Abstract
The purpose of this investigation was to use magnetic resonance imaging (MRI) to examine the relationships between the cross-sectional area (CSA) of the flexors and extensors of the forearm and isokinetic peak torque at speeds of contraction from zero to 300 deg/sec. Ten men (mean ± SO = 23.9 ± 4.5 years) volunteered as subjects for this study. Peak torque values for flexion and extension of the forearm were determined at 0, 60, 120, 180, 240, and 300 deg/sec using a Cybex II isokinetic dynamometer. For the forearm flexors, the only significant (p < 0.05) correlations between muscle CSA and peak torque were at zero (r = 0.73), 60 (r = 0.85), and 120 deg/sec (r = 0.76). There were no significant (p > 0.05) correlations for the forearm extensors. It is likely that these findings were most influenced by the contribution of primarily fast-twitch fibers to peak torque at fast speeds of contraction and the differences in architecture (parallel versus pennate fiber orientation) of the forearm flexors versus extensor muscles.