FOREARM EXTENSOR AND FLEXOR MUSCLE EXERTION DURING SIMULATED GRIPPINGWORK - AN ELECTROMYOGRAPHIC STUDY

Objective. To study forearm muscular exertion during intermittent grip ping work at three different regimes resembling vocational work. Desig n. An electromyographic laboratory study of forearm fatigue during int ermittent gripping work at 25% MVC with 10/10, 20/10 and 30/10 s of wo rk/rest was performed. Background. Data from the literature indicate t hat forearm flexors as well as extensors are activated during gripping . However, no systematic quantitative assessment of the muscular exert ion has been made hitherto. Methods. Nine female subjects participated . EMG was detected from five forearm muscles, three extensors and two flexors. Zero crossing rate alterations were used as an index of fatig ue. Results. The results show significant (P<0.05) fatigue signs in at least two of the extensor muscles at all regimes while significant si gns of fatigue was seen only at the 30/10 regime for the flexor muscle s. Conclusions. Fatigue effects are generally larger on the extensor s ide. None of the studied regimes is acceptable from EMG fatigue point of view.