EMG characteristics of forearm flexor muscles during static explosive grip exertion

Abstract

　The purposes of this study are to examine the contribution of each flexor muscle to explosive strength by measuring EMG of forearm flexor muscles during static explosive grip (SEG) exertion using surface electromyography, and to find the relationships between force-exertion parameters and EMG parameters. Subjects are 10 healthy young male volunteers (age: 23.6 ± 4.1yr) with no upper-limb injuries.

　The reproducibility (ICC = 0.635-0.971) of EMG parameters (peak frequency, integrated EMG (IEMG), maximal amplitude time) was higher in the flexor digitorum superficialis and flexor pollicis brevis muscles than in the flexor digiti minimi brevis muscle. High relationships between force-exertion parameters and EMG parameters were not observed in any flexor muscle. The maximal amplitude time in SEG exertion was longer in the flexor digitorum superficialis muscle than the flexor pollicis brevis and flexor digiti minimi brevis muscles. During the force development phase of the force-time curve in SEG exertion, it is possible that the hand flexor muscle fibers (flexor pollicis brevis and flexor digiti minimi brevis) are mobilized quickly, then the forearm flexor muscle fibers (flexor digitorum superficialis).