Decisions of the High Court
7 The use of the concept of whole person impairment in the Guide to assess the degree of impairment arising from a particular injury has caused confusion. The High Court has emphasised that the Guide must be used in a way which conforms to the statutory requirements arising from the SRC Act itself. In Canute v Comcare (2006) 226 CLR 535 ("Canute"), the Court said (at [37]):
…The Act only adopts the "whole person impairment" approach with respect to permanent impairments resulting from each "injury". That "whole person" approach cannot properly be used to deny the applicability of s 24 to something which corresponds to the legislative definition of an "injury". The statutory criterion of an "injury" is antecedent to the concept of "whole person" impairment, not the other way around.
8 The result of this approach is that compensation must be assessed for individual injuries. Although, under the Guide, the consequences of each injury must be determined by reference to the notion of whole person impairment and be stated as a percentage, that percentage determination only relates to the permanent impairment arising from that injury, which is to be assessed individually, regardless of the position with respect to other injuries or the compensation which may be payable in respect of other injuries.
9 In Fellowes v Military Rehabilitation and Compensation Commission (2009) 240 CLR 28 ("Fellowes"), the majority judgment reinforced that approach. The majority judgment also drew attention to the need to assess compensation for each injury by reference to the effect of the injury on the functional capacities of a normal healthy person, rather than by reference to the effect on the pre-existing capacities of the claimant.
10 The majority judgment said at [23]-[28]:
23 The respondent submitted that there were two reasons to conclude that the Guide required determination of the degree of impairment resulting from an injury by reference to the pre-existing capacities of the particular applicant for compensation. First, the respondent pointed to the repeated references in the Guide to "percentage whole person impairment". Secondly, the respondent pointed to the statement made in the introductory section of the Guide which is set out earlier in these reasons, that "[w]here two or more injuries give rise to the same impairment a single rating only should be given".
24 The references in the Guide to "whole person impairment" identify the "methods by which the degree of permanent impairment [resulting from an injury is] expressed as a percentage" (s 28(1)(c)). The percentages stated in the Guide describe "the extent of each impairment as a percentage value of the functional capacity of a normal healthy person". The references to "whole person impairment" that are found in the Guide do not direct attention to the effect of an injury or disease on a particular individual. On the contrary, the effect to be assessed is by reference to the functional capacities of a normal healthy person.
25 The statement in the Guide, that "[w]here two or more injuries give rise to the same impairment a single rating only should be given", must be understood as directing attention to an impairment as that term is defined in the SRC Act. That is, the reference to the "same impairment" must be understood in terms of the particular identified effect on particular bodily parts, systems or functions. Contrary to the respondent's submission, this statement in the Guide is not to be understood as requiring a single rating to be given whenever each of two injuries is assessed as yielding the same degree of impairment of two separate parts of the body.
26 The text of the Guide is therefore to be construed as providing that the whole person impairment to which it directs attention requires comparison with the "functional [capacities] of a normal healthy person" rather than the capacities of the particular applicant as they existed immediately before the injury in question. The reference to two injuries causing the "same impairment" requires attention to the particular identified effect on bodily parts, systems or functions that is said to have resulted from the two injuries. It is, therefore, not necessary to consider, in this case, the application of the principle, stated in Canute, that if there were some conflict between what is required by the SRC Act and what is provided by the Guide, it is the Act that must be given priority.
27 It is, nonetheless, important to make the further point that, on its proper construction, s 24(5) of the SRC Act directs attention to the degree of impairment that results from the injury resulting in the impairment identified in s 24(1). The two sub-sections of s 24 are not to be read as requiring or permitting a different identification of "impairment" in their respective applications. In the application of both sub-sections the focus must fall upon "the loss, the loss of the use, or the damage or malfunction" (s 4(1), "impairment") of a part of the body or a bodily system or function or part of a bodily system or function. And in the present case there were separate losses of use of, or damage to, two parts of the body.
28 In this last connection, the respondent submitted that, despite there having been separate injuries to each knee, there was in fact only a single effect on (a loss of use of) a bodily function (the function of using the lower limbs). It may be doubted that the function of using the lower limbs is properly described as a bodily function. But even if the words could be understood as extending thus far, the respondent's argument, on examination, is no more than a restatement of the argument that the degree of impairment to be determined under s 24(5) is the degree of impairment as a whole person of the particular applicant for compensation. For the reasons already given, that construction should be rejected.
(citations omitted)
11 The question of law in the present case (which is set out later) raises the issue of whether the approach taken by the AAT to assessment of impairment resulting from the applicant's injuries gave proper effect to the directions of the High Court about the operation of the SRC Act and the need to make appropriately individual assessments of compensation for separate injuries.