Muscular Imbalances
Bilateral and anterior-posterior muscular imbalances in swimmers
Ted Becker, Ph.D. and Rod Havriluk, Ph.D.
In J. P. Vilas-Boas, F. Alves, A. Marques (Eds.), Biomechanics and Medicine in Swimming X. Portuguese Journal of Sport Sciences, 6(Suppl. 2), 327-328.
The purpose of this study was to determine the relative magnitude of bilateral (left/right) and anterior-posterior (front/back) differences in swimmers. Peak hand force was measured with Aquanex during aquatic exercise (horizontal arm abduction and adduction in a standing position) and swimming (freestyle and backstroke).
The peak force values were significantly higher (p<.01) for exercise adduction than abduction and for the swim stroke with the arm in the adducted position (freestyle) rather than the abducted position (backstroke). The magnitude of the anterior-posterior difference was large for both exercise (1.5σ) and swimming (.8σ). Bilateral differences were trivial (.1σ, ns) in comparison. A training regimen that strengthens the arm abductors may not only decrease the incidence of injuries in all four strokes, but also increase hand force and, therefore, improve performance in backstroke.