The effect of eccentric strength training at various speeds on concentric strength of the quadriceps and hamstring muscles.

This study investigated the effect of eccentric training on concentric strength of the quadriceps and hamstring muscles. The dominant legs of 43 college-age males were pretested concentrically using the KIN-COM(R) at speeds of 60 and 180 degrees /sec. Twenty-eight treatment subjects trained eccentrically at one of the testing speeds for a period of eight weeks; the remainder served as the control group. Prior to each training session, the subjects gave a subjective evaluation of muscle soreness. Delayed muscle soreness did not affect the subjects' ability to train eccentrically. A concentric posttest was taken to determine any treatment effects. The quadriceps muscle did not show any significant change after eccentric training. Eccentric training at 60 and 180 degrees /sec significantly increased the concentric strength of the hamstrings. Eccentric training does appear to be effective in developing concentric strength in the hamstrings. The speed of eccentric training was not a factor in concentric conditioning. J Orthop Sports Phys Ther 1991;13(5):226-230.