4. Various other paragraphs follow a similar tone, particularly from [28] onwards.
5. I have difficulty accepting these aspects of Mr Little's statement. I accept that it is common and normal practice for a statement to be prepared by a worker with the assistance of a solicitor, and adopted by a worker. This goes far beyond that. I accept Mr Little's factual history of the background to his work injury and history of development of symptoms. Anything beyond that, including what is understood in medical science, goes beyond Mr Little's expertise and beyond what can reasonably be conveyed in a statement, and I will give no weight to those aspects.

1. Dr Herald provides a number of reports for the applicant. He initially provides a whole person impairment opinion on 12 May 2022, which concerns just the lumbar spine. This report makes no mention of the right knee consequential condition now claimed, other than the following reference:

"His medical history includes multiple problems including gout and a painful right knee and left shoulder."

2. However, this does not attribute the pain in the right knee to the back injury and does not provide any causative pathway. This report was prepared a significant period of time after Mr Little describes the pain coming on in his right knee.
3. Dr Herald provides a further series of reports dated 30 January 2024, which at this point include the right knee as part of the assessment of whole person impairment. Dr Herald takes a history of injury consistent with his earlier report, largely focused on the back, until the final two sentences where the knee is mentioned:

"As a result of the limping, he developed secondary pain in his right knee and an MRI scan was performed in about April 2023 of the right knee. He was diagnosed as having patellofemoral osteoarthritis and a meniscal tear and he was referred to see a knee specialist but that has not been approved either."

4. The diagnosis is set to be "Right knee aggravation of underlying osteoarthritis and medial meniscal tear." Dr Herald then proceeds to assess whole person impairment in the right knee.

1. The respondent relies on two opinions of Dr Wallace, dated 27 March 2023 and 16 September 2024.
2. Consistent with the development of the claim, Dr Wallace's first report makes no mention of the right knee (other than in consideration of referred pain and radiculopathy from the accepted lumbar spine injury). This is in spite of the report being prepared after Mr Little claims the onset of pain.
3. In his second report of 27 March 2023, Dr Wallace notes that Mr Little "now claims that in August 2022, he noted the gradual onset of pain at his right knee without a history of injury. He has undergone no treatment for this condition." Dr Wallace also refers to an X-ray of 10 September 2021 which shows no abnormality, but a large joint effusion.
4. Dr Wallace provides the following causation opinion:

"There is no objective medical evidence that Mr Little suffered any work-related injury at his right knee as a result of the index work incident on 11 April 2017. I note that he did not complain of right knee pain until review with his Local Medical Officer, Dr Lam on 24 August 2022, more than 5 years post-injury. > > There is no known injury mechanism whereby his lumbar spinal condition would lead to a 'consequential' injury at his right knee. > > At the time of review on 4 September 2024, Mr Little denied any previous history of injury at his right knee. However, I note he underwent an X-ray examination of the right knee on 10 September 2021, at which time the clinical history stated; 'Status post twist injury.' This investigation suggests that he sustained a new injury at the right knee at the time of this Xray. > > His current right knee condition is entirely unrelated to his previous work incident on 11 April 2017 and his employment with DPJ Coating Systems Pty Ltd. > > His employment with DPJ Coating Systems Pty Ltd is not a substantial contributing factor to any current right knee condition."

5. I would note that Mr Little does not need to prove that employment was a substantial contributing factor to his right knee condition, but rather that the right knee condition results from his accepted back injury, on the basis of a material contribution.

1. The remainder of the evidence before me is extensive clinical notes from Dr Lam (treating general practitioner), Dr Morsingh (also a general practitioner), Complete Allied Health Care (treating physiotherapists), and Dr Maniam (who provides some handwritten notes that are extremely difficult to decipher).
2. Those records mainly provide evidence of the onset of pain (although the physiotherapy records provide some reference to a cause) and I will refer to some relevant records below under findings and reasons, rather than set them out here.

1. The parties provided oral submissions during the course of the hearing, which were recorded. I will provide a brief summary of the submissions here.
2. The applicant began by referring to whether there was a twisting injury on 10 September 2021, which appears in the report of Dr Wallace and the s 78 notice disputing liability. The applicant submits that there was no twisting injury, as addressed in his statement, and the radiology of 10 September 2021 and X-ray of 28 July 2022 is not before the Commission.
3. The applicant submits that Mr Little developed a limp by reason of his back problem, that was the cause of an aggravation of underlying arthritis and a medial meniscal tear. The applicant then referred to the clinical records reporting a limp, which first appears in a physiotherapists report of 10 July 2020. It was not just a passing observation on one day that there was a problem - this is a constant and serious problem sufficient for the physiotherapist to record it. Dr Lam supports the causation connection.
4. On the question of causation, the applicant submits that it is a commonsense test. There is evidence of a significant limp with an antalgic gait. The whole of the medical evidence assigns it to the back, and the physiotherapist assigns it to limping, with hand holding on the back. Both Drs lam and Herald opine that compensatory movements came from the back and in turn have aggravated an osteoarthritic condition. The applicant doesn't have to establish the whole problem arises from the work injury, only that there is a material contribution.
5. The respondent commenced by pointing out that it is the applicant that bears the onus of proof, and this case runs right up against that challenge. The respondent referred to Murphy v Allity Management Services [2015] NSWWCCPD 49, applying the commonsense test of causation, that is that the injury to the back materially contributed to the condition of the applicant's knee. The respondent submits that I would not do that on the evidence presented.
6. The respondent refers to the opinion of Dr Wallace. He has not disputed that the applicant's knee is trouble, but expressly challenged the link between the applicant's accepted back injury and his knee troubles. Dr Wallace opines there is no known mechanism where a lumbar spine injury would lead to a consequential condition in the right knee. There has to be a mechanism to establish how the causal link comes about.
7. There is a dearth of satisfactory evidence to support the connection. The respondent submits, with reference to South Western Sydney Area Health Service v Edmonds [2007] NSWCA 16 that while the Commission may inform itself, the evidence must be logical and probative. The respondent also submits that, per Hancock v East Coast Timber Products Pty Ltd [2011] NSWCA 11 the expert evidence must be a satisfactory basis to reach its conclusion. This goes to the weight of evidence. The respondent submits that the mechanism of injury is not explained in Dr Herald's report. Whilst he has taken a history of limping and pain, that is not a conclusion. He records the history in a bald way but it's not clear that he's reaching a conclusion. In a case where it is quite explicable that Mr Little might well develop pain in his knee in 2022 simply because of pathology, the applicant has not discharged his onus.
8. It is not the respondent's case that it was a twisting injury but it probably makes no difference to the conclusion.
9. In response, the applicant referred to Dr Herald's opinion submitting that the respondent's submissions ignore the opinion, that there has been a right knee aggravation of underlying osteoarthritis and a medial meniscal tear. The doctor clearly considers that there has been an aggravation, which must be an external cause of some kind other than osteoarthritis.
10. This is compared with the report of Dr Wallace who shows no understanding of what "consequential" might mean, or that a limp can lead to a consequential condition. Dr Wallace has not considered the facts, that there was a limp that predates any "twist" and the X-ray of September 2021 could not be the reason for the problems in the knee. Dr Wallace didn't understand the legal definition of a consequential condition, and there is no cogent line of reasoning that could be read in Dr Wallace's report.

1. As the respondent submits, at the centre of this case is the applicant's onus to prove that he suffered from a consequential condition in his right knee as a result of what is an accepted injury to his back. What the applicant must prove was set out in Moon v Conmah Pty Limited [2009] NSWWCCPD 134:

"It is therefore not necessary for Mr Moon to establish that he suffered an "injury" to his left shoulder within the meaning of that term in section 4 of the 1987 Act. All he has to establish is that the symptoms and restrictions in his left shoulder have resulted from his right shoulder injury."

2. This is a "results from" causation question. This involves a "commonsense evaluation of the casual chain" (Kooragang Cement Pty Ltd v Bates (1994) 35 NSWLR 452). Pathology does not necessarily need to be identified (Trustees of the Roman Catholic Church for the Diocese of Parramatta v Brennan [2016] NSWWCCPD 23 (Brennan)) but that will depend on the issues for determination and the available medical evidence (Grant v Dateline Imports Pty Ltd [2022] NSWPICPD 3 (Grant)). The results from question raised by any consequential condition involves whether the injury materially contributes to the condition identified.
3. It is appropriate to consider the clinical records to show when Mr Little first reported symptoms in his knee. I note, however, that the reporting of symptoms is insufficient to establish what is required from a causal point of view.
4. On 24 August 2022, Dr Lam provides a comprehensive clinical note that includes the following:

"- Now has also suffered secondary knee ?meniscal injury > > - Worsening R knee pain > > - Physio is of the opinion that knee injury is secondary to back"

5. This is the first record from any doctor of any problem in the knee. At this point Dr Lam recommended an MRI of the right knee. There was some confusion regarding approval of this MRI from the insurer, and tardiness in attending for imaging, which eventually proceeded in April 2023.
6. Aside from the clinical records, there are a number of referrals from Dr Lam contained in the evidence. On 30 April 2024, she writes a referral letter to Dr Hoe including the following:

"He had a work accident in 2017 - lifted a heavy item and injured his lower back. Over time, due to compensation, he developed increasing knee pain. > > A recent MRI shows tricompartmental and meniscal pathology."

7. A short time later, on 29 May 2024, Dr Lam referred Mr Little for physiotherapy, with the following included in the letter:

"He had a work accident in 2017 - lifted a heavy item and injured his lower back. Over time, due to compensation, he developed increasing right knee pain and now also increasing bilateral lower limb and feet pain. He is seeing an orthopaedic specialist for the right knee, but would benefit from physio to improve his mobility."

8. These two reports are the highest Dr Lam takes the issue in support of a causal connection - that over time, due to compensation, Mr Little developed increasing knee pain.
9. Mr Little attended physiotherapy over many years, for treatment to the back as well as an unrelated shoulder issue. A physiotherapy initial report, dated 10 July 2020, provides a summary of initial assessment findings, for "severe lumbar spine symptoms". There is an observation of "increased BMI, limping gait with left hand supporting on back, slow movement". No comment is made in respect of the knee and the "impression" does not mention it. The clinical record of 3 July 2020 (the attendance on which the report is prepared) contains the following: "pt c/o compensatory movement of right leg, so c/o right knee pain. he also c/o groin pain."
10. This report appears to be the first reference to Mr Little limping. The observation recorded about limping with hand supporting on back then continues to appear in the physiotherapy clinical records under "objective" (that is, objective findings as opposed to Mr Little's subjective reports). By 28 June 2022, the records began to reference ankle pain, which, based on radiology, showed arthritic changes. Mr Little's ankles do not form part of the present claim.
11. On 4 November 2022, there is reference to an objective observation of "antalgic gait".
12. The first reference that I could find within the physiotherapy clinical records to knee pain (as opposed to a limp or an antalgic gait) appear on 20 January 2023. Oscar Lam records a subjective history of "Reported ongoing (R) knee pain due to compensatory movements". This subjective history continues in the clinical records for a period in 2023 (until 17 March 2023).
13. The radiological evidence in this case is scattered, and at times simply missing. There is an X-ray dated 11 June 2024 with a clinical history of "severe meniscal tearing after motor vehicle accident". It is noted, however, that it is not the respondent's case that this was the cause of Mr Little's symptoms, but rather he has not proved on the balance of probabilities that his knee condition results from his lumbar spine injury.
14. Also missing are records or reports from treating pain specialists, which may have shed some light on what, if any complaints were made about the knee as part of that treatment regime.
15. Dr Herald refers to an X-ray of the right knee that occurred on 28 July 2022, with a described result of "prominent post-traumatic bursitis or synovitis". Dr Wallace refers to an X-ray of the right knee dated 10 September 2021, with a history of "Status post twist injury". Again, the respondent is not alleging this is the cause of Mr Little's symptoms or a separate injury. There is also reference to an "US on right knee" in a record of 16 March 2021, which is presumably an ultrasound. This is also not before me or mentioned in the medicolegal opinions.
16. The issue with the above is not the conflicting potential causes of Mr Little's problems in his right knee. It is the fact that the above records are entirely absent from the material before me. Further and on that basis, whether any of the medical specialists who have provided opinions in this case have had access to the full gamut of relevant materials in Mr Little's case. In circumstances where the applicant has the onus to prove his claim, this weighs against any finding I can make in his favour. It is not clear to me what investigations Mr Little has undertaken, what they show in terms of pathology in the knee, and how that, from a causal perspective through a medical opinion, supports a connection with Mr Little's accepted lumbar spine injury.
17. The applicant's submissions put much weight on the existence of a limp and/or an antalgic gait (if they are of any real difference). I accept there are repeated references to that, largely throughout the clinical notes. It appears that since about 2020, Mr Little has walked with a limp. This is mostly consistent with Mr Little's statement that "the fact that I was limping in 2020 is documented".
18. However, Mr Little goes on to state that "and is directly attributable to the ongoing back injury and left leg weakness". I do not accept that this is documented in the clinical material. This is a causation explanation that is absent. The only reference to knee pain is in the clinical record of Mr Little's attendance on 3 July 2020. By 24 November 2020 there is reference to complaints of "knee swelling with severe knee pain" and a restriction of standing and walking for 10 minutes due to complaints of "right knee pain".
19. We have then some oblique reference to knee pain (without specific treatment of that issue) and a limp of some kind. What is missing from all of this is an explanation of how that translates, in a "results from" sense, into a consequential condition.

Dr Herald takes a history of limping (noting that the following appears under the heading "history of alleged injury", and thus does not form part of Dr Herald's opinion or conclusion):

"As a result of the limping, he developed secondary pain in his right knee and an MRI scan was performed in about April 2023 of the right knee. He was diagnosed as having patellofemoral osteoarthritis and a meniscal tear and he was referred to see a knee specialist but that has not been approved either."

20. The applicant refers to this passage, read in conjunction with this sentence (under the heading of assessment): "Right knee aggravation of underlying osteoarthritis and medial meniscal tear" as supporting of a causal connection. The accepted principle is one of a commonsense chain. What is missing between the clinical material before me, summarised above, the conclusion of Dr Herald (putting aside the issues around the radiology which I have discussed), and an actual explanation of how an altered gait or limp could lead to a consequential condition. Dr Lam's referral, which state that "over time, due to compensation, he developed increasing knee pain" is similarly devoid of explanation.
21. In my view Dr Herald's opinion proceeds on a basis of assumptions without explanation, that is that Mr Little limped, and therefore has a consequential condition. He refers to radiology showing patellofemoral arthritis and a meniscal tear. Has this pathology been caused by a limp? Dr Herald does not explain if that is the case, nor go a step further (and a necessary step, in my view) and explain how.
22. Dr Wallace's opinion does not take this much further, noting that at the time of examination Mr Little had no limp or a possible attribution to a twist injury (that is unconfirmed). However, this is not necessary as the applicant must prove his case.
23. The "commonsense chain" is an accepted part of the law in NSW. Consequential conditions can arise from injuries on a commonsense basis. Pathology may not need to be identified in all cases (Brennan), but in certain circumstances is necessary (Grant). It is not enough, in my view, to proceed on the existence of the commonsense chain without explaining how that chain operates. The opinion of

Dr Herald is so scant on that explanation as to be unacceptable. On the other hand, Dr Wallace's ultimate conclusion on the causation question is this:

"There is no known injury mechanism whereby his lumbar spinal condition would lead to a 'consequential' injury at his right knee."

24. It may be that there is a mechanism by which the lumbar spine condition suffered by Mr Little could lead to a consequential injury in the right knee. The issue is that this is not explained in the medical evidence.
25. I am not satisfied, on the balance of probabilities, that the applicant has proved his case that he has a consequential condition in his right knee resulting from his accepted back injury.
26. Accordingly, I will make an award for the respondent in respect of that body part and refer the lumbar spine for an assessment of impairment.