The Effects of Static Versus Dynamic Stretching on Average Power in the Young-Adult Athletic Population

Abstract

Study design: Single-blind randomized study Objectives: The purpose of the current study was to compare the effects of static and dynamic stretching in the young-adult athletic population in terms of average knee extensor and flexor muscle power. Background: Stretching prior to exercise is a common practice for many athletic persons, in which varying protocols frequently including static or dynamic stretches. Literature has shown deficits in muscle performance lasting up to one hour as a result of performing static stretching directly prior to activity; alternatively, dynamic stretching has been found to induce positive effects. Method: Forty young-adult athletes were systematically assigned to static or dynamic stretching groups and performed their respective quadriceps and hamstrings stretches according to their group assignment protocols. Pre-test and post-test measurements of hamstrings and quadriceps average power (Watts) at 60 ̊/sec and 180 ̊/sec were obtained using a Biodex Isokinetic Dynamometer. Results: A mixed design ANOVA showed that there was a significant main effect for stretching type and time (pre-stretch, post-stretch) for dynamic stretching in knee flexor and extensor average power at 60 ̊/sec (p<0.05), which demonstrates an improvement in quadriceps and hamstrings muscle strength. No significant main effect for stretching type and time was found in knee flexor and extensor average power at 180 ̊/sec (p>0.05). Conclusion: Dynamic stretching exercises in the form of straight leg kicks and butt kicks may increase quadriceps and hamstring muscle performance at “strength speed” in terms of average power and may be beneficial to young-adult athletes when performed prior to activity. Contribution of paper a. Stretching is an important component of warm-up routines for young-adult athletic subjects. b. Dynamic stretching increases knee extensor and flexor muscle powers at “strength speeds.” c. Static stretching does not affect knee extensor and flexor muscle power.