The effect of stretching on muscle responses and postural sway responses during computerized dynamic posturography in women and men.

Objective: To evaluate the effect of stretching on the parameters of postural sway and on the kinematic variables associated with balance control in women and men.

Design: Mixed repeated measures design with 2 levels.

Setting: Research laboratory.

Participants: Fifteen women and fifteen men (mean age 23.4+/-2.2).

Intervention: Two separate sessions of (1) lower extremity stretching and (2) no-stretching, immediately prior to balance testing with simultaneous surface electromyographic (EMG) recordings of muscle responses.

Main Outcome Measures: EMG latencies and average amplitudes for 4 lower extremity muscles for the preferred stance limb during computerized dynamic posturography (CDP) tests, specifically the Postural Evoked Response Test, Adaptation Test, Motor Control Test, Sensory Organization Test, and Unilateral Stance Test.

Results: Analyses of variance indicated no significant main effect for stretching and 2 significant main effects for gender for the Motor Control Test (P=.021) and latency of tibialis anterior (P=.009). Analyses of covariance with covariants of height and active knee extension revealed no significant main effect of stretching or of gender on muscles responses or CDP performance.

Conclusions: In both women and men, lower extremity stretching did not significantly affect muscle responses or performance during CDP.