EMG Analysis of Muscles Activity in Handgrip Movement During Overhead Throw in Softball
Most of our daily activity required gripping movement especially in sports which involve inflexor musculature contraction of the forearm and hand. Sports such as softball need a greater handgrip motion and strength to perform the skill especially in overhead throw skill. Gripping action has not been given emphasized in sport sciences because the motion only involved small muscles. However, the contribution from these small muscles group plays significant role in the execution of overhead throw skill. Therefore the purpose of this study is to determine the muscles activity in handgrip motion during overhead throw. Five healthy female softball players performed overhead throw with surface EMG recorded on extensor digitorum, flexor digitorum, abductor pollicis longus, flexor pollicis brevis, abductor pollicis brevis and flexor pollicis brevis on their dominant hand. Result showed that flexor policies brevis have a greatest contraction in overhead throw with the peak percentage of 95% and 28% in average percentage of active muscles. Flexor pollicis brevis is important in cocking and acceleration phase as reflected by thehigh amplitude in the electromyography. Flexor pollicis brevis contraction cause the thumb flexion and opposition that are essential in gripping movement. Both of these phases need the thumb flexion to forward the ball towards the target. The findings of this study suggest that muscles in handgrip motion also play important roles in the execution of a complete overhead throw skill.
Keywordsó Electromyography, Handgrip, Overhead Throw, Softball.