Grantham v Department for Correctional Services [2025] SAET 131

1. The following question of law has been referred to a Full Bench of this Court pursuant to s 22 of the South Australian Employment Tribunal Act 2014 (SAET Act) by a learned Deputy President Judge (Judge):

Whether, for the purposes of an assessment of whole person impairment in connection with the aftermath of bilateral carpal tunnel surgery, and on the proper construction of scenario 1 set out at page 495 of AMA 5, and having regard also to chapter 2.11 of the Impairment Assessment Guidelines, it is open as a matter of law for an assessor to be satisfied that there are "[p]ositive clinical findings of median nerve dysfunction and electrical conduction delay(s)" in the absence of any post-surgery nerve conduction studies?

1. The question of law arises in the context of the applicant worker, Christopher Grantham, seeking lump sum compensation for permanent impairment from his employer, Department for Correctional Services. Mr Grantham is a corrections officer who has an accepted claim for bilateral carpal tunnel syndrome (CTS) injuries. Mr Grantham underwent surgery to his right carpal tunnel in September 2020 and to his left carpal tunnel in October 2020.
2. The reference to AMA5 in the question of law is a reference to a publication of the American Medical Association entitled, Guides to the Evaluation of Permanent Impairment, Fifth Edition. AMA5 was used to assess Mr Grantham's whole person impairment (WPI) under the Return to Work Scheme Impairment Assessment Guidelines (IAG) published in March 2015 under s 22(3) of the Return to Work Act 2014 (RTW Act). Section 22(3) provides:

The Minister will publish guidelines (the Impairment Assessment Guidelines) for the purposes of the assessment of permanent impairment (being whole person impairment).

1. Chapter 1.3 of the IAG authorises the use of AMA5:

The Guidelines adopt AMA5 in most cases. Where there is any deviation, the difference is defined in the Guidelines. Where differences exist, the Guidelines are to be used as the modifying document. The procedures contained in the Guidelines are to prevail if there is any inconsistency with, or difference from, AMA5.

The assessment of carpal tunnel syndrome post-operatively is undertaken as set out in AMA5 except that Scenario 2 (AMA5, p495) is replaced by the following: Where there is normal sensibility and opposition strength with residual carpal tunnel syndrome symptoms, not meeting scenario 1 (AMA 5 p495), an impairment rating not to exceed 5% of the upper extremity may be justified with rationale provided for allocation within the range.

1. The left column of page 495 of AMA5 describes how impairment resulting from CTS is assessed in this way:

Carpal Tunnel Syndrome

The carpal tunnel syndrome (CTS) is the most common of nerve compression lesions and involves the median nerve at the volar aspect of the wrist. There are many presentations of CTS. Pain and paresthesias in the median nerve distribution of the hand are the usual symptoms. Pain may radiate proximally. Nocturnal paresthesias, relieved by shaking the hand, are frequently reported and can be the only symptom in the earliest stages of nerve pathology. True sensory disturbances and muscle atrophy represent later stages, when axonotmesis with axonal degeneration is also present. The symptoms, signs, and findings may include sensory or autonomic disturbances of the radial 3½ digits, weakness or atrophy of the thenar muscles, a positive percussion sign at the wrist, presence of Phalen's signs, and motor and sensory electroneuromyographic abnormalities. Not all symptoms are necessarily present in any one case. In isolated involvement of the recurrent branch of the median nerve, there is weakness of thumb abduction and thenar atrophy without any sensory disturbance in the hand. Sensitivity to cold may be a major presenting symptom of CTS. Certain cases may be associated with reflex dystrophy (CRPS I). It has also been reported that 5% of individuals with CTS may have normal electrophysiologic studies.

If after an optimal recovery time following surgical decompression, an individual continues to complain of pain, paresthesias, and/or difficulties in performing certain activities, three possible scenarios can be present:

1. Positive clinical findings of median nerve dysfunction and electrical conduction delay(s): the impairment due to CTS is rated according to the sensory and/or motor deficits as described earlier.
2. Normal sensibility and opposition strength with abnormal sensory and/or motor latencies or abnormal EMG testing of the thenar muscles: a residual CTS is still present, and an impairment rating not to exceed 5% of the upper extremity may be justified.
3. Normal sensibility (two-point discrimination and Semmes-Weinstein monofilament testing), opposition strength, and nerve conduction studies: there is no objective basis for an impairment rating.

1. The question of law asks whether under scenario one on page 495 of AMA5 (scenario one), an impairment assessor can be satisfied that there are positive clinical findings of median nerve dysfunction and electrical conduction delay(s) in the absence of post-surgery nerve conduction studies being undertaken.
2. Counsel were asked very early in the hearing whether all facts that may be relevant to answering the question of law had been found. This exchange was one of several on that issue:[2]

CALLIGEROS DPJ: Mr Blewett, do we need to rely on a finding of fact to determine whether the Semmes-Weinstein testing is capable of determining whether there is median nerve dysfunction and electrical conduction delay or delays and in particular the latter. Has his Honour made that finding?

MR BLEWETT: I don't think his Honour went quite that far. His Honour at page, paragraph 59 I think.

CALLIGEROS DPJ: Paragraph 59?

MR BLEWETT: Paragraph 59 on page 14 of the book, where his Honour records, halfway down the paragraph,

My impression of her evidence was that she thought that the Semmes-Weinstein monofilament testing was sufficient and that she was entitled to use her clinical judgement in concluding that there must have been electrical conduction delays.

His Honour doesn't go beyond that I don't think in the judgement as to whether or not that did as a matter of fact constitute a finding of electrical conduction delay.

CALLIGEROS DPJ: My question for you and my concern about us dealing with this in the nature of the referral is that do we then have to make a supposition about what that finding is? I'm just concerned about the ambit of this.

MR BLEWETT: I think your Honour, the question of law is carefully phrased, whether it's open to an assessor to determine the existence of positive clinical findings of median nerve dysfunction and electrical conduction delay without there being post-operative nerve conduction studies. So I don't think your Honours have to be troubled with the question whether here the findings amount to that thing. It is rather whether it is open to an assessor to do so. The assessor clearly thought she could do so. There is not an actual finding as to whether she had done so, but that's why I think the question's been phrased in the way it is been phrased.

1. After that exchange Mr Blewett was asked by another member of the Full Bench whether the views and answers to questions given by the medical experts who gave evidence before the Deputy President might be relevant to construing the meaning of scenario 1:[3]

MR BLEWETT: Well, I suppose the first answer to your Honour's question is really the one I have given, which is I don't think that arises on the question of law, which is, is it open to an assessor to do that?

KELLY DPJ: But in deciding that and working out what, trying to work out what scenario 1 means, which we do have to do, if we have questions which necessarily have a medical expert answer, in a situation where we know that the two experts called before Judge Gilchrist had a different view, it would seem, then aren't we straying into a question of expert evidence in trying to construct what scenario 1 means?

1. AMA5 is not legislation, and the approach a court takes when construing legislation does not necessarily apply to construing a document that is not legislation. The difference between statutory construction and the construction of other documents has been recognised in relation to the interpretation of industrial awards:[4]

There are well developed principles concerning the construction of industrial awards and agreements, which take account of the fact that they are commonly drafted by lay persons and lack the precision and clarity to be expected in commercial contracts.

The principles were reviewed recently by Tracey J in Transport Workers' Union of Australia v Linfox Australia Pty Ltd [2014] FCA 829; (2014) 318 ALR 54 at [29]- [41]. It is not necessary to repeat the principles in detail in these reasons. It is sufficient to say that the Court will seek to identify, in an objective way, the meaning intended by the parties to the agreement having regard to the language they have used and, in doing so, avoid a narrow or pedantic approach. In particular, the Court takes account of the circumstance that the drafters of the agreement were likely of a "practical bent of mind" and likely to have been concerned with expressing their intentions in ways understood in the context of the relevant industry and industrial relations environment. As with commercial contracts, the Court will prefer a construction which gives effect to the presumed purpose of the parties.

1. The Court of Appeal has cited with approval the reliance of this Court on that passage in construing an award in an additional compensation claim.[5]
2. AMA5 is not a legislation. It is a text written by medical experts for use by medical experts. Its purpose is to create a "standardized, objective approach to evaluating impairments".[6] Fulfilling that purpose means that an orthopaedic injury, a brain injury or a dermatitis can all be expressed in terms of WPI, and can all correspond logically in terms of the degree of WPI expressed for each injury or condition. To achieve that, AMA5 adopts a wide range of assessment methodologies. Assessments are all made by medical experts and the language employed is the language used by a medical expert, not a Parliamentary draftsperson or a lawyer.
3. While both counsel encouraged us to answer the referred question of law, I remain concerned that providing an answer without all findings of fact being made may lead to error. Analysing the findings made to date and the findings that need to be made explains why that is so.

1. The Judge heard this matter on 5 and 6 May 2025 and published reasons on 19 June 2025.[7] His Honour had reservations about some of the findings made by the impairment assessor, Dr Brown, and resolved to refer Mr Grantham for an assessment of permanent impairment by an Independent Medical Adviser under s 121 of the RTW Act.[8]
2. The Judge described his "impression" of the evidence of Dr Brown in para [59] of the decision. His Honour used the same word in describing the evidence of Dr Champion in paras [61] and [65]. As Mr Blewett observed, the Judge did not make a finding in para [59] of the decision that the SWMT can be used to confirm there is electrical conduction delay.
3. The Judge observed that Dr Champion did not consider that the Semmes-Weinstein monofilament test (SWMT) was appropriate to assess permanent impairment, but is used to test the progress of, and recovery from, nerve damage.[9] It is not clear whether Dr Champion thought the SWMT was not appropriate to test nerve dysfunction altogether, or whether he thought nerve conduction studies were required post-surgery to assess whether there was any electrical conduction delay.
4. Dr Brown disagreed with Dr Champion in her report of 1 February 2025:[10]

You state that Dr Champion suggests that monofilament testing to test for sensory loss is unreliable. I disagree. Firstly, I doubt the AMA Guides would recommend use of an unreliable test. I consulted the internet, and found an article dated 27 January 2021:" Validity and Reliability of these Semmes-Weinstein Monofilament Test and the Thumb Localizing Test in Patients With Stroke", published in Frontiers in Neurology.

The reliability and validity of the Semmes-Weinstein Monofilament Test were verified in this research. A copy of the paper is enclosed.

1. The paper describes the SWMT in this way:[11]

The SWMT is considered a simple and inexpensive touch threshold test and is widely used by clinicians to evaluate sensory disturbances in of neuropathic diseases, such as diabetes mellitus, and carpal tunnel syndrome. Its reliability and validity in patients with those diseases have been confirmed in previous research...

1. In that passage, Dr Brown understands Dr Champion to take issue with the use of the SWMT to test for sensory loss. Dr Champion may take issue with using the SWMT to test for sensory loss, or he may take issue with its use to test for electrical conduction delay, or both. The paper Dr Brown describes concerns light touch sensation and somatosensory function. Testing for the presence of those things is presumably different to testing for the presence of electrical conduction delay. Without having findings made on that issue and in relation to the different views of Dr Brown and Dr Champion, answering the question of law may lead to error as we may need to make a finding on that issue, or assume what the Judge has found. The transcript of the hearing was not provided to us, but even if we were to consider it, we cannot make findings of fact. If the current state of the evidence does not allow the Judge to decide the issue further, the assessment of WPI can be referred to an IMA with the present findings.
2. In Schinckel v Return to Work Corporation of South Australia,[12] the Court of Appeal was critical of a Full Bench of this Court as it was found to have made a finding of fact in an appeal limited to a question of law:[13]

... On an appeal limited to a question of law, for the reasons explained above, it was not open for the Full Bench to make a finding, on the basis of the evidence before the trial judge, that the date of injury was 1 December 2009. This finding exceeded the jurisdiction of the Full Bench on an appeal on a question of law.

1. The referral of this matter under s 22 of the SAET Act is on a question of law.
2. In referring the question of law to a Full Bench, the Judge was attempting to avoid a potential legal problem. In an earlier decision of this Court, Burda v Thomas Foods International Consolidated Pty Ltd,[14] it was held that the language of scenario 1 requires that nerve conduction studies must be undertaken to make an assessment in a case like this. Counsel for the worker in Burda submitted that scenario 1 did not require that result.
3. Immediately after deciding that a referral to an IMA was required,[15] the Judge said this:[16]

That then leaves for consideration the issue in connection with post-operative nerve conduction studies and Burda. In connection with this, I do not accept the submission that Burda is either right or wrong and that if I conclude that it is wrong, I am free to ignore it. The fact is, that in matters of the construction of words, reasonable minds might differ as to their meaning. It has been held in several cases that a difference of opinion about how words are to be construed, will generally be insufficient to warrant a conclusion that an earlier or existing interpretation is "plainly wrong".

(citations omitted)

1. The Judge then referred to Pond v WorkCover/Allianz Australia (Wunda Joinery),[17] and Return to Work Corporation of South Australia v Hill.[18] In describing how the doctrine of stare decisis applied the Workers Compensation Appeal Tribunal, the Full Bench in Pond said:[19]

Drawing upon these observations it follows that a single Presidential Member of the Tribunal is bound to follow an indistinguishable decision of the Full Bench of the Tribunal. A single Presidential Member of the Tribunal is generally bound to follow an earlier decision of a single Presidential Member of the Tribunal unless that single Member in the later case is convinced that the earlier decision is plainly wrong. If, however, a single Presidential Member was of that view, it might be considered appropriate to make an application to the President pursuant to s 94A(2) of the Act for the issue regarding the correctness of that earlier decision to be determined by the Full Bench.

1. I do not seek to qualify the importance of those comments, but different considerations apply here and render this case unsuitable for providing an answer to the question of law. The answer to the question of law may turn on the findings ultimately made by the Judge on the evidence or it may turn on the view of the IMA who assesses Mr Grantham's WPI. Those are matters for the Judge to decide, not this Full Bench. This is not purely an exercise in the construction of AMA5. An understanding and an application of the medical evidence is required.
2. In construing a document drafted for doctors by doctors, the medical evidence led on the issue must be considered and findings of fact made before we should answer the question of law. His Honour's concern about adhering to Pond is understandable, but that concern is outweighed by the potential for this Full Bench to exceed its jurisdiction.
3. In any case, there is an important distinction between this case and Burda. The Deputy President who decided Burda did not have the benefit of hearing any oral evidence from a medical expert about the ambit of scenario 1.
4. I decline to answer the question of law. The proceeding should be remitted to the Judge to make findings about the medical evidence and to consider whether the construction of scenario 1 should be decided now or after referral to an IMA.

1. I would decline to answer the question of law for the reasons given by Calligeros DPJ. I would remit the matter to the trial Judge to consider whether the construction of scenario 1 should be decided now or after referral to an IMA

[1] Paschalis v Return to Work Corporation of South Australia & Anor [2021] SASCFC 44 Livesey and Bleby JJ [212], citing Kyrou J in H J Heinz Company Limited v Kotzman [2009] VSC 311[24]-[28]. South Australia Employment Tribunal Act 2014 s 22.

[4] Qube Ports Pty Ltd v Maritime Union of Australia [2018] FCAFC 72 [64]- [65] (White J, Mortimer and Bromwich JJ agreeing).

[5] Kimber v CE, Department of Treasury and Finance [2021] SASCA 133 [45].

[7] Grantham v Department for Correctional Services [2025] SAET 57 (Decision).

[11] Mabu Suda et al, 'Validity and Reliability of the Semmes-Weinstein Monofilament Test and the Thumb Localizing Test in Patients With Stroke' (2021) volume 11, Article 625917 Frontiers in Neurology, 2.

[12] [2023] SASCA 32.

[14] [2020] SAET 160.

[17] [2001] SAWCT 69.

[18] [2024] SAET 113.

[19] [2001] SAWCT 69 [15].