Isometric torque of the quadriceps femoris after concentric, eccentric and isometric training.

Twenty-seven normal, healthy women participated in this study, which investigated three methods of increasing the isometric strength of the quadriceps femoris through a six-week training program. Three experimental exercise groups were formed: A, eccentric, B, concentric, and C, isometric. The peak isometric torque of the quadriceps femoris was determined on the Cybex II Isokinetic Dynamometer before and after training. A total of 18 exercise sessions per subject were held. A two-way ANOVA with repeated measures revealed that while all three experimental groups significantly increased in isometric strength, no one method of training was superior. No interaction occurred in the population between the effects of pre- and posttraining scores and the type of training. The relationship between the experimental design and knee joint biomechanics may have precluded significant differences in strength gain among the experimental groups.