Acute Effects of Whole Body Vibration on Shoulder Muscular Strength and Joint Position Sense

Functional changes following whole body vibration (WBV) training have been attributed to adaptations in the neuromuscular system. However, these changes have mainly been observed in the lower extremity with minimal change to the upper extremity. The purpose of the study is to examine the acute effect of shoulder vibration on joint position sense and selected muscle performance characteristics (peak torque, time to peak torque, and power). Forty young individuals (19.84 ± 1.73 yrs, 171.41 ± 7.73 cm, 70.07 ± 9.32 kg) with no history of upper body injuries were randomly assigned to an experimental (Vibration) or control (No-Vibration) group. To assess shoulder propriocep-tion, active and passive joint position senses were measured on both internal and external rotation of the shoulder. The muscle performance variables (peak torque and time to peak torque) were measured using isokinetic dynamome-ter with the velocity of 60°/sec. After three bouts of 1 minute vibration training, the experimental group demon-strated a significant improvement in the internal rotation peak torque, time to peak torque and external rotation time to peak torque (p<0.05). However, no-significant differences were revealed for joint position sense, external ro-tation peak torque, and time to peak torque between the groups. Our findings suggest that short bouts of vibration treatment have a significant effect on shoulder muscle characteristics.