Will the Slendertone products increase muscle strength in healthy muscle in an ordinary consumer?
92 Dr Bakker's evidence for the applicant was that the fact of a muscle contraction does not mean that it is strengthening in the absence of any resistance. He testified that the consensus in the scientific articles and literature is that there is some effect from the use of EMS on healthy muscles under certain specific conditions. Those conditions are that the limb to which EMS is applied is immobilised or attached to some form of weight system so that the muscle is working against resistance or under isometric conditions. The studies had all been done on the quadriceps at the top of the upper leg. EMS was found to have a minimising effect in cases of muscular atrophy where the persons concerned were unable to exercise. He said that in the case of a healthy person EMS did not really bring any benefit better than those obtainable by voluntary exercise.
93 His report says that in order to tone and firm particular parts of the body it was necessary to reduce subcutaneous body fat and increase the size of the muscles in the particular area and it was highly unlikely that the Gym Body 8 and Top Tone 12 would achieve those aims in the absence of any resistance, the absence of any elevation in heart rate and with decreased effectiveness of the units in regions of higher subcutaneous body fat.
94 Dr Coombes' evidence, as previously stated, is that to increase muscle size it is necessary to continually stress the muscle by overload through resistance. He said there was minimal evidence in a couple of studies published in lower level journals that slight increases in muscle size result from EMS. However, it was necessary to understand these firstly in the context of stimulation parameters and electrode size. Also, in most of those studies the muscle is being contracted against an isometric device so that it is working against a resistance.
95 Therefore both Dr Bakker and Dr Coombes were of the opinion that the Slendertone products could not cause any change to muscle size or strength because they did not cause muscles to contract isometrically or against any resistance.
96 Both Dr Bakker and Dr Coombes were challenged in cross-examination on the basis of general articles and studies, which supported the assertion that the use of EMS alone can strengthen muscle. A number of these sources also arose in the evidence of Dr Crowe. These included a study by Currier and Mann as well as a text by Wilmore and Costill. Dr Bakker stated that the authors of the text were referring to EMS under conditions where there are high levels of stimulation under conditions of resistance (e.g. leg or hip strapped at a certain joint articulation). He regarded this as supported by the description of the chapter in which the passage relied upon appears as dealing with 'Neuromuscular Adaptations to Resistance Training'.
97 Dr Crowe' s evidence for BMR was that authors of books on EMS and exercise physiology as well as the writers of review articles in respected journals and regulatory bodies are in consensus that there are strengthening and physiological effects of EMS and that these are comparable to voluntary exercise. He cited an article by Lake titled 'Neuromuscular Extra Stimulation and Voluntary Exercise' (1992) 13(5) Sports Medicine Journal 320 based on examination of 142 pieces of research. This article considers investigations which have looked at EMS 'under isometric conditions' compared to voluntary isometric exercise and non-exercise groups. It states 'there is a consensus that the force increases induced by [EMS] are similar to, but not greater than those induced by voluntary training'. It stated that 'it appears that when [EMS] and voluntary exercise are combined there is no significant difference in muscle strength after training when compared to either [EMS] or voluntary exercise alone' (at 320).
98 Dr Crowe also cited AL Baker, Neuromuscular Electrical Stimulation: A Practical Guide (4th ed) at 48 where it is stated:
'It can now be said unequivocally that [EMS] can, by itself, strengthen normal healthy muscle, and can even enhance the force generating capability of the athlete exhibiting some degree of hypertrophy.' (emphasis added)
He relied on this to support the view that EMS can by itself strengthen normal healthy muscle. Against this the applicant points to the statement in the same text at 49 that 'the significance of [EMS] programs for the healthy individual who has not sustained injury needs to be carefully evaluated', asking whether it adds anything not attainable by other means. Further at 49-50 the same article states that:
'Addition of a stimulation program does not appear to alter the strengthening profile quantitatively beyond that which can be achieved through standard voluntary exercise in a well defined pattern in healthy individuals. If an individual can exercise, there is only a hint of evidence that the addition of [EMS] to a voluntary exercise program will provide an altered outcome.' (emphasis in original)
99 Reference was made by Dr Crowe to the graph in the Baker text at 50 referring to the effects of EMS compared to voluntary muscle strengthening. The graph is based on data compiled from four studies of normal individuals subject to strength training programs of voluntary or EMS induced exercise. The applicant contends that examination of the studies clearly shows that EMS was applied under isometric conditions involving strapping or restraint of limbs. The studies were those by Currier and Mann; Lai, De Domenico and Strauss; Selkowitz; and Szeto, Strauss and De Domenico (cited at footnotes 50, 115, 189 and 205 of the Baker text). Examination of these supports the applicant's contention.
100 In his evidence Dr Crowe expressed the opinion that the Slendertone products were in fact used isometrically. He testified that contracting the muscle using the body's own force is an isometric exercise so that EMS is a form of isometric exercise.
101 In cross-examination a definition of 'isometric' was put to Dr Crowe from The Australian Concise Oxford Dictionary, (2nd ed, Oxford University Press, Melbourne, 1992) at 599 where the word is relevantly defined to mean 'developing tension while the muscle is prevented from contracting'. He disagreed with this definition on the basis that he considered it envisages gross joint movement and this was not a necessary part. He preferred the definition of 'isometrics' at the same page (similar to that in The New Shorter Oxford English Dictionary at 1425) defining isometrics as 'a system of physical exercises in which muscles are caused to act against each other or against a fixed object'. He considered that the use of the body's co-contraction supplied the counteracting force so that the contraction of the muscle by EMS was a form of isometric exercise.
102 The applicant submits this is clearly inconsistent with other evidence of Dr Crowe. Elsewhere Dr Crowe had agreed that Slendertone products do not use strapping or restraints. . Additionally the applicant submits that the view is inconsistent with the studies of EMS which describe the use of EMS as a distinct form of exercise. Further, the applicant submits that it is contrary to the evidence of Dr Bakker, which should be preferred. In my view, the weight of evidence is that use of EMS is not considered to be an isometric exercise and I accept that evidence in preference to that of Dr Crowe on this issue.
103 A further issue which arose in the evidence of Dr Crowe is whether the Slendertone products were to be regarded as superior to machines which had been the subject of some of the studies of EMS. Dr Crowe was referred to a study by Porcari and others ('Effects of Electrical Muscle Stimulation on Body Composition, Muscle Strength, and Physical Appearance' (2002) 16(2) Journal of Strength and Conditioning Research 165-172). The authors there found no statistical difference in body composition, waist girth, muscle strength and physical appearance of subjects after the use of a consumer EMS product 3 times a week for 8 weeks. He was also referred to the passage from Lake, 'Neuromuscular Electrical Stimulation' (1992) 13(5) Sports Medicine 320-327 that 'multiple muscle group [EMS] as used in muscle toning clinics has proven totally ineffective in muscle strengthening' citing (Lake 1988, Lake and Gillespie 1988). He dismissed this evidence on the basis that the products there being tested were not products regulated like Slendertone products. He testified that it could be argued that Slendertone products were not consumer products but rather medical products because there are produced in a medically accredited factory audited by the US Food and Drug Administration and controlled by the Medical Device directive.
104 In forming his view of the Slendertone products Dr Crowe relied heavily on trials which BMR had conducted on its products in 1999, 2000, 2001 and 2002. The 1999 study tested the Slendertone Gymbody 8. It claimed the product improved body image, perceived flatness, firmness and strength with reduction in abdominal girth, strength maintenance and improvements in posture. The 2000 study, undertaken by application of Slendertone Flex, resulted in a report similar to the 1999 study but noted that improvements were greater than those previously observed. The 2001 study (applying the Slendertone Bottom and Thigh Toning System) sought to measure the effect of EMS on the muscles of the bottom and thighs over an 8 week period. It reported perceived improvements in firmness, tone and shape as well as improvements in body satisfaction and general well-being. The 2002 study (which applied a similar system to 2001) reported statistically significant improvements in strength of the quadriceps and hamstring muscles and significant improvements in perceived firmness and shape of the bottom and thigh area. It is to be noted that the reports, apart from the first, do not identify as being used in the tests any of the Slendertone products relevant in this proceeding as the source of the EMS.
105 The applicant submits that these 4 studies suffered from defects in research methodology and design so that little weight should be given to them. Issues thus raised are that the trials were done for BMR and that Dr Crowe, one of the persons responsible, was paid by it; they had not been peer reviewed; and the absence of such review was not adequately explained by avoidance of exposure to competition. Additionally, few overweight subjects were included; recruitment by newspaper advertisement had not been random; and other inappropriate qualifications excluded persons with certain characteristics. There was also a reward for participants, who knew whether or not they were in the treatment group and saw a video on treatment prior to separation into treatment and control groups. Also, there was a large variance in skin fold data due to a defective measuring device; the changes in dynamometer strength testing results of the treatment group were statistically and practically insignificant; data were missing; and the use of girth as a measurement of muscle size was extremely problematic. Likewise it is said that little weight should be given to the submission of one of the studies to the US Food and Drug Administration because it dealt with a different machine to the ones at issue in this action and the approval of the Food and Drug Administration had been granted after the publications the subject of these proceedings.
106 When Dr Crowe stated in his report that 'many studies have shown that EMS improves strength', he relied upon the following studies. The first group were the BMR studies considered immediately above. The second was a Trinity College Dublin study in abstract form only. It examined the '[e]ffects of neuromuscular stimulation and 'Ab worker' and supervised exercise on static, strength and dynamic endurance of the abdominal musculature'. It concluded that neuromuscular stimulation and supervised training were of equal benefit in terms of static isometric strength and dynamic endurance. The third group was the Baker text and the Lake article and other similar articles. As has been seen, the applicant submits this latter group has been shown to have involved examination of EMS applied under resistance or isometric conditions.
107 Dr Crowe also referred in his report to studies where EMS is not applied under resistance or isometric conditions. However, some of these were not available in the public domain and had not been peer reviewed. In the case of the Becker study (cited at footnote 4 of Dr Crowe's report) and the Le Faou and Pennamen report, weight loss had been experienced by participants. In the case of the former there had not been any control group.
108 The applicant submits that, based on the above evidence, the Court should not accept any argument from either the respondents or BMR that it has been shown that the Slendertone products as used by the consumer are in fact capable of strengthening muscles.
109 The evidence supports the view that the Slendertone products may increase muscle strength in cases of muscular atrophy. The effect of EMS on muscular strength generally is more difficult to decide on the evidence. The difficulty comes partly from the inability to assess the relative credibility of the evidence of Drs Bakker and Coombes, based on studies of a limited nature as earlier explained, against the studies referred to and relied upon by Dr Crowe when the authors of those studies are not themselves called. The respondents seek to have the Court find that Drs Bakker and Coombes did not conduct tests using scientific methods and approached their tests with pre-conceived views; that Mr Wright did not conduct tests at all; and that Dr Crowe was the only expert to exhibit a proper scientific approach.
110 In these circumstances I find myself in the same position as Dowsett J in Danoz at [74]-[77]. I do not believe that this conflict of opinion concerning EMS can be resolved by my preferring one view to another when I am not persuaded by the evidence that one is clearly correct. Reference also to the BMR information considered below makes apparent the serious division in expert opinion on the issue here under consideration. It can only be resolved by extensive research and experience over time. While an enormous amount of time in this proceeding was spent in hearing evidence, it could also only be resolved by considerably more evidence and experimentation under conditions satisfying all requirements of scientific method. I therefore reach the position where I do not consider the evidence establishes conclusively whether or not EMS as delivered by Slendertone or otherwise increases and strengthens healthy muscle. At least on one view, it is possible to strengthen healthy muscles by the use of EMS.