News

At Work But Not Because of Work

Written by Harman Kaur | Sep 10, 2026, 5:19:18 AM
Key takeaways
  1. For an aggravation of a pre-existing degenerative condition to be compensable under s4(b)(ii) of the Workers Compensation Act 1987 (1987 Act), the worker must prove that employment was the main contributing factor to the aggravation itself, not merely that symptoms first appeared at work.
  2. Contemporaneous records, incident reports and CCTV footage can be decisive where video evidence does not support the mechanism of injury relied on by the worker’s treating and medico-legal experts.

Brief facts

The worker was employed by Penrith Rugby League Club Ltd. She alleged that on 19 March 2025 she sustained an aggravation of pre-existing degenerative changes to her right knee in the course of her employment. 


There was no dispute that the worker had significant pre-existing issues in her right knee.
The worker’s evidence was that, while walking around a white picket fence barricade near reception on 19 March 2025, she felt a tearing sensation and heard a noise in her right knee. She experienced immediate severe pain and told colleagues she had twisted her knee, having not previously experienced any similar symptoms. The employer disputed injury and relied on incident reports and, in particular, CCTV footage.


The worker’s treating surgeon and qualified orthopaedic specialist opined that she had sustained a work-related meniscal injury based on a history of a twisting incident. The employer’s qualified orthopaedic surgeon considered the incident at work trivial and that the underlying degenerative meniscal tear would have become symptomatic irrespective of employment. 


The issues in dispute were whether the worker sustained an injury for which employment was the main contributing factor (s4), whether employment was a substantial contributing factor (s9A), and whether the claimed surgery and rehabilitation were reasonably necessary as a result of that injury (s60).


Decision

Member John Turner made an award for the employer in respect of both the alleged right knee injury on 19 March 2025 and the claim under s60 of the 1987 Act for the costs of the right knee arthroscopy surgery and associated rehabilitation. 


Applying Kooragang Cement Pty Ltd v Bates, Taylor v J & D Stephens Pty Ltd [2018] NSWCA 287 and Deputy President Snell’s decision in AV v AW [2020] NSWWCCPD 9, the Member confirmed that a disease injury under s4(b)(ii) requires three components: a disease, an aggravation in the course of employment, and employment as the main contributing factor to that aggravation. The Member further confirmed that the test is one of causation, to be determined on the whole of the evidence, considering competing work and non-work causal factors.


On the CCTV footage, the Member accepted that the worker sustained an incident injuring her right knee on 19 March 2025 as she walked past a brochure stand near reception, but not in the twisting motion around a barricade she described. 


The Member held that the mere fact the incident occurred at work was insufficient to satisfy the ‘main contributing factor’ test in s4(b)(ii), particularly where the ultrasound and X-ray performed on the day of incident showed only degenerative change and no meniscal tear was identified until an MRI on 22 April 2025. 


Accordingly, the Member held that no compensable injury was established and entered an award for the employer.


Implications

This decision is a useful reminder that establishing an injury in the course of employment is only the starting point in a claim involving an aggravation of pre-existing degenerative disease. 


Where medical evidence indicates that a degenerative condition would have become symptomatic in any event, and the mechanism of injury described by the worker is not supported by contemporaneous records or CCTV, insurers may be able to successfully resist liability.