Effects of Consecutive Rebound Jump Training Dependent on Muscles to which Electromyostimulation is applied

Abstract

Background Consecutive rebound jump (RJ) training performed while applying electromyostimulation (EMS) to the calf muscle increases muscle strength and Achilles tendon stiffness, and enhances jump performances. The present study investigated whether the effects on jumping performance of consecutive RJ training with EMS differed depending on lower limb muscles on which EMS was superimposed. Methods Forty-nine men who trained every other day for 4 weeks were divided into five groups: a non-EMS group and EMSCALF, EMSAF, EMSPF, and EMSTHIGH groups in which EMS was applied to the calf, anterior femoris, posterior femoris, and all thigh muscles, respectively. Participants were only instructed to perform RJs at the same spot but were not instructed on jumping action and its kinesthetic sensation. Results After training, the jump heights increased in all EMS-applied groups. Kinesthetic sensation and the joint angles in which maximum voluntary isometric contraction torque increased differed depending on the muscles on which EMS was superimposed during RJs. The EMSCALF group experienced a clear “bounce” sensation during jumping and increased ankle plantar flexion torque and Achilles tendon stiffness in the ankle dorsiflexion position. The body was moved backward in the EMSAF group during RJs but forward in the EMSPF group. The EMSTHIGH group felt the easiest to jump during jumping. Conclusions The application of EMS to lower limb muscles during RJs enhanced jumping performance, but its mechanism and effects depended on the muscles to which it was applied.