Unilateral plantar flexors static-stretching effects on ipsilateral and contralateral jump measures

The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (ss) on the passive range of movement (rom) of the stretched limb,surface electromyography (semg) and single-leg bounce drop jump (sbdj) performance measures of the ipsilateral stretched and contralateral non-stretched lower limbs. seventeen young men (24 ± 5 years) performed sbdj before and after (stretched limb: immediately post-stretch,10 and 20 minutes and non-stretched limb: immediately post-stretch) unilateral ankle plantar flexor ss (6 sets of 45s/15s,70-90% point of discomfort). sbdj performance measures included jump height,impulse,time to reach peak force,contact time as well as the semg integral (iemg) and pre-activation (iemgpre-activation) of the gastrocnemius lateralis. ankle dorsiflexion passive rom increased in the stretched limb after the ss (pre-test: 21 ± 4° and post-test: 26.5 ± 5°,p < 0.001). post-stretching decreases were observed with peak force (p = 0.029),iemg (p<0.001),and iemgpre-activation (p = 0.015) in the stretched limb; as well as impulse (p = 0.03),and jump height (p = 0.032) in the non-stretched limb. in conclusion,ss effectively increased passive ankle rom of the stretched limb,and transiently (less than 10 minutes) decreased muscle peak force and pre-activation. the decrease of jump height and impulse for the non-stretched limb suggests a ss-induced central nervous system inhibitory effect. © 2015,journal of sports science and medicine. all rights reserved.