not be had to earlier or later editions.

77 Ms Arik characterised the Guides as a 'legislative document' - that is, a document that is adopted and applied by the Wrongs Act, which has the force of law. She cautioned that the Guides was written by expert medical practitioners and not by statutory drafters and should not be interpreted legalistically, as if it was a statute.[38]

78 She then referred to the summary of principles of statutory construction in Roman Catholic Trusts Corporation for the Diocese of Sale v WCB[39] - in particular the principle that statutory text must be considered in its context, which includes legislative history and extrinsic materials.

79 She added that it may also be appropriate to have regard to any amendments made by subsequent enactments of the statute, where the statute is open to more than one interpretation.[40]

80 Applying those principles, Ms Arik submitted, the proper interpretation of Section 3.2 of the Guides necessarily involves considering its history and context - including both earlier and later editions of the Guides.

81 Vicinity relied on the observations in Mountain Pine Furniture Pty Ltd v Taylor, as to whether later editions might inform the interpretation of the fourth edition of the Guides.[41] Justice Nettle said:[42]

I also thought for a while that it might be possible to find an explanation in later editions of the Guides, particularly in the fifth edition in which the concepts and methods of assessment involved in the injury model have been considerably developed and refined. But with the benefit again of counsel's further submissions, I can see that that idea was also without merit. Each edition of the Guides stands alone and essentially unconnected. The authorship is not necessarily common. Nor are the ideas which are involved. The Act requires the assessment of impairment to be carried out in accordance with the fourth edition and I accept that one may look no further.

82 This approach was followed by Beach J in Nicholls v Corlett,[43] in which his Honour held that a statement in the sixth edition of the Guides concerning a highest to lowest approach did not assist in the construction of the fourth edition, which contained no such statement.

83 Consistent with Mountain Pine and Nicholls, Vicinity submitted that each edition of the Guides stands alone and is essentially unconnected with other editions. It said that advances in medical knowledge over the decades have led to the adoption of different approaches to assessing impairment in different editions of the Guides. It pointed out that the authors, contributors, and editors of different sections of the Guides are not always identified and that, where they are, their identities and contributions change from edition to edition.

84 More generally, Vicinity said that it should be borne in mind that the Guides is a guide, and should not be interpreted legalistically, as if it were a statute or a legislative instrument.[44] It rejected Ms Arik's characterisation of the Guides as a legislative document, on the basis that it was not made under a statute or prepared by statutory drafters. For this reason, it said that no analogy could be drawn between the Guides and non-legislative instruments such as industrial awards and agreements, or development consents.[45]

85 Vicinity also drew attention to misgivings expressed about interpreting statutory provision by reference to subsequent amending statutes.[46]

86 The authorities are replete with cautions against interpreting the Guides legalistically, as though it were a statute drafted by legislative drafters. It is a document that provides framework and method for evaluating impairment of all kinds, prepared by expert medical practitioners, for use by other medical practitioners in a practical setting.

87 At the same time, the Guides has legislative force in Victoria. It has been prescribed by Parliament as the method to be used for assessing whether a person has a 'significant injury' for the purposes of Pt VBA of the Wrongs Act. A person's degree of impairment must be assessed 'in accordance with' the Guides, and the assessment determines whether the person can claim damages for non-economic loss in respect of an injury caused by the fault of another person.

88 Where there is a dispute about the meaning of the Guides, its proper interpretation is a question of law. That question is ultimately to be answered not by doctors, but by the Court, using established legal methods of interpretation.

89 The orthodox approach to statutory interpretation is to ascertain the ordinary meaning of the words of the relevant provision, having regard to the context and purpose of the provision.[47] Legislative history and other extrinsic materials can provide context and useful information about the purpose of a provision. A statute is to be read as a whole, on the basis that its provisions are intended to give effect to harmonious goals and that every provision has work to do.[48] The same basic approach also applies to the interpretation of a wide range of documents that are not prepared by legislative drafters but have statutory force - such as industrial agreements,[49] planning permits,[50] environmental policies,[51] and codes of practice.[52] In each case, it is permissible to have regard to extrinsic materials, including previous iterations of the document in question, as part of the context from which its words take their meaning.

90 I do not understand the passage from Mountain Pine relied on by Vicinity to establish some different interpretative approach for the Guides, or to stand for the proposition that earlier or later editions of the Guides can never be referred to as aids to the interpretation of the fourth edition. Rather, in that case, reference to later editions did not assist in resolving the particular issue of construction to be determined.

91 In Mountain Pine, there was a question about the proper interpretation of a direction in Section 3.3d, concerning the 'Injury Model' for evaluating impairments of the spine. The direction was that 'surgery to treat an impairment does not modify the original impairment estimate', which remained the same regardless of the patient's response to surgery.[53] There was an inconsistency between the terms of the direction and one of three examples given at the end of Section 3.3h, regarding cervicothoracic spine impairment, which took into account improvements after surgery. Justice Nettle was unable to construe both the direction and the example in a way that made sense of both provisions. Applying the principle that the example should not control the meaning of the direction, Nettle JA concluded that, to the extent of the inconsistency, the example should be ignored.[54] It was in this context that his Honour considered and then rejected having recourse to later editions of the Guides, which were unconnected with Section 3.3d of the fourth edition.

92 My understanding of Mountain Pine is consistent with the approach taken by Beach J in Nicholls. There, his Honour considered the express statement in the sixth edition concerning a 'highest to lowest' approach, but found that it did not assist in the construction of the fourth edition, where there was no equivalent statement. While it was permissible to have regard to another edition of the Guides, in that case it did not help answer the question of interpretation at issue.

93 I note the 'doubts and misgivings' that have been expressed about reliance on subsequent amending legislation to ascertain the meaning of a provision as it stood before the amendment.[55] I accept that a later version of a document may not provide any insight into the meaning of an earlier version, particularly in cases where an amendment has been made to remove some ambiguity. However, it remains permissible to have regard to later versions of a provision or document to interpret an earlier version, although care should be exercised in doing so.

94 For those reasons, I conclude that it is permissible to consider both earlier and later editions of the Guides, as part of the relevant context for the fourth edition. Whether they shed any light on the proper interpretation of Section 3.2 of the fourth edition will depend on the extent to which Section 3.2 of the fourth edition is connected with earlier and later versions, including by common ideas, methods, or authorship.

Was the Panel's assessment in accordance with the Guides?

95 Ms Arik's central contention was that the Panel was wrong to assess the degree of impairment of her hip by taking the highest rating of the range of motion deficits recorded on examination. Instead, she submitted, the Panel was required by Section 3.2 of the Guides to combine the measured whole-person impairment percentages for each range of movement, using the Combined Values Chart at the end of the Guides. Had the Panel done so, the calculation would have produced a total whole-person impairment percentage of 14%, which is above the 'threshold level' of more than 5%.

96 The Panel's examination findings in relation to Ms Arik's right hip equated with the whole-person impairments and ratings in Table 40 - Hip Motion Impairments as follows:

97 Ms Arik's submission that the Guides required the Panel to combine the several whole-person impairments, rather than taking the highest one, was based on the direction that appears in the introductory paragraphs of Section 3.2 - The Lower Extremity (emphasis in original):

If the patient has several impairments of the same lower extremity part, such as the leg, or impairments of different parts, such as the ankle and a toe, the whole-person estimates for the impairments are combined (Combined Values Chart, p. 322).

I refer to this as the Section 3.2 direction.

98 Ms Arik relied on what Kaye J said in Transport Accident Commission v Elworthy[56] about the effect the Section 3.2 direction, which his Honour described as 'standing alone, clear, unambiguous and intelligible':[57]

The plain meaning of those words is to require the practitioner (and thus the Tribunal and now the Court) to assess the degree of impairment to an individual, resulting from several impairments of the same lower extremity part, by combining (using the Combined Values Chart) the whole person estimates for each of those impairments.

99 Applying that approach, Ms Arik submitted that her right hip is a lower extremity part, and that each of the restrictions in the range of movement of her right hip that were measured by the Panel is, in and of itself, an 'impairment' of the right hip for the purposes of the Guides. In accordance with the Guides, each of those impairments is to be combined using the Combined Values Chart to determine Ms Arik's total whole-person impairment percentage.

100 According to Ms Arik, the 'take the highest' approach used by the Panel was inconsistent with the Section 3.2 direction and not otherwise supported by the text of the Guides. She argued that, if the authors of the Guides had intended the 'take the highest' approach to be used by assessors, they would have said so.

101 In addition, Ms Arik argued that the Panel's approach was liable to produce results that do not promote the stated objectives of the Guides, to estimate 'the severity and extent of permanent impairment and the effects of the impairment in terms of the individual's everyday activities'.[58] The Guides further states that it intends to provide a means to derive an impairment percentage representing 'an informed estimate of the degree to which an individual's capacity to carry out daily activities has been diminished'.[59] Using the Panel's approach, a person with a 4% whole-person impairment estimate for each range of motion listed for a lower extremity part would be assessed to have the same whole-person impairment of that part as a person with a 4% impairment of only one of those ranges. Ms Arik submitted that this was an absurd result that was inconsistent with the stated intent of the Guides to evaluate the extent of a person's permanent impairment and estimate the degree to which the person's ability to carry out daily activities has been diminished.

102 Ms Arik also drew support from the example impairment assessment provided in Section 3.2e - Range of Motion:

Example: A 45 year-old woman sustained a fractured tibia in a crash. Months after the injury, when the residua were stable, she had lost half of the ankle flexion and extension motion, and she had severe, permanent stiffness of all toes.

Impairment: The woman's whole-person impairments were estimated to be moderate (6%) in terms of ankle motion (Table 42, at left) and severe (2%) (Table 45, above) in terms of toe impairment. The two impairments are combined by means of the Combined Values Chart (p. 322).

Comment: Comparing Tables 42 and 45 with Table 37 (p. 77), one can see that estimated impairment for loss of motion of the ankle and toes would exceed any estimated impairment for weakness or atrophy of the leg muscles. If the impairment is estimated on the basis of ankle and toe loss of motion, it should not be estimated on the basis of muscle atrophy also. Manual muscle testing is difficult to assess because of the lower leg muscles' limited range of motion of the ankle and toes.

103 The relevant table was Table 42 - Ankle Motion Impairments:

Whole-person (lower extremity) [foot] impairment

104 Based on this table, Ms Arik submitted that the normal range of ankle flexion (or plantar flexion capability) is anything greater than 20 degrees, while the normal range of extension is anything greater than 10 degrees. As such, a person who loses half of their previously normal ankle flexion and extension motion would have the following impairments:

(a) a mild or 3% whole-person impairment arising from the ankle flexion restriction; and

(b) a mild or 3% whole-person impairment arising from the extension restriction.

105 Combining these two whole-person impairments using the Combined Values Table gives a whole-person impairment of 6% in respect of ankle motion, which is then combined with the separately assessed whole-person impairment of 2% in respect of toe. The calculation of the total whole person impairment in the example is therefore consistent with the Section 3.2 direction to combine several impairments of the same lower extremity part, as well as combining impairments of different lower extremity parts.

106 Ms Arik submitted that the total impairment of 6% in the example could not have been arrived at using the 'take the highest' approach employed by the Panel. This was based on the premise that a person who loses half their previously normal ankle flexion and extension motion would only ever be assessed as having a mild or 3% restriction for each range of motion.

107 Lastly, Ms Arik referred in some detail to the second, third, fifth and sixth editions of the Guides. She pointed out that the foreword to each edition indicates that it builds on earlier editions, and represents a revision rather than a complete replacement of the preceding edition. Further, the same person served as chair for the section on the lower extremity for both the fourth and fifth editions.

108 Specifically in relation to the range of motion method for assessing impairment of the lower extremity, Ms Arik said that the earlier and later editions all provide for impairment values for each range of motion different to be added or combined, and that no edition prescribes a 'take the highest' approach for the range of motion assessment method. She sought to demonstrate that her injury, if assessed under the range of motion model described in any of the earlier or later editions of the Guides, would be assessed as a whole person assessment of 13-14%. Ms Arik argued that it was highly unlikely that the fourth edition alone mandated an entirely different approach to assessing lower extremity impairments under the range of motion model.

109 Vicinity accepted that the Panel had adopted the highest rating of its range of motion impairment assessments of Ms Arik's hip. Its examination revealed mild to moderate restrictions in the active range of motion of the right hip and, favourably to Ms Arik, it assessed her impairment to be a 'moderate' whole person impairment. Vicinity submitted that this approach accorded with the methodology for assessing lower extremity motion impairment set out in Section 3.2e of the Guides and Tables 40 to 45.

110 Vicinity emphasised the last sentence in the introductory paragraph to Section 3.2e: 'The arcs listed are examples of mild, moderate, and severe impairments and are to be used as guides'. It said that Tables 40 to 45 classify arcs or grades of loss of motion into columns representing either mild, moderate, or severe impairment.[60] The tables require the exercise of medical judgment in determining the range of motion impairment class that best represents the extent to which range of motion of the relevant part is impaired. The exercise is not a strictly mathematical one. Vicinity stressed that adjustment may be required where the assessor considers that the range of motion measurements are affected by a patient's pain, motivation, or some other subjective factor.

111 In Vicinity's submission, Section 3.2e directs assessors to use the example grades of loss of motion and their classification in Tables 40 to 45 as mild, moderate or severe as guides when evaluating the appropriate whole person impairment of the relevant lower extremity part. Unlike the tables in Section 3.2f - Joint Ankylosis, the tables in Section 3.2e do not prescribe a methodology which involves assigning an individual whole person impairment rating to each range of motion deficit and combining them. Rather, Tables 40 to 45 group grades of loss of motion in various directions or positions into categories (mild, moderate, or severe).

112 Vicinity argued that the Section 3.2 direction relied on by Ms Arik was not a specific direction to assign an individual impairment rating to every range of motion deficit and then combine them. The direction could not displace the methodology prescribed by Section 3.2e, which Vicinity contrasted with the methodologies prescribed in other parts of Section 3.2. It drew attention to specific directions to combine different lower extremity impairments in Sections 3.2f - Joint Ankylosis, Section 3.2i - Diagnosis-based Estimates, Section 3.2k - Peripheral Nerve Injuries and Section 3.2m - Vascular Disorders. No such direction is found in Section 3.2e.

113 Vicinity sought to distinguish Elworthy, on the basis that it concerned the different issue of the correct method for combining several impairments in the plaintiff's left leg (left knee, wasting, sensory loss, left ankle and leg shortening). Elworthy decided that the correct method was to combine the whole-person estimates for those several impairments, and not the lower extremity estimates.

114 Next, Vicinity said that the example in Section 3.2e was consistent with the methodology used by the Panel. In the example, a single whole person impairment estimate is given for the woman's impaired ankle motion, which is then combined with the separate toe impairment estimate using the combined values chart. The estimate of moderate impairment for loss of motion of the ankle could be understood to have been derived on the basis that, under Table 42, loss of half of her ankle extension motion represented a mild impairment while loss of half of the ankle flexion represented a moderate impairment. Overall, the loss of motion impairment of the ankle was best estimated to be moderate rather than mild.

115 Alternatively, Vicinity submitted that if the example was inconsistent with the methodology set out in Section 3.2e and Tables 40 to 45, the methodology in the text and table must prevail.[61]

116 In relation to the earlier and later editions of the Guides, Vicinity drew attention to the multiplicity of different contributors to each edition, and the changes in those contributors between editions. It submitted that I should not take anything from the fact that the same person was chair for Section 3.2 - The Lower Extremity for both the fourth and fifth editions, or that each edition was published by the same organisation.

117 In response to Ms Arik's submission that the Guides was an iterative document, with each edition building on the preceding edition, Vicinity said that the second and third editions used an entirely different methodology from the fourth edition for measuring lower extremity impairments. The second and third edition used only range of motion as an evaluation method for the lower extremity. By contrast, the fourth edition allowed for the use of a range of evaluation methods, with the possibility of combining different methods. Further, the second and third editions provide for the combination of several lower extremity impairments, not whole-person impairments as Ms Arik contended should be combined under Section 3.2.

118 According to Vicinity, the fifth edition did not support Ms Arik's contention either. It acknowledged that Chapter 17 - The Lower Extremities contains an express direction to combine multiple impairments within the same region of the lower extremity, and then convert the combined region impairment to a whole-person impairment. However, Vicinity sought to demonstrate by a close analysis of some examples in Chapter 17 that in fact range of motion deficits should not be combined in that way.

119 Vicinity said that the sixth edition of the Guides represented a 'paradigm shift' to the assessment of impairment. Among other things, it introduced an entirely different, diagnosis-based method for assessing lower extremity impairment, and provided that range of motion should be used as a standalone assessment method only in exceptional cases.

120 For all of those reasons - in addition to the authority of Mountain Pine - Vicinity submitted that no assistance could be drawn from earlier or later editions of the Guides.

121 While the proper interpretation of the Guides is a question of law, it is important not to burden it with legalistic interpretations. In Elworthy, Kaye J identified two points to bear in mind when construing the Guides:[62]

First, as observed by Nettle J in Gillat v Transport Accident Commission, the rationale of the Guides is " ... to make as objective as possible the process of estimating impairment by reference to sufficient medical and non-medical information to justify the estimate of impairment." Thus the use of the AMA Guides is designed to promote precision, certainty and consistency.

The second point is that the AMA Guides have been written, not by statutory draftsmen, but by medical practitioners who are expert specialists in the various fields covered by the AMA Guides. They comprise a document written by medical practitioners for use by medical practitioners. It is true that the tribunal, and, on appeal, the court, are the final arbiters of the correct assessment of the impairment of a particular individual. However those decisions are based upon, and informed by, the evidence of expert medical practitioners who are required to base their estimates on the AMA Guides. In that context it is important to bear in the mind the admonition of the Court of Appeal that it is important not to overlay the AMA Guides with legalistic interpretation, for, to do so, would be to render the AMA Guides a legal "minefield" which would be of little utility to doctors and lawyers. Ordinarily, in any area of statutory construction, the plain ordinary meaning of words used by an instrument is preferred. In the context of the AMA Guides, it is, I consider, of paramount importance to be faithful to the plain words used by the text, and to avoid "torturing" those words by a technical and legalistic approach.

122 Beginning with the words of Section 3.2, there is a clear direction given in the fifth paragraph of the introduction about the method to be used for assessing a patient with several different impairments of the lower extremity. It is worth repeating the Section 3.2 direction:

If the patient has several impairments of the same lower extremity part, such as the leg, or impairments of different parts, such as the ankle and toe, the whole-person estimates for the impairments are combined (Combined Values Chart, p 322).

123 I respectfully agree with Kaye J that the plain meaning of those words is 'clear, unambiguous and intelligible'.[63] They apply in circumstances where a patient has several impairments of the same lower extremity part. In those circumstances, the assessor is directed to combine the whole-person estimates for each of those impairments. The example given is the leg, but the direction applies equally to the other lower extremity parts - namely, the hip, the knee, the ankle, the hindfoot and the foot.

124 By contrast, the meaning contended for by Vicinity is not supported by the plain meaning of the Section 3.2 direction, or the words of Section 3.2e - Range of Motion. Vicinity's interpretation is the more legalistic and technical of the two competing interpretations. It would involve ignoring the plain words of the Section 3.2 direction, while also reading words in to Section 3.2e. In particular, Section 3.2e does not instruct assessors to disregard the Section 3.2 direction when using the range of motion method, and nor does it say to take the highest rating where there are several impairments of the same lower extremity part. The words in Section 3.2e that were emphasised by Vicinity - 'The arcs listed are examples of mild, moderate, and severe impairments and are to be used as guides' - do not carry those meanings. Vicinity's interpretation would involve overlaying Section 3.2 of the Guides with a legalistic interpretation, and for that reason is not to be preferred.

125 The structure of Section 3.2 provides relevant context supporting the interpretation advanced by Ms Arik. The Section 3.2 direction appears in the introduction to Section 3.2, and so applies to the entire section. It is the case that the direction is repeated or elaborated upon in the description of some evaluation methods, in particular Sections 3.2f - Joint Ankylosis, Section 3.2i - Diagnosis-based Estimates, Section 3.2k - Peripheral Nerve Injuries and Section 3.2m - Vascular Disorders. However, that does not mean that the Section 3.2 direction does not apply to those evaluation methods where it is not specifically restated. In addition to Section 3.2e - Range of Motion, there is no specific direction to combine estimates for several impairments of the same lower extremity part in Section 3.2c - Muscle Atrophy (Unilateral), or Section 3.2d - Manual Muscle Testing. Both of those evaluation methods contemplate that the same lower extremity part may be impaired in different ways. Equally, the Range of Motion evaluation method in Section 3.2e provides a method for assessing various impairments of each of the lower extremity parts. The direction to combine several impairments of the same part applies to each evaluation method.

126 Further context is provided by the headings to the various tables that correspond with the different evaluation methods provided in Section 3.2. The heading of each of Tables 40 to 45 in Section 3.2e - Range of Motion refers to 'Impairments' of the relevant body part, in the plural. In each case, the different types of impairments are listed in the left hand column of the table. The right hand column lists the whole-person impairment estimates that can be assigned to each of the several impairments. Within the right hand column are two or three sub-columns for the different degrees of impairment - mild, moderate and severe.[64] The same structure is used for many other tables in Section 3.2.[65] By contrast, Table 36, in Section 3.2b - Gait Derangement and Tables 46 to 59 in Section 3.2f - Joint Ankylosis, each of which concerns only one possible impairment, use the singular 'Impairment' in the headings.

127 I do not accept Vicinity's submission that the plural 'Impairments' in the headings to Tables in Section 3.2 refers to the spectrum of impairments in terms of mild, moderate and severe. The scheme of Section 3.2 as a whole does not involve assigning a patient's degree of impairment of the lower extremity to one of those three categories. It provides various evaluation methods for estimating the patient's degree of whole-person impairment, expressed as a percentage. While some of those methods use the categories of mild, moderate and severe, others do not. For example, Table 35 in Section 3.2a - Limb Length Discrepancy provides five different ranges, depending on the length of the discrepancy. Similarly, Tables 38 and 39 in Section 3.2d - Manual Muscle Testing provide five different grades of muscle function, with percentage whole-person impairment estimates for all five grades across each of the different impairments listed in the left hand column. Table 64 in Section 3.2i - Diagnosis-based Estimates uses mild, moderate, and severe for some impairments, while for others it uses different ranges, such as partial or total, good result or poor result, and degrees of angulation.

128 As was the case in Mountain Pine, the Section 3.2 direction is 'expressed in clear and emphatic terms', and its plain meaning cannot be overridden by an example.[66] However, in this case there is no apparent conflict - the example given in Section 3.2e is consistent with the plain meaning of the words of the direction. Assuming that the woman in the example had normal range of motion in her ankle before the injury,[67] loss of half of her flexion and extension motion would be a mild or 3% whole-person impairment of each range of motion. Combining these impairments gives a moderate or 6% impairment of ankle motion. It is only possible to interpret the example in a way that is consistent with the 'take the highest' approach by assuming facts that do not appear from the text of the example - for example, that the woman had a less than normal range of motion in her ankle before the injury.

129 I also consider that the interpretation of Section 3.2 advanced by Ms Arik is consistent with the Guides' purpose of promoting objectivity and consistency in evaluating degree of impairment. Section 3.2 of the fourth edition of the Guides requires the exercise of medical judgment, first and foremost in the selection of the most appropriate evaluation method to evaluate the particular impairment. However, once the range of motion method has been selected, Section 3.2e provides a measurement-based method for evaluating impairment. Where an assessor obtains reliable and consistent measurements from a patient, Tables 40 to 45 allow for an objective and consistent evaluation of the patient's degree of impairment. Where several impairments of the same lower extremity part have been measured, the Section 3.2 direction provides an objective and consistent means of evaluating the overall whole-person impairment.

130 There remains room for clinical judgment about the reliability of the measurements obtained. As stated in Section 3.2e, there is no need for multiple evaluations if it is clear to the assessor that a range of motion restriction has an organic basis. If the assessor has doubts, those doubts may be removed by consistent measurements taken on more than one occasion. If the assessor forms the view that the results are affected by subjective factors such as pain or motivation, a different evaluation method may be more appropriate.

131 The conclusion that I have reached about the interpretation of Section 3.2 of the Guides, based on its text, context and purpose, is confirmed by reference to the second, third and fifth editions of the Guides. I accept Vicinity's submission that the sixth edition represents a 'paradigm shift' in the assessment of impairment, and provides no assistance in interpreting the fourth edition.

132 Leaving the sixth edition aside, the following may be noted about the evolution of the Guides between the second and fifth editions:

(a) Each edition was published by the American Medical Association, drawing on input from a wide range of members and professional associations.

(b) In the second and third editions, the primary method for evaluating impairment of the lower extremity is based on range of motion. In relation to each lower extremity part, there is explicit instruction to add the impairment values of the lower extremity contributed by all ranges of motion for that part, and then to combine the impairment values for all lower extremity parts using the Combined Values Chart.

(c) The foreword to the fourth edition identifies some new features, which do not include a revised approach to evaluating impairment based on range of motion. The chair for the chapter on the lower extremity was James V Luck Jr, MD, of the Orthopaedic Hospital, Los Angeles, California.

(d) The preface to the fifth edition says that it 'has retained the focus of earlier editions, while incorporating updates in diagnostic criteria, clarifying key definitions and applications of the Guides, and enhancing readability, accessibility and consistency'. The preface emphasises some of the updated features of the fifth edition which, again, do not include a revised range of motion method. The chair for the lower extremities chapter remained James V Luck Jr, MD.

(e) Chapter 17 of the fifth edition concerns the lower extremities. The introduction to the chapter identifies five revisions in the fifth edition:

(1) The principles of assessment have been expanded to clarify when the different evaluation methods should be used; (2) a new table, Guide to the Appropriate Combination of Evaluation Methods (Table 17-2), has been added to indicate which methods are appropriate to use in combination; (3) the evaluation of causalgia and complex regional pain syndrome now follows the same principles used to evaluate central nervous system lesions; (4) additional case examples are provided; and (5) a lower extremity worksheet is provided as a template to simplify making the assessment and recording the evaluation.

Notably, these revisions do not include any change to the range of motion method of assessment.

(f) Chapter 17 of the fifth edition provides a more detailed explanation of converting from lower extremity to whole-person impairment, at Section 17.2a. It states:

Some individuals may have several impairments involving different parts of the same lower extremity; others may have several impairments of the same lower extremity part. If there are several impairments involving different regions of the lower extremity (eg, the thigh and the foot), evaluate each impairment separately, convert these regional impairments to whole person impairments, and combine the whole person impairment rating using the Combined Values Chart (p. 604). If there are multiple impairments within a region (eg, the toes and the ankle), combine these regional, lower extremity impairments of the foot and convert the combined foot impairment to a whole person impairment. Similarly, when using separate methods on the same region, combine the regional impairments before converting to a whole person impairment rating.

The 13 assessment methods listed in Table 17-1 are discussed separately below.

(g) The text of the first paragraph of Section 17.2f Range of Motion in the fifth edition is in very similar terms to Section 3.2e of the fourth edition:

Lower extremity impairment can be evaluated by assessing the range of motion of its joints, recognizing that pain and motivation may affect the measurements. If it is clear to the evaluator that a restricted range of motion has an organic basis, three measurements should be obtained and the greatest range measured should be used. If multiple evaluations exist, and there is inconsistency of a rating class between the findings of two observers, or in the findings on separate occasions by the same observer, the results are considered invalid. Figures 17-1 to 17-6 illustrate one method of measuring range of motion in the lower extremity. The ranges listed in Tables 17-9 through 17-14 are examples of mild, moderate, and severe impairments and are to be used as guides.

(h) This is followed by a further passage, which has no equivalent in the fourth edition:

Range-of-motion restrictions in multiple directions do increase the impairment. Add range-of-motion impairments for a single joint to determine the total joint range-of-motion impairments. For example, hip motion is evaluated and any impairment added in each of the six principal directions of motion.

133 It is apparent that the second, third and fifth editions all provide for the combination of impairment estimates of range of motion deficits in several directions for the same lower extremity part. The second and third editions combine the lower extremity impairment estimates, while the fifth edition combines whole-person impairment estimates. Noting that difference, it remains the case that all three editions require the estimates to be combined, and that none directs a 'take the highest' approach. As Ms Arik submitted, it is most unlikely that the fourth edition alone introduced a 'take the highest' approach to estimating impairment by the range of motion method.

134 The question of interpretation here is different from the question considered in Mountain Pine, and the reasons why Nettle JA found it unhelpful to compare the spinal chapters of fourth and fifth editions of the Guides are not present in this case. There is no quantum leap or paradigm shift between the range of motion method between the second and fifth editions of the Guides. Each successive chapter on the lower extremity built on the previous chapter, with the range of motion method appearing in all four editions. The same person was the chapter chair for the fourth and fifth editions, which confirms my impression that the additional paragraph in Section 17.2f of the fifth edition was a clarification rather than a change of approach.

135 For those reasons, I have concluded that the Panel did not assess Ms Arik's degree of impairment in accordance with the Guides, as required by s 28LH of the Wrongs Act. It should have combined the whole-person impairment estimates for the several range of motion restrictions it measured in her right hip, rather than determining her degree of impairment by taking the highest rating. This amounted to a jurisdictional error in the formation of the Panel's opinion.

136 I will make an order in the nature of certiorari, quashing the Panel's determination of 1 July 2021.

137 I will also make an order in the nature of mandamus remitting the referred medical question to the Convenor of Medical Panels to be reconsidered in accordance with law. At trial, Ms Arik did not seek an order that the medical question be remitted to a differently constituted medical panel, and Vicinity did not identify any reason why that should occur.[68] In this case I consider it appropriate to leave that issue for the Convenor to decide. It may be possible for the Convenor to reconvene the original Panel, which may be able to form its opinion on the referred medical question in accordance with law without needing to re-examine Ms Arik.

138 I will hear the parties on the question of the costs of the proceeding.

[1] Wrongs Act 1958 (Vic), s 28LE.

[2] Wrongs Act, s 28LF(1). The 'threshold level' is defined in s 28LB, and described at [22] below.

[3] Pursuant to Wrongs Act, s 28LWE.

[4] Wrongs Act, s 28LG.

[5] Workplace Injury Rehabilitation and Compensation Act 2013 (Vic) (WIRC Act), ss 537(2)-(3)(a).

[7] Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 43; (2013) 252 CLR 480, [47]; Colquhoun v Capital Radiology Pty Ltd [2013] VSCA 58; (2013) 39 VR 296, [14]-[16], [18]; Maimonis v Bourke [2019] VSCA 302, [51](1).

[8] Wrongs Act, s 28LB - definition of 'medical question'.

[9] Wrongs Act, s 28LZH(1).

[10] Wrongs Act, s 28LZH(2).

[11] [2013] VSC 196, [22]-[29] (footnotes omitted).

[12] See eg, Adams v Wadesley [2018] VSC 304, [27]; Hart v Melbourne Underwater World Pty Ltd [2018] VSC 394, [8]; La Rosa v Patrick [2022] VSC 404, [50]-[51].

[13] Gamble v Emerald Hill Electrical Pty Ltd [2012] VSCA 322; (2012) 38 VR 45, [53].

[14] Pursuant to r 42A.08 of the Supreme Court (General Civil Procedure) Rules 2015 (Vic). The letter also objected to production and inspection of the documents, pursuant to r 42A.07 of the Rules, although that procedure is only available to the addressee of a subpoena or a person with a sufficient interest other than a party.

[15] Wrongs Act, s 28LG and s 28LB (definition of 'approved medical practitioner').

[16] [2003] VSC 15; (2003) 19 VAR 376.

[17] [2004] VSC 324.

[18] [2012] VSCA 179; (2012) 37 VR 232, [37]-[40].

[19] [2022] VSC 129 (O'Connell).

[21] Referring to Woolworths Ltd v Svajcer [2013] VSCA 270, [16].

[22] Interpretation of Legislation Act 1984 (Vic), s 35(b), and see generally Perry Herzfeld and Thomas Prince, Interpretation (Lawbook, 2nd ed, 2020), Chapter 8 - Extrinsic Material (Herzfeld and Prince).

[23] At [76]-[9494].

[24] Mackenzie v Head, Transport for Victoria [2021] VSCA 100, [153].

[25] Schmael v Leach [2020] VSC 562, [22]-[23].

[27] [2013] VSCA 235; (2013) 42 VR 434 (Elsdon).

[28] Elsdon, [85] (Bongiorno JA and Dixon AJA); cf [41]-[43] (Maxwell P).

[29] Elsdon, [84] (Bongiorno JA and Dixon AJA); see also [42] (Maxwell P).

[30] Extracted at [102102] below.

[31] Referring to Minister for Immigration and Citizenship v Li [2012] HCA 61; (2013) 249 CLR 332, [27] (French CJ).

[32] Mackenzie, [153](2), (5), quoted at [5454] above.

[33] For explanations of the distinction see, eg, Li, [26]-[28] (French CJ), [64]-[76] (Hayne, Kiefel and Bell JJ) and Minister for Immigration and Border Protection v Eden [2016] FCAFC 28; (2016) 240 FCR 158, [58]-[65], in particular [60]-‍[61].

[35] See [45]-[51] above.

[36] See [64]-[65] above.

[37] Northern Health v Kuipers [2015] VSCA 172, [28].

[38] Elsdon, [49] (Bongiorno JA and Dixon AJA), quoting HJ Heinz Company Australia Ltd v Kotzman [2009] VSC 311, [24]-[28].

[39] [2020] VSCA 328; (2020) 62 VR 234, [93]-[96] (Diocese of Sale v WCB).

[40] Deputy Federal Commissioner of Taxes (South Australia) v Elder's Trustee and Executor Company Ltd [1936] HCA 64; (1936) 57 CLR 610, 625-6.

[41] [2007] VSCA 146; (2007) 16 VR 659, [31] (Nettle JA, Vincent and Ashley JJA agreeing) (Mountain Pine).

[42] Mountain Pine, [31] (Nettle JA, Vincent and Ashley JJA agreeing).

[43] (2010) 32 VAR 274, [36](c).

[44] Referring to HJ Heinz, [26], Elsdon, [49] (Bongiorno JA and Dixon AJA), and Transport Accident Commission v Weigert (2010) 33 VAR 393, [17]; Lake v Transport Accident Commission [1998] 1 VR 616, 626 (Phillips JA).

[45] Discussed in Herzfeld and Prince, Ch 16 - Non-Legislative Instruments.

[46] Referring to Dennis C Pearce and Robert S Geddes, Statutory Interpretation in Australia (LexisNexis Butterworths, 8th ed, 2014), [3.34] (Pearce and Geddes).

[47] See the summary of principles in Diocese of Sale v WCB, [93]-[96] and the authorities cited.

[48] Project Blue Sky (1998) 194 CLR 355, [70]-[71] (McHugh, Gummow, Kirby and Hayne JJ).

[49] See eg, Amcor Ltd v Construction, Forestry, Mining and Energy Union [2005] HCA 10; (2005) 222 CLR 241, [30] (Gummow, Hayne and Heydon JJ); see also [13] (Gleeson CJ and McHugh J), [66] (Kirby J).

[50] See eg, Vestey v Warrnambool City Council [2008] VCAT 963; (2008) 160 LGERA 204, [30]-[48].

[51] See eg, Mount Atkinson Holdings Pty Ltd v Landfill Operations Pty Ltd [2020] VSCA 332, [114].

[52] See eg, Kinglake Friends of the Forest Inc v VicForests (No 2) (2022) 251 LGERA 256, [89]-[92].

[53] Mountain Pine, [19] (Nettle JA, Vincent and Ashley JJA agreeing), quoting Section 3.3d of the Guides.

[54] Mountain Pine, [33] (Nettle JA, Vincent and Ashley JJA agreeing).

[55] See Pearce and Geddes, [3.34] and the authorities discussed.

[56] [2007] VSC 48; (2007) 26 VAR 146 (Elworthy).

[58] Referring to the Guides to the Evaluation of Permanent Impairment (American Medical Association, 4th ed, 1995) Section 2.3 - General Comments on Evaluation (Guides).

[59] Referring to the Guides, Section 1.1 - Impairment, Disability, Handicap, quoted at [32] above.

[60] Except in tables 43 and 45 the moderate and severe categories are combined.

[61] Referring to Mountain Pine, [33] (Nettle JA, Vincent and Ashley JJA agreeing).

[62] Elworthy, [20]-[21] (citations omitted).

[64] Tables 43 and 45 contain only two sub-columns within the whole person impairment column - one for mild, and the second for moderate and severe.

[65] See Table 37 in Section 3.2c - Muscle Atrophy; Table 39 in Section 3.2d - Manual Muscle Testing; Table 62 in Section 3.2g - Arthritis; Table 63 in Section 3.2h - Amputations; Table 67 in Section 3.2j - Skin Loss; and Table 68 in Section 3.2k - Peripheral Nerve Injuries.

[66] Mountain Pine, [33] (Nettle JA, Vincent and Ashley JJA agreeing).

[67] That is, plantar flexion capability of more than 20° and extension of greater than 10°.

[68] Vegco Pty Ltd v Gibbons [2008] VSC 363; (2008) 30 VAR 1, [33].