Acute changes in neuromuscular activity in vertical jump and flexibility after exposure to whole body vibration

Abstract

This study was aimed to investigate the neuromuscular activity after 10 minutes of exposure to a whole body vibration (WBV) session.Twenty male young adults (24.8 ± 2.5 year olds) were randomized and divided into 2 groups: the vibration group (VG) was exposed to 10 minutes of WBV at 35 Hz; performed 10 minutes of WBV at 35 Hz (displacement = 5 mm; magnitude = 5 g); the nonvibrated group (NVG) was the placebo group that maintained the same position on the plate but without exposure to any type of vibration. Subjects were evaluated with counter movement jump (CMJ) and muscular flexibility by means of electromyographic (EMG) analysis recorded on the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and gastrocnemius lateralis (LG).The 10 minutes of WBV showed an increase in muscular flexibility, associated with a decrease of EMG activity in BF (P < .01) and jump height. The latter was associated with a reduction of EMGs activity in BF (P < .01). The control group did not show any significant difference in all considered parameters.These results support the hypothesis that 10 minutes of WBV had effects on flexibility and explosive strength performance influencing neuromuscular behavior through inhibitor effects on antagonist muscles more than the stretch reflex activity on agonist muscles.

Figure 1

Changes in surface electromyography (sEMG) measurements of AG (Agonist) muscles (averaged vastus medialis and lateralis), BF (biceps femoris, antagonist muscle), Ant/Ag (antagonist/agonist) ratio, LG (lateral gastrocnemius) in concentric phase before and after 10 minutes of WBV (10’WBV) in the VG. Data are presented as mean ± SD. Significant difference within group ^∗P < .05; ^†P < .01.