DETERMINATION OF APPEAL PANEL	
	
CITATION:	Perrin v Toowoomba Building & Construction Pty Ltd [2024] NSWPICMP 118	
		
APPELLANT:	Christopher Stephen Perrin 	
		
RESPONDENT:	Toowoomba Building & Construction Pty Ltd	
		
Appeal Panel		
		
MEMBER:	John Wynyard	
		
MEDICAL ASSESSOR:	Brian Stephenson	
		
MEDICAL ASSESSOR:	Chris Oates	
		
DATE OF DECISION:	5 March 2024	
		
CATCHWORDS: 	wORKERS cOMPENSATION - Workplace Injury Management and Workers Compensation Act 1998; appeal from 14% finding regarding injury to lumbar spine; whether Medical Assessor (MA) erred in his assessment of ADL entitlement under chapter 4.35 of the Guides; whether MA erred in application of section 323; Held – chapters 4.33 - 4.35 do not set out criteria, as wide discretion given; reasons given at [11] of the Medical Assessment Certificate (MAC) to be seen in context; observations on the utility of template at [11]; Cole v Wenaline Pty Ltd considered and applied; MAC confirmed.

BACKGROUND TO THE APPLICATION TO APPEAL
1.	On 26 October 2023 Christopher Stephen Perrin, the appellant lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Murray Hyde-Page, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 4 October 2023.
2.	The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act): 
•	the assessment was made on the basis of incorrect criteria, and
•	the MAC contains a demonstrable error.
3.	The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the ground(s) of appeal on which the appeal is made. 
4.	Rule 128 of the Personal Injury Commission Rules 2021 (the PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules.
5.	The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed 
1 March 2021 (the Guides) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5). “WPI” is reference to whole person impairment.
RELEVANT FACTUAL BACKGROUND
6.	On 3 October 2023 an amended referral was made to the Medical Assessor for an assessment of WPI caused by injury to the lumbar spine and scarring – TEMSKI, which occurred on a deemed date of 22 March 2023.
7.	Mr Perrin was employed as a labourer by the respondent, with whom he commenced at the beginning of February 2022. He had been there for about two weeks when he developed some low back pain. 
8.	On 22 February 2022 whilst lifting a heavy concrete block, he developed severe low back pain and shooting pain down his right leg into his foot. He ceased work as a result. 
9.	He contacted his general practitioner (GP) on 25 February 2022 and on 27 February 2022 was taken by ambulance to the emergency department of the Manning Base Hospital. 
10.	He was found to have developed a right foot drop after CT and MRI scans had been taken. He was transferred by ambulance to John Hunter Hospital as a matter of urgency.  
11.	On 1 March 2022 he underwent a right L3/4 discectomy with neurosurgeon Dr Ng.  He remained at John Hunter Hospital for a few more days and was eventually discharged home.
12.	Subsequently he attended the outpatient unit at Forster Private Hospital under the care of his rehabilitation physician, Dr Vivek Gupta, and has continued with rehabilitation treatment. 
13.	As time has gone by he has regained strength in his right foot and the foot drop has shown significant improvement. 
14.	The Medical Assessor assessed a 15% WPI in respect of the injury to the lumbar spine, from which he deducted 1/10th leaving 14% WPI.  He found no WPI regarding the scarring.
PRELIMINARY REVIEW
15.	The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.
16.	Mr Perrin requested a re-examination but as no error was found such a re-examination was not necessary.
EVIDENCE
Documentary evidence
17.	The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.  
Medical Assessment Certificate
18.	The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out, where relevant, in the body of this decision. 
SUBMISSIONS 
19.	Both parties made written submissions which have been considered by the Appeal Panel. 
FINDINGS AND REASONS 
20.	The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made. 
21.	In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
22.	The appellant alleged that the Medical Assessor erred in assessing Mr Perrin’s restrictions in the activities of daily living (ADL), and in finding that Mr Perrin’s pre-existing condition contributed to the impairment caused by the subject injury.
The MAC
23.	The Medical Assessor noted Mr Perrin’s work history.  He said:
“He worked in IT for eight or ten years. He has done bricklaying and labouring for a year. He worked as a storeman and forklift driver for about a year.
He was on Centrelink payments for about five years when he had a drug problem.
Prior to his work injury in February 2022, he had not worked for six months and before that, he had done some light landscaping work, which mainly involved lawn mowing.”
24.	The Medical Assessor recorded the following regarding Mr Perrin’s social activities and ADL:
“Social activities/ADL: Chris Perrin is 41 years of age, single and living on his own in a small unit. Around the corner are his parents, who care for his three children aged 14, 11 and 2 years. He states that his older children help him with some heavier indoor domestic tasks. He is able to do all his own personal care without any assistance. He has restriction on outdoor activities and cannot play sport and does not drive. He is able to walk to the shops and do small amounts of shopping two or three days a week.”
25.	The Medical Assessor summarised his findings as to injury and diagnosis. He said:
“In summary, Christopher Perrin, who is 41 years of age, suffered an acute low back strain on the 22 February 2022 lifting a concrete block at work. He appears to have developed an acute right L3/4 disc protrusion, a right footdrop and sensory changes. He needed urgent surgery, and this was performed at John Hunter Hospital on the 1 March 2022, when he had an L3/4 discectomy.”
26.	In explaining his calculations at [10b] of the MAC, the Medical Assessor said:
“With reference to WorkCover Guides page 29 Paragraph 4.37, it states that operations with surgical decompression are considered under DRE Category III. With reference to AMA Guides 5th Edition page 384 Table 15-3, this gives a range of WPI of 10% to 13%. With the effect on his activities of daily living he can do all his own personal care and hygiene. However, he does need assistance with indoor and outdoor domestic tasks. When this is taken into account, there is therefore 2% WPI for ADLs. When this is added to 10%, he therefore has 12% WPI.
As is noted on page 29 of WorkCover Guides, using Table 4.2 there is a further 3% WPI for ongoing radiculopathy. This is combined with 12%, to give 15% WPI.
I need to take into account that he had evidence of moderate to severe generalised
degenerative disc disease of the lumbar spine of a longstanding nature. He states that this had not previously been symptomatic prior to his work injury. I consider one tenth the level of WPI is due to this pre-existent degen[e]rative condition. One tenth of 15% is 1.5%. When this is subtracted he has 13.5%, which rounds up to 14% WPI.
This pre-existent degenerative condition of the lumbar spine does directly contribute to his whole person impairment.”
27.	The Medical Assessor considered the opinions of the treating and qualified medical practitioners at [10c]:
“Overall, I consider both Dr Hopcroft and Dr Poplawski have made errors in their calculations. The calculation from Dr Hopcroft came to the conclusion of 14% WPI. 
Dr Poplawski has over calculated the level of WPI in the lumbar spine to 19%, he has also given a further 1% WPI for effect of activities of daily living, which I do not agree with as Mr Perrin can live independently on his own and do all personal care…..”
28.	With regard to the question of a deduction for any pre-existing condition, we reproduce the relevant templated paragraph [11] which contain the Medical Assessor’s comments:
“11. DEDUCTION (IF ANY) FOR THE PROPORTION OF THE IMPAIRMENT THAT IS DUE TO PREVIOUS INJURY OR PRE-EXISTING CONDITION OR ABNORMALITY 
a. In my opinion the worker suffers from the following relevant previous injuries, pre-existing conditions or abnormalities: 
(i) He suffers from moderate to severe generalised degenerative disc disease of the lumbar spine that has also affected the L3/4 level. 
b. The previous injury, pre-existing condition or abnormality directly contributes to the following matters that were taken into account when assessing the whole person impairment that results from the injury, being the matters taken into account in 10a, and in the following ways: 
(i) I have concluded that this pre-existent degenerative disc disease has had a significant effect on the severity of the symptoms in his back and right leg following his acute work injury on the 22 February 2022, when he suffered the acute L3/4 disc protrusion. 
c. The extent of the deduction is difficult or costly to determine so in applying the provisions of s.323(2) I assess the deductible proportion as one tenth. (can only be used when not at odds with available evidence)”

SUBMISSIONS
Appellant’s submissions
Activities of daily living 
29.	The first ground was that the Medical Assessor had applied incorrect criteria in his assessment of the effect of Mr Perrin’s injury on his ADLs pursuant to Chapters 4.33 - 4.35 of the Guides.  
30.	Mr Perrin acknowledged that the Medical Assessor had assessed 2% WPI and that he had explained why he did not find a 3% WPI.  However, it was submitted that in doing so the Medical Assessor had applied incorrect criteria.
31.	The criteria set out by Chapter 4.35 required, when assessing the 3% category, only a finding that the worker’s capacity had been “affected,” it was argued. The Medical Assessor had erred because he applied a stricter test of whether the worker was unable to undertake the activities therein described. 
32.	Mr Perrin submitted that the word “affected” could be defined as “to be influenced or impaired by an external factor”.  This, it was argued, was a lower threshold than that applied by the Medical Assessor. We were referred to Mr Perrin’s statement of 28 July 2023, which reported a number of subjective complaints by Mr Perrin as to his limitations. 
33.	 This, it was submitted, constituted evidence that Mr Perrin’s capacity to undertake person care activities such as dressing, washing, toileting and shaving had been “affected”.
Section 323 
34.	The second ground was that the Medical Assessor erred in his application of the provisions of s 323 of the 1998 Act. 
35.	We were referred to a number of uncontroversial decisions regarding the application of this section.   It was submitted that the findings by the Medical Assessor were “inconsistent,” “unexplained,” “a lacuna in his reasoning,” and that they did “not make sense.” 
36.	Mr Perrin said that the Medical Assessor did not opine that the pre-existing degenerative changes contributed to the subject injury, i.e. the L3/4 disc protrusion, but preferred to diagnose the injury as “acute”. Further, Mr Perrin submitted that the Medical Assessor did not refer to any radiological investigations that would confirm such a description. In the absence of any evidence as to the radiological condition prior to the injury, it was submitted that “it is impossible and indeed improper to conclude that the pre-existing reporting of back pain was at the relevant L3/4 level”.
37.	It was submitted that “acute” conditions were “severe and sudden in onset.”  Mr Perrin contrasted an acute condition with a chronic condition, the latter being a “long- developing syndrome.”
38.	Mr Perrin submitted that there was a lack of pre-existing radiological investigations, minimal pre-existing complaints of back pain, and evidence that he had been able to work in physically demanding labour for many years prior to the injury. The Medical Assessor had erred, it was submitted, as he had not reconciled that evidence with an explanation as to how and to what extent the asymptomatic pre-existing pathology had contributed to the subject injury, which had manifested acutely and subsequent to the L3/4 disc protrusion.  Mr Perrin submitted further that the Medical Assessor had conceded that the injury was “specific and new,” and was caused by the “new pathology” caused by the subject injury.
39.	 Mr Perrin argued that there was no evidence of any pre-existing condition existing which contributed to the need for the lumbar spine surgery, in contrast with the “subject injurious event” that had aggravated any “dormant pre-existing degenerative changes.” 
40.	Mr Perrin referred to the opinion of “Dr Andrew Porteous,” who noted prior complaints of backache but nonetheless made no s 323 deduction.  Mr Perrin said that therefore it was not the degeneration in his lower back but the injurious event that caused the L3/4 protrusion which in turn required surgery.  It was not, Mr Perrin said, “an organic process.”  
41.	 Mr Perrin submitted that “the mechanism of the injurious event was of a specific and unique intensity.”  He argued that but for the injurious event, he would not have required surgery.   
42.	 We were referred to other Medical Panel decisions.
43.	We were further referred to another authority, Fire & Rescue NSW v Clinen.  It was submitted, uncontroversially, that an assumption would not suffice as a basis for making a s 323 deduction. 
44.	It followed therefore, Mr Perrin argued, that the Medical Assessor had applied incorrect criteria in making a 1/10th deduction pursuant to s 323.  The correct application of that section would not have resulted in any deduction.  
45.	A demonstrable error had also been made, it was submitted as the Medical Assessor had failed to give adequate reasons.  We were referred to Western Sydney Local Health District v Chan in which Adams J confirmed (as have a number of other authorities) that a Medical Assessor is bound by the dicta in Wingfoot Australia Pty Ltd v Kocak.
Respondent’s submissions
Activities of daily living 
46.	With regard to the first ground of the appeal, the respondent submitted that the Medical Assessor did not find that Mr Perrin’s ability to undertake his own personal care was “affected,” referring us to the comments made by the Medical Assessor.     
47.	We were further referred to the terms of Chapter 4.33 of the Guides, which specifically prohibited an assessment being made solely on a self-report.  The Medical Assessor accordingly made no error, the respondent submitted, as he had used his clinical judgment and had regard to all of the relevant material.
Section 323
48.	As to the submissions regarding the application of s 323, we were referred to the findings by the Medical Assessor. It was submitted that the statutory 1/10th deduction was not at odds with the evidence and ought to be confirmed.  The respondent relied on the leading case of Cole v Wenaline Pty Ltd, and Vitaz in that regard.
49.	The respondent also submitted that the reasons given by the Medical Assessor were adequate and satisfy the test in Wingfoot. 
DISCUSSION
Activities of daily living 
50.	The relevant paragraphs of the Guides which relate to the assessment of additional WPI to the base impairment commenced at Chapter 4.33:
“4.33 Impact of ADL. Tables 15-3, 15-4 and 15-5 of AMA5 give an impairment range for DREs II to V. Within the range, 0%, 1%, 2% or 3% WPI may be assessed using paragraphs 4.34 and 4.35 below. An assessment of the effect of the injury on ADL is not solely dependent on self-reporting, but is an assessment based on all clinical findings and other reports.”
51.	Chapter 4.34 contains a diagram regarding the categories available as described in Chapter 4.35.  It also states:
“The following diagram should be used as a guide to determine whether 0%, 1%, 2% or 3% WPI should be added to the bottom of the appropriate impairment range…..”
(As written).
52.	Chapter 4.35 provides:
4.35 Increase base impairment by: 
• 3% WPI if the worker’s capacity to undertake personal care activities such as dressing, washing, toileting and shaving has been affected 
• 2% WPI if the worker can manage personal care, but is restricted with usual household tasks, such as cooking, vacuuming and making beds, or tasks of equal magnitude, such as shopping, climbing stairs or walking reasonable distances
• 1% WPI for those able to cope with the above, but unable to get back to previous sporting or recreational activities, such as gardening, running and active hobbies etc.”
53.	A perusal of these guidelines demonstrates that a Medical Assessor has considerable  discretion in his determination. We do not read the language of Chapter 4.35 as being intended as strict criteria, but as examples of matters to be considered in determining the appropriate modification.  The instruction in Chapter 4.34 that the diagram (which illustrated in geometric form the three categories described in Chapter 4.35) be used as a guide, and the further requirement in Chapter 4.33 that the assessment not be based solely on the worker’s self-report but include clinical findings and other reports, are all indications that these guidelines are not to be viewed as strict criteria.  
54.	Seen in this light, it is immaterial whether a Medical Assessor expressed his opinion in the exact terms of the guideline. The Medical Assessor said, as we have noted above, that Mr Perrin was “able to do all his own personal care without any assistance,” “can live independently on his own and do all personal care” and “he can do all his own personal care and hygiene.”  
55.	Further, the prohibition contained in Chapter 4.33 makes it plain that a Medical Assessor is not to base his opinion solely on self-reporting.  Mr Perrin reproduced portions of his statement, but the Medical Assessor was required to accept them in the light of his clinical judgement – indeed he was specifically required not to solely depend on self-reporting.   In Ferguson v State of New South Wales Campbell J said at [23]:

“By reference to NSW Police Force v Daniel Wark [2012] NSWWCCMA 36, the Appeal Panel directed itself that in questions of classification under the PIRS:
‘… the pre-eminence of the clinical observations cannot be underrated. The judgment as to the significance or otherwise of the matters raised in the consultation is very much a matter for assessment by the clinician with the responsibility of conducting his/her enquiries with the applicant face to face’.”
56.	We accordingly decline to accept Mr Perrin’s submissions, which were based on a somewhat more literal approach to the wording of the relevant bullet point.  
Section 323 
57.	Section 323 of the 1998 Act provides relevantly:
“(1) 	In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality.
(2) 	If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence.”
58.	Mr Perrin argued that the Medical Assessor was required to opine that the pre-existing degenerative changes had contributed to the L3/4 disc protrusion, but that it was impossible for him to do so in the absence of prior radiological evidence, and his finding had thus been both “impossible” and “improper.”   There are a number of difficulties with this submission.
59.	Mr Perrin’s assertion that he had been able to work in physically demanding labour for many years prior to the injury was not, with respect, born out by the evidence. As indicated above, the history taken was that Mr Perrin had been working in IT for 8 or 10 years, that he had worked as a brick layer and labourer for one year, and as a storeman and forklift driver for another year. He had been on Centrelink payments for about five years, and was doing light landscaping work which mainly involved lawnmowing in the job before he commenced with the respondent. He had been off work for six months when he commenced with the respondent in early February 2022 and suffered his injury on 22 February 2022.  
60.	That history does not support Mr Perrin’s submission as to his past work history.   To the contrary, he had not been working at all for the six months immediately prior to his commencement with the respondent, and before that he had mainly been doing lawnmowing. This history was not challenged by Mr Perrin – indeed he did not mention his past history at all in his statement. 
61.	The history of the injury itself was that as he was doing his work he began to feel low back pain, which culminated on 22 February 2022 when he was apparently lifting a heavy concrete block, estimated to the Medical Assessor at 100kg, and in Mr Perrin’s statement at 80kg.  Dr Poplawski also took a history that in the process of carrying out his activities 
Mr Perrin developed lower back discomfort, until his symptoms became severe enough that he had to give it up altogether.  
62.	The diagnosis by the Medical Assessor was the same as that reached by the qualified experts, namely an acute right L3/4 disc protrusion and right footdrop with sensory changes. Dr Poplawski found a disc prolapse at the L3/4 level, and Dr Hopcroft diagnosed an acute onset L3/4 intervertebral disc protrusion.  
63.	In Cole Schmidt J said, in an oft cited passage:
“38 What s 323 required…. was that the evidence be considered, so that it could be determined, firstly, what the level of impairment after the second injury was. Secondly, whether a proportion of that impairment was due to the first injury. Thirdly, what that proportion was. Undoubtedly in undertaking this exercise, the medical members of an Appeal Panel must utilise their medical judgement, knowledge and experience. Nevertheless, all stages of the statutory exercise must be undertaken in the light of the evidence and without the making of assumptions not provided for by the section.”
64.	The facts in Cole were that the worker had suffered a back injury in 1976 for which he had undergone surgery, and from which he had a good result. That was the “first injury” referred to by her Honour. The second injury occurred in 2005, which also resulted in surgery in 2008.   The Medical Assessor (“AMS” as they were then called) reduced the WPI found from the second injury by half pursuant to s 323 on an assumption that “irrespective of outcome” the first injury resulted in an impairment which must have contributed to the impairment caused by the second injury.  Her Honour rejected that approach, saying at [36]:
“36 In this case the difficulty, it seems to me, is that the majority proceeded on the basis of an assumption as to what will be the situation in every case where an earlier injury to the spine has occurred, ‘irrespective of outcome’; rather than focussing on the evidence of what the outcome in fact was, after the earlier injury and determining how that contributed to the impairment present after the second injury. That required an assessment of the evidence ….. That assessment was not undertaken.”

65.	There has been no appeal against the level of impairment assessed by the Medical Assessor with regard to the subject injury, which was the first step identified by Schmidt J in calculating whether and to what extent a deduction pursuant to s323 was required. The second step requires the utilisation of medical judgement, knowledge and experience, in the light of the evidence, in determining whether a proportion of the level of impairment was due to 
Mr Perrin’s pre-existing condition. It is necessary therefore to consider the evidence.
66.	In the present case the radiological evidence showed that Mr Perrin’s lumbar spine  was affected by degeneration.   The CT scan of 28 February 2022 demonstrated “ generalised degenerative disc disease of the lumbar spine.  There were disc protrusions also at these other lumbar levels”.  The MRI scan of the same date showed “multilevel disc bulges and protrusions. In particular, there was a large L3/4 disc protrusion extending superiorly in a subligamentous fashion…..A disc bulge at L4/5 level was impinging on the adjacent L5  nerves”. 
67.	The Medical Assessor, as indicated, at [11a (i)] of the template found Mr Perrin to be suffering from a “moderate to severe generalised degenerative disc disease of the lumbar spine that has also affected the L3/4 level”.  At [11b(i)] the Medical Assessor’s conclusion that the “pre-existing degenerative disc disease had a significant effect on the severity of the symptoms in his back and right leg following his acute work injury… when he suffered the acute L3/4 disc protrusion” must be seen in context.
68.	Whilst the Medical Assessor might have perhaps expressed himself a little more clearly at [11b(i)], we reject Mr Perrin’s attempt to portray that opinion as being internally inconsistent.  We have reproduced the entire template for [11] of the MAC, and it can be seen that the templated questions, particularly [11b], are somewhat difficult to decipher.  However any ambiguity in the Medical Assessor’s response to that question is resolved when seen in the context of his description of the relevant pre-existing condition in [11a(i)].  He there identified the severe generalised degenerative disc disease as being the relevant pre-existing condition.  That is apparent from the reports of the above radiological studies which demonstrated that the pre-existing degenerative disc disease was associated with other disc protrusions at other lumbar levels – particularly at L4/5.  
69.	Further, the Medical Assessor, when explaining his calculations at [10b] made it quite clear that the moderate to severe generalised degenerative disc disease was of long standing, and that it directly contributed to Mr Perrin’s whole person impairment.
70.	Although the Medical Assessor noted that Mr Perrin had not previously been symptomatic prior to his injury, a history also recorded by Dr Alan Hopcroft, who reported to the respondent on 5 June 2023,  Dr Poplawski in his report of 10 January 2023 noted:
“some chronic back ache on occasions in August 2019 which however was intermittent and did not cause him any significant issues and did not prevent him from working.”
71.	It is also relevant that, contrary to Mr Perrin’s submissions, his injury was not “..sudden in onset.”   The history taken by the medical experts and the Medical Assessor was that 
Mr Perrin started to get some low back pain after he had been working for the respondent – prior to the incident on 22 February 2022.  Mr Perrin himself said:
“22. After repeatedly performing my duties, I began to notice some pain and symptoms develop in my lower back.
23. More specifically, the pain and symptoms in my lower back were an ongoing thing
and it started almost straight away. When I was lifting these heavy panels, I noticed
soreness in my back because of the work.
24. This continued up until about 22 February 2022.”
72.	This description is consistent with the previously asymptomatic degenerative condition becoming symptomatic as Mr Perrin was performing his duties with the respondent, and is further evidence that his pre-existing condition was contributing to the destabilisation of his lumbar spine, which culminated in the L3/4 disc protrusion.   
73.	We are accordingly satisfied that a proportion of the WPI found by the Medical Assessor in relation to the subject injury was indeed contributed to by Mr Perrin’s pre-existing condition.
74.	The third step is to determine what that proportion should be. The Medical Assessor’s determination was that it should be 1/10th, again using the templated form of [11c].  For the reasons given above, we find that assessment to be appropriate and open to him on the evidence.  It was consistent with the available evidence.
75.	It was submitted that the reasons given by the Medical Assessor were inadequate with regard to both the challenge to his assessment of the modifier pursuant to Chapter 4.35 of the Guides and his assessment in applying the provisions of s 323.
76.	These grounds, in the light of our above reasons, are no longer relevant.  We are satisfied that the Medical Assessor gave adequate reasons in relation to both challenges, and we have alluded to additional evidence with regard to s 323.  As we indicated, the form of [11] of the MAC template can tend to confuse and perhaps should be amended. In any event the MAC should be confirmed. 
77.	For these reasons, the Appeal Panel has determined that the MAC issued on 
4 October 2023 should be confirmed.