Abstract
Horsepower of knee flexion and knee extension of seven sprint-trained runners and seven distance-trained runners was obtained at 60 and at 210 degrees per second by use of an isokinetic apparatus to test the hypothesis that no significant difference in horsepower would be manifest between the two rates of dynamic movement. The t-test for paired observations was used to test the hypothesis. The data established that a significant difference in horsepower existed between rates of displacement for the knee flexors of the sprint runners but not for other comparisons. Distance runners developed greater horsepower at slow tension while sprint runners generated greater horsepower at rapid tension. The groups did not maintain the same horsepower relationship between knee flexors and knee extensors as rate of movement increased. Generation of knee extension horsepower by distance runners was more dependent on muscle strength than on speed of movement while generation of knee extension horsepower by sprint runners was more dependent on speed of movement than muscle strength. Sprint runners used a greater percentage of knee flexion strength for the generation of horsepower than did distance runners.