title: Therapeutic effect of high speed voluntary muscle contractions on muscle soreness and muscle performance.
abstract: The purpose of this study was to examine the effects of a high velocity therapeutic exercise regimen (20 voluntary maximum knee extension/flexion contractions at approximately 300 degrees /sec, 3-min recovery repeated for 6-sets), on muscle soreness and muscular performance. Data was collected immediately prior to inducing muscle soreness with an eccentric stepping exercise (baseline), immediately after the muscle soreness exercise bout, at 24 hours (when intervention was initiated to the experimental group), and at 48 hours after the muscle soreness bout. Dependent variables measured for the ten subjects were: 1) Maximum voluntary contraction (MVC) by the quadriceps;2) Peak torque (PT) by the quadriceps at high resistance;3) Total work (TW) by the quadriceps at low resistance;4) Intensity (I) of muscle soreness of the quadriceps;5) Amount of quadriceps [Area-(A)] affected by muscle soreness;6) Soreness perception index (SPI) of quadriceps (IXA).MVC, PT, and TW percent decrease from baseline were significantly less (p < 0.05) for the experimental group than the control group at 48 hours postmuscle soreness bout (MVC: 8.3 versus 33.4%; PT: 3.8 versus 12.1%; TW: 2.3 versus 13.8%, respectively). SPI was also significantly less (p < 0.05) at 48 hours postmuscle soreness bout for the experimental versus control [0.8 (I = 0.027 x A = 29.3) versus 1.4 (I = 0.029 x A = 46.1)]. The data from this study indicates that a therapeutic regimen of high speed voluntary muscle contractions is effective in decreasing muscle soreness and facilitating return of normal muscular performance. J Orthop Sports Phys Ther 10(12):499-507.