The influence of hip position on quadriceps and hamstring peak torque and reciprocal muscle group ratio values.

The purpose of this investigation was to determine the effect of hip position and test velocity on the quadriceps and hamstring reciprocal muscle group ratio. Twelve subjects (7 male, 5 female) were tested for isokinetic peak torque at 60, 180, and 240 degrees /sec from the seated and supine positions. Gravity correction was obtained to determine quadriceps and hamstring peak torque, and to determine the reciprocal muscle group ratios. Results indicated there was a decrease in production of peak torque with an increase in test velocity for both muscle groups. Also, peak torque values were greater in the seated than supine position for both muscle groups. The influence of test velocity on the quadriceps and hamstring reciprocal muscle group ratio was to increase the ratio with increasing test velocity. Also, the reciprocal muscle group ratio increased from the supine to the seated position at all test velocities. These findings suggest that determination of the quadriceps and hamstring reciprocal muscle group ratio is influenced by both hip position and test velocity. Because many athletic activities involving running and sprinting occur from a hip position closer to the supine test position, evaluation of peak torque and determination of the reciprocal muscle group ratio may be more appropriate from the supine position. Also, normative data establishing target ratios should be determined from several test velocities. J Orthop Sports Phys Ther 1989;11(3):104-107.