The Effects of Static Stretching Versus Dynamic Stretching on Lower Extremity Joint Range of Motion, Static Balance, and Dynamic Balance

Abstract

The purpose of this study was to examine the effects of static stretching (SS) versus dynamic stretching (SS) on lower extremity joint range of motion (ROM), static balance, and dynamic balance. Fifteen active subjects with tight hamstring and calf muscles participated. Hip flexion and knee extension ROM angle was measured using a fluid inclinometer. A closed-chain method of measuring ankle dorsiflexion ROM was used. Static balance was assessed in single-leg stance on a force plate using the time-to-boundary (TTB) measurement. The Star Excursion Balance Test (SEBT) was used to assess dynamic balance in three directions. These measurements were assessed before and after each of three interventions: DS, SS or warm-up alone (CN). The dependent variables included ROM measures (hip flexion, knee extension, and ankle dorsiflexion), SEBT measures (anterior (ANT), posterior-medial (PM), posterior-lateral (PL)), and TTB mean in anterior-posterior (AP) and medial-lateral (ML). Repeated measures ANOVA were used to analyze the data. There was a significant main effect (p 0.05) for the TTB (ML, AP) and there were also no significant interaction (p>0.05) between interventions (SS, DS, CN) and time. The less stiff muscles and more slack connective tissue around the joints following stretching might attribute to the increased joint ROM. The enhanced ability to maintain dynamic balance after an increased flexibility might be due to a desensitized stretch reflex. A less responsive stretch reflex could suppress the postural deviations, enhance the proprioceptive input, and thus make it easier to establish equilibrium. Another contributor might be elevated muscle and body temperature, which enhance nerve conduction velocity. The sensory systems might play a dominant role in regulating the static postural control. Additional research is needed to more clearly understand the relationship between altered ROM, balance and stretching.