The effect of velocity on load range during isokinetic hip abduction and adduction exercise

The purpose of this study was to quantify the components of acceleration, load range and deceleration through a velocity spectrum during concentric hip abduction and adduction isokinetic exercise, and to investigate the effect of load range on peak torque and work done. 16 male healthy subjects performed 3 maximal concentric reciprocal hip abduction and adduction gravity corrected repetitions in a fixed order at 60, 120, 180, 240, 300, 360 and 420° · s-1, with a 30 s rest between velocities. Hip abduction and adduction results revealed that load range significantly decreased while acceleration and deceleration ROM significantly increased (p<0.05) with each increase in velocity. When the total peak torque data was corrected for load range there was a significant decrease (p<0.05) in peak torque at velocities of 300° · s-1 and above, for both hip abduction and adduction. Load range correction also resulted in a significant decrease (p<0.05) in work done at velocities of 120° · s-1 and above, for both hip abduction and adduction. The results demonstrate an inverse relationship between isokinetic velocity and load range during concentric hip abduction and adduction, and suggest a need for the clinician to carefully consider velocity selection when performing exercise on an isokinetic device.