Sports Injury

Physio-acoustic therapy and placebo effect in muscle recovery

By Dr. Peter M. Tiidus, Roula Markoulakis, Drew Murray, Marco Karkkainen and Dr. Heidi Ahonen-Eerikainen.

Departments of Kinesiology & PE and Music Therapy, Wilfrid Laurier University

Physioacoustic therapy has been advocated as an effective means of enhancing muscle recovery following intense physical activity. When muscles are overused or exposed to unaccustomed activities or very intense exercise or sport, small micro-trauma can occur to muscle micro-structures. This will result in a sustained period of diminished ability to produce maximum force and may also result in feelings of muscle soreness and stiffness due primarily to repair related muscle inflammation. The use of physioacoustic therapy has been advocated for athletes seeking to enhance performance recovery between competitions and for other active individuals who may experience muscle soreness following heavy physical work or activity. This initial study sought to assess the effectiveness (or lack there of) of physioacoustic therapy in enhancing recovery of indices of muscle damage following a standard bout of unaccustomed muscular activity.

Young, healthy male and female adults were randomly assigned to one of three groups: control, placebo, or treatment. All groups were asked to perform a series of maximum effort eccentric (lengthening) triceps muscle contractions using an isokinetic CYBEX NORM apparatus. This exercise was followed by either no treatment (control), sham physioacoustic treatment (placebo) (with the chairs turned off and the subjects lead to believe that treatment was occurring), or actual physioacoustic treatment (treatment), using a progressive physioacoustic treatment regimen lasting 30 minutes. Both placebo and treatment groups were exposed to the physioacoustic chairs (with chairs either turned off or functioning) on days 1, 2, 3 & 4 post-exercise. Measures of triceps muscle soreness and rates of strength loss (as isometric and concentric isokinetic forces) and regain (as indices of muscle damage and recovery) were made prior to the eccentric exercise (to establish baseline) and then on days 1, 2, 3, 4 & 7 following exercise (recovery).

Ability to generate muscle force was depressed in all groups on days 1-3 and had returned to pre-exercise values by days 4-7 in both the placebo and treatment groups. The ability to generate muscle force in the control group was slower to recovery and had not yet returned to baseline by 7 days post-exercise. Muscle soreness was also elevated in all groups on days 1-2 post-exercise. Placebo and treatment groups both reported no more muscle soreness by day 3 post-exercise while the control group continued to report muscle soreness though days 3-4 post-exercise.

It was concluded that while the physioacoustic treatment appeared to enhance the recovery of indices of muscle damage faster than what occurred with non-treated control subjects, the rate of recovery induced by physioacoustic treatment was no different from the enhanced recovery rate seen in the placebo treatment group. Hence the success of physioacoustic therapy in improving the rate of post-exercise muscle recovery can in this instance be attributed primarily to a placebo effect.

2007 Tiidus, P., Markoulakis, R., Murray, D., Karkainen, M. & Ahonen-Eerikainen, H.: Physio-Acoustic Therapy and Placebo Effect in Muscle Recovery. Applied Physiology Nutriton & Metabolism. Journal of the Canadian Society for Exercise Physiology, Vol. 33 (supplement), Nov. 2007.