Effect of static stretching and jogging on knee extension isokinetic peak torque
The purpose of this study was to determine whether static stretching alone or combined with a warm-up affected isokinetic peak torque (IPT) of the quadriceps at both slow and fast velocities. Twenty physically active males (22.1 ± 2.4 years) performed maximal knee extensions under four conditions: no stretch control, stretch only, 5 min jog followed by stretches, and stretching followed by a 5 min jog. Total stretching volume was 360 s. A Biodex System 3 isokinetic dynamometer was used to measure IPT at 60 and 300°/s. A 2 × 4 repeated measures ANOVA revealed that IPT was significantly different among the four test conditions (F=3.09, p=0.03) and follow-up comparisons revealed that the mean IPT of the stretching trial was 9.9 N·m less than the control trial (Effect size =0.19–0.42). Neither of the warm-up conditions combined with stretching were significantly different from the control. It was concluded that stretching affects IPT to a similar extent at both velocities tested, and that jogging done either prior to or after stretching does not appreciably alter knee extension IPT. The lower IPT following static stretching precludes recommending this activity prior to a maximal effort.