Weekly payments of compensation and the cost of benefits payable under Division 2 of Part VI of the Workers Rehabilitation and Compensation Act 1988 are not to be paid by the employer in respect of the worker's claim for compensation from the date of these orders.

Workers compensation - entitlement to compensation - whether reasonably arguable case.

Workers Rehabilitation and Compensation Act 1988; s 81A,

St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90;

Bradshaw v Tasmania Networks Pty Ltd [2020] TASFC 2;

Vos Construction and Joinery Pty Ltd v Norton-Smith [2016] TASSC 38;

Lamont v MRD Supermarkets Pty Ltd [2016] TASSC 16;

Long v Kmart Australia Ltd [2016] TASSC 6;

Federal Broom Company Pty Ltd v Semlitch [1964] HCA 34;

Rural Press Pty Ltd v H. [2022] TASCAT 22;

Bradshaw v Tasmania Networks Pty Ltd [2019] TASSC 41

The decision has been anonymised for the purpose of publication.

1. The worker is employed as a dentist. On 21 July 2025 the worker made a claim for workers compensation in relation to what she described as a strain injury to her left lower arm from repetitive retraction at work as a dentist. In the claim form she described her injuries as a "left wrist ganglion cyst, left hand side tennis elbow symptoms, left wrist and forearm weakness and occasional tingling sensation from left hand side elbow down to fingers".
2. The claim was supported by an initial workers compensation medical certificate which recorded the worker's symptoms of "Chronic left wrist and forearm pain. Loss of grip strength. Reduced flexion". The diagnosis contained in the initial certificate was "Left tennis elbow. Left dorsolateral ganglion cyst. Chronic tendinitis". The worker was certified to be fit for suitable alternative light duties in the form of office based work.
3. The employer elected to dispute liability to pay compensation to the worker, and referred its dispute to the Tribunal pursuant to s 81A of the Workers Rehabilitation and Compensation Act 1988 (the Act). Essentially the employer disputed that the worker had sustained any injury in compensable circumstances.
4. Where an employer refers to the Tribunal under s 81A of the Act in relation to a worker's claim for compensation the Tribunal is required to determine whether the employer has established that it has a reasonably arguable case in relation to the dispute about liability.
5. The test for whether a reasonably arguable case exists was set out by Evans J in St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90 (St Helens Oysters) at [10]:

The very notion of 'a reasonably arguable case', like the notion of a 'prima facie case' precludes a final determination of a disputed question of fact. On the face of s81A, a reasonably arguable case will exist concerning the liability of an employer to pay a worker if it is reasonably arguable on the material available in relation to the claim or identified deficiencies or weaknesses in the claim that, following a contested hearing it may be rejected.

6. More recently, in Bradshaw v Tasmania Networks Pty Ltd [2020] TASFC 2, Estcourt J set out an alternative formulation of the test, at [17]:

.....what the employer is required to prove is not that there is no liability under s 25 of the Act, but only that there exists, on the evidentiary material the employer relies upon in the s 81A proceedings, a reasonable chance that the worker will be unable to discharge the onus of proof that will ultimately rest with the worker.....on a final hearing of the worker's claim. As [counsel for the employer] put it "the employer was certainly not required in this instance to positively prove that some specific factor other than the worker's employment was the major or most significant contributing factor".

7. The employer's case need not be strong, nor compelling, but it must at least be reasonably arguable: see Vos Construction and Joinery Pty Ltd v Norton-Smith [2016] TASSC 38. The onus of proof, to establish that a reasonably arguable exists, rests with the employer: see, for example, Lamont v MRD Supermarkets Pty Ltd [2016] TASSC 16 (Lamont).

1. In addition to the claim form and initial certificate referred to above, documents relied upon by the employer included reports of Dr Jack Dale, Occupational and Environmental Physician, dated 9 October 2025, 29 October 2025 and 11 November 2025.
2. Dr Dale's report dated 9 October 2025 was authored after he saw the worker for independent medical assessment on 11 September 2025. He took a history from the worker that in early January 2025 she experienced a gradual onset of left forearm weakness and pain located on the dorsum of the wrist. The condition gradually worsened with increase in pain after a working day, especially on days involving a significant number of extractions and cleanings. Lighter days were tolerable. By July 2025 the symptoms had continued to worsen and were impacting her capacity for work. Dr Dale noted that the worker was undertaking light duties.
3. Under the heading 'Assessment' Dr Dale expressed the following opinion:

[The worker] presents with regional neurological symptoms as well as wrist pain symptoms in the left forearm/wrist/hand. Cervical origin or thoracic outlet origin have not been ruled out. Nerve conduction studies would greatly assist with clarification and were performed on 15 September 2025, but I have been advised that a copy cannot be forwarded to me at this time. Therefore, the diagnosis remains unclear but may include radiculopathy, thoracic outlet syndrome, lateral epicondylalgia, nor non-specific forearm pain, median and/or radial neuropathy (including entrapment neuropathies) or a combination of some of these. > > Without having diagnostic clarity, it is difficult to comment on causation. I am therefore left to make assumptions and give an opinion on balance of probabilities, which is not ideal. > > Most of the conditions in the differential diagnosis are idiopathic, degenerative or otherwise not cause by work. Furthermore, the history of a gradual onset and gradual progression is most in keeping with idiopathic, degenerative or systemic causes. Naturally, conditions of insidious onset that reduce tolerances for upper limb use are more likely to be noticed during tasks that require significant upper limb use. In many people this will occur at work. It is therefore common for people to first notice symptoms and their worsening in the workplace. This should not be confused for causation. > > At this stage, there is nothing in the history and examination that points to a work-related disease or injury. However, I would be happy to review my opinion on this once a definitive diagnosis is made or nerve conductions studies become available.

4. Dr Dale was asked about the nature of the worker's injury:

1. An injury which is not a disease;
2. An injury which is a disease;
3. The recurrence, aggravation, acceleration, exacerbation or deterioration of a pre-existing injury or disease; or

A: The condition is most consistent with a disease process of idiopathic degenerative or systemic origin.

1. Dale expressed the view that where there was an uncertain diagnosis, the cause of the worker's condition was unknown but he considered the 'gradual and insidious onset' of the condition meant that it was more likely to be an idiopathic, degenerative or systemic condition rather than one caused by occupational activity.
2. Additional documents were provided to Dr Dale at a later time, including:
   • Nerve conduction report dated 15 September 2025.
   • Patient Health Summary from the worker's general practitioners, printed 27 October 2025.
   • Letter from Jennifer Ball, Physiotherapist, dated 26 October 2025.
   • Left wrist distal intersection injection [notes] dated 27 October 2025.
3. In his report dated 29 October 2025 Dr Dale noted his previous opinion and the differential diagnoses he had identified. He noted he had been provided with a copy of the nerve conduction study dated 15 September 2025 and commented:

I am interested that the history given suggests mainly motor symptoms with some mild intermittent sensory symptoms, whereas the history given to me included sensory and motor symptoms and there were also sensory, motor, reflex and neural tension signs. Regardless of this, the nerve conduction studies were normal, and the neurologist found that weakness on examination could be overcome with encouragement.

There is no electro-physiological evidence of neuropathy. Therefore, the most likely diagnosis is non-specific forearm pain.

He also gave differential diagnoses of lateral epicondylalgia and ganglion cyst related pain. He expressed the view that the worker's condition is a disease which he did not consider to be work-related.

1. Dr Dale's third report, dated 11 November 2025, addressed a clarifying question put to him by the employer's solicitors, as follows:
   1. Do the new materials do anything to alter your opinion in respect to the cause of [the worker's] injury? In particular do you now consider that employment was the major or most significant contributing factor?
   2. It is important when looking at questions of causation to analyse the literature carefully and be aware of important principles. It is common for conditions to be considered by the lay public to be "caused" by something, when the relationship is simply an association. Association is not the same as causation. It is also important to recognise that, in this case, there is more going on that simply what is found (or not found) on imaging or other investigations. Looking at the further material and the totality of the presentation, I do not consider that employment was the major or most significant contributing factor.

1. The employer says that Dr Dale's opinion, as expressed in his three reports when read together, supports a reasonable argument that the worker has not suffered an injury in compensable circumstances; that is the worker has not suffered:

(a) an injury, not being a disease, arising out of or in the course of her employment,

(b) an injury, which is a disease, and to which her employment was the major or most significant contributing factor; or

(c) an injury within the extended definition of that term under s 3 of the Act, that is a recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease where the employment was the major or most significant contributing factor to that recurrence, aggravation, acceleration, exacerbation or deterioration.

1. The employer's position is:
   • Dr Dale was asked to consider each of the recognised kinds of injury under that Act in the question that is set out in [11] above
   • He considered it was most likely that the worker's condition was an injury that is a disease.
   • He considered it was less likely that the disease had been caused by the worker's employment activities, and more likely that it was a disease that was idiopathic, degenerative or systemic.
   • Dr Dale subsequently considered the results of the nerve conduction study.
   • He then considered the most likely diagnosis for the worker's condition was 'non-specific forearm pain'.
   • He maintained his opinion that the worker's condition was a disease that was not likely to be work-related.
   • In response to a specific question, Dr Dale confirmed that it was his opinion that the worker's employment was not the major or most significant contributing factor.
2. The employer referred also to Rural Press Pty Ltd v H. [2022] TASCAT 22 (Rural Press)and submitted that it was a factually similar case to the present case where the parties each relied upon medical evidence that reached different conclusions as to the issues relevant to causation, but the Tribunal accepted the evidence of Dr Ruttenberg (upon who the employer relied) where he drew a distinction between an action that brings out symptomatology of an underlying condition and an action that caused a recurrence, aggravation, acceleration, exacerbation or deterioration.

1. The worker does not submit that it is not open to the Tribunal to find that the employer has established a reasonably arguable case to dispute the claim in relation to the first two grounds of the dispute.
2. However the worker says the employer has not established that there is a reasonably arguable case in relation to the third ground of dispute. The worker says that the employer has failed to establish that there is a reasonable argument to dispute, firstly, that the worker has suffered a recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease that is the 'extended definition' ground, and secondly that the employment was the major or most significant contributing factor to that recurrence etc.
3. The worker says that there is no dispute about the history of injury as given by the worker and no dispute that the worker is suffering from an injury or condition of some kind. The worker says that while there is a difference between Dr Dale and other treatment providers as to the specific diagnosis, Dr Dale in his reports accepts that the worker's symptoms have worsened whilst she has been undertaking her normal duties, and that she undertakes alternative duties to avoid a flare-up in her symptoms.
4. The worker refers to Long v Kmart Australia Ltd [2016] TASSC 6 (Long v Kmart) and particular the discussion by Porter J from [43] onwards in relation to the various aspects of the extended definition of 'injury' in paragraph (b) of the definition in s 3(1) of the Act (noting that it was convenient to use the word 'aggravation' as a shorthand reference to the collective 'recurrence, aggravation, acceleration, exacerbation or deterioration' in the definition).
5. Relevantly to the worker's submissions Porter J noted (citing Federal Broom Company Pty Ltd v Semlitch [1964] HCA 34; (1964 110 CLR 626):

A disease which is progressive according to its nature may by reason of external stimuli have its progress accelerated. Before such acceleration can be found to have caused incapacity there must be more severe or additional symptoms arising from the acceleration which have produced an incapacity which would not otherwise have existed. In this even there is an incapacity caused by an acceleration of the disease. Symptoms in the case of a progressive disease however may only be evidence of the acceleration without producing in themselves any harmful effects, in which event there may be an acceleration of the disease with no present resultant incapacity. > > On the other hand a disease once contracted may be of a chronic type not subject to any progress or any susceptible progress. If external stimuli or the general nature of the disease or both, caused the disease from time to time to produce symptoms which incapacitate then in ordinary language at that time the disease is said to be worse even though the worsening may be temporary only. > > The word 'exacerbate' involves a concept of the heightening of the effect upon an individual as where his sufferings increase. There is an exacerbation of disease with the experience of the disease by the patient is increased or intensified by an increase or intensify of symptoms. The word is directed to the individual and the effect of the disease upon him rather than being concerned with the underlying mechanism.

6. In the present case the worker says Dr Dale's report supports the proposition that the worker's underlying condition is aggravated by her employment where he appears to accept the history given by the worker that her symptoms are increased or intensified by her workplace duties, but not by any actions outside of work.
7. Additionally, the worker said that the employer has not shown any plausible potential alternative cause of the worker's worsening symptoms, other than her employment duties.
8. In support of this submission, the worker relies on St Helens Oysters at [14] where Evans J said:

It is notorious that the genesis for conditions such as stress, anxiety and depression may be multifaceted. The causes may be many and varied and it can be very difficult to identify the most significant causative factor. In the context of litigation, a final determination as to the existence of such a condition and the causative role of any factor, almost invariably turns upon the adjudicator's assessment of the veracity and reliability of the complainant. Accordingly, when a worker claims to suffer from a condition of this nature in circumstances where there are a variety of potential causes for the condition, an employer may show a reasonably arguable case concerning liability by providing evidence of plausible potential causes that are inconsistent with liability.

9. The worker says the employer has here failed to identify any plausible potential cause of the increase of the worker's symptoms, other than her employment duties.
10. The worker also says that Dr Dale's opinion is put without any evidence to support it, and it amounts to no more than a 'bare denial' of the kind that was found to be insufficient to support a reasonably arguable case in Lamont.
11. The worker says Rural Press is distinguishable from the present circumstance, in that Dr Ruttenberg, upon whose report the employer relied in that case, had expressly stated that there was 'no evidence that [the worker] had suffered a recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease'. By contrast, the worker says, Dr Dale makes no reference at all to causation as it relates to a recurrence, aggravation etc.
12. The worker also says that in Rural Press Dr Ruttenberg identified a plausible potential alternative cause of the worker's symptoms, in that he referred to the worker having previously played tennis. The worker says that Dr Dale in the present instance 'expressly stated that no specific external factors are evident that may be impacting on [the worker's condition] and/or recovery' [worker's emphasis].

(1) If in any employment - > > (a) a worker suffers an injury, not being a disease, arising out of or in the course of his employment; or > > (b) a worker suffers an injury, which is a disease and to which his employment contributed to a substantial degree, within the meaning of section 3(2A) - > > his employer is, except as is otherwise provided by this Act, liable to pay compensation in accordance with this Act...

For the purposes of this Act, employment contributed to a disease to a substantial degree only if it is the major or most significant factor

3. "Injury" in the Act is relevantly defined in s 3(1) to include:

(b) the recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease where the employment was the major or most significant contributing factor to that recurrence, aggravation, acceleration, exacerbation or deterioration...

4. In Bradshaw v Tasmania Networks Pty Ltd [2019] TASSC 41_[1]_, Brett J described the circumstances in which an employer may be liable for a claimed injury:

The effect of s 25(1) is that the employer's liability to pay compensation will arise where the worker has suffered an injury as defined, in the circumstances prescribed by that section. In respect of the two pathways to liability created by the section, Pearce J, in Vos Construction & Joinery Pty Ltd v Norton-Smith said at [23]: > > "There is no dichotomy between an injury which is a disease and an injury which is not a disease. A worker is entitled to recover if he or she falls within either head of recovery..." > > The authorities also establish that when regard is had to the extended definition of injury contained in subpar (b), there are in fact three available pathways to liability arising from s 25(1). These are: > > (a) The worker suffers an injury in the primary sense, that is an injury which is not a disease, but is "something that can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state" [2]. Such an injury will be compensable if it arises out of or in the course of the worker's employment. > > (b) The worker suffers a disease to which his employment contributed to a substantial degree within the meaning of s 3(2A), that is, only if it is the major or most significant factor. > > (c) By virtue of the extended definition of injury and its interaction with s 25(1)(b), an aggravation etc of a pre-existing injury or disease is an injury, but only where the employment was the major or most significant contributing factor to that aggravation. In the case of the aggravation of a pre-existing disease, it is the aggravation, not the underlying disease, which must be causally connected to the employment in the required sense [citations omitted].

1. The worker makes no submissions in relation to the first two grounds of dispute. Having regard to the claim documentation, and Dr Dale's opinion as set out in his reports, I am satisfied that the employer has demonstrated there is a reasonably arguable case to dispute liability to pay compensation to the worker in respect of the first two grounds of dispute.
2. That leaves the question of whether the employer has established that there is a reasonably arguable case in respect of the third ground of dispute. If the employer has proved, on the balance of probabilities, that there is a reasonable argument that the worker has not suffered the recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease where the employment was the major or most significant contributing factor to that recurrence, aggravation, acceleration, exacerbation or deterioration, then the referral succeeds.
3. For the sake of brevity (and borrowing from Porter J in Long v Kmart), I will refer to the collective 'substantives' of 'recurrence, aggravation, acceleration, exacerbation and deterioration' simply as 'aggravation'.
4. I will deal first with the worker's submission that the employer has failed to establish the existence of a reasonably arguable case to dispute the worker's claim because it has failed to identify a potential plausible alternative cause of the worker's claimed injury.
5. That submission is misconceived. Whilst an employer may, in accordance with St Helens Oysters, show that there is a reasonably arguable case by providing evidence of a plausible potential cause of injury that is inconsistent with liability, it is by no means a requirement that it must do so to demonstrate that a reasonably arguable case exists.
6. Having said that, Dr Dale has, in fact, identified an alternative cause (or causes) of the worker's claimed injury - in that he identified in his first report that the worker's condition (including the potential diagnosis 'non-specific forearm pain', which was ultimately the conclusive diagnosis) is most consistent with a disease process of idiopathic, degenerative or systemic origin - each of which would be a potential cause that was inconsistent with the employment being the major or most specific contributing factor.
7. I do not accept the worker's submission that Dr Dale's report amounts to no more than a 'bare denial' of the kind referred to in Lamont. In Lamont, the statement of the employer was so lacking in particulars and substance that the Supreme Court determined the Commissioner who heard the s 81A referral:

...was not in a position to understand what the employer's case at a final hearing might be. He was therefore not in a position to evaluate the prospects of the employer's case being successful, or to conclude that there was a reasonable chance of the worker's claim being rejected.

8. The same cannot be said of Dr Dale's opinion as expressed in his three reports. Dr Dale has outlined the history he took from the worker, the diagnosis that he ultimately preferred based on the history and material available to him and his opinion in relation to (amongst other matters) questions regarding causation. The employer's case, as it rests on the opinion of Dr Dale, is sufficiently ascertainable so that it can be assessed to determine whether there is a reasonable prospect of the worker's claim being rejected at a final hearing.
9. Finally, therefore, there are potentially two questions to consider in relation to the employer's third ground of dispute. First, is it reasonably arguable that the worker has not suffered an aggravation of a pre-existing injury or disease? If the answer is in the negative, I then need to consider whether it is reasonably arguable that the worker's employment was not the major or most significant contributing factor to that aggravation.
10. The history given by the worker to Dr Dale was that she had experienced onset of pain from early January 2025, gradually becoming worse, with increasing pain particularly after working days, until the worker's capacity for work was impacted in July 2025. It is this condition, identified in the claim form and initial workers compensation certificate as having commenced in January 2025, for which that claim was made.
11. In the context of the 'pathways to liability', Dr Dale was asked to identify the nature of the worker's injury, as set out at [11] above. His answer - that the worker's condition was 'most consistent with a disease process' - is consistent with him having considered each of the four options put to him before expressing his opinion. His answers to questions thereafter are consistent with his conclusion that the worker's claimed injury is a disease.
12. Although, as the worker has pointed out, Dr Dale accepts the history that the worker is restricted to light duties to avoid an increase in symptoms, Dr Dale addresses this where he notes, as set out above:

...conditions of insidious onset that reduce tolerances for upper limb use are more likely to be noticed during tasks that require significant upper limb use. In many people this will occur at work. It is therefore common for people to first notice symptoms and their worsening in the workplace. This should not be confused for causation.

13. I am satisfied, having regard to the entirety of Dr Dale's evidence, that the employer has established that there is a reasonable argument that the worker's injury is not a recurrence, aggravation, acceleration, exacerbation or deterioration of a pre-existing injury or disease. Because of this conclusion, it is not necessary for me to decide whether there is a reasonable argument that there is no requisite causal connection between the worker's symptoms and her employment.
14. I find that each of the grounds of dispute has been made out, and the employer has a reasonably arguable case to dispute liability to pay compensation to the worker in respect of her claim.
15. The employer, as the conclusion of the s 81A hearing sought an order for costs if the employer's referral was successful. I will hear the parties about costs if that becomes necessary.

Weekly payments of compensation and the cost of benefits payable under Division 2 of Part VI of the Workers Rehabilitation and Compensation Act 1988 are not to be paid by the employer in respect of the worker's claim for compensation from the date of these orders.

[1] Upheld on appeal in Bradshaw v Tasmania Networks Pty Ltd 2020 TASFC 2

[2] See Military Rehabilitation and Compensation Commission v May [2016] HCA 19, 257 CLR 468, as discussed by Pearce J in Vos Construction v Norton-Smith