Abstract
This study investigated intratester, intertester, and intrasubject reliability, within and between two test sessions, of reciprocal contractions of the quadriceps and hamstrings at 90°/sec and 200°/sec in healthy individuals. The MERAC (Muscular Evaluation Rehabilitation and Conditioning, Universal Corporation, Cedar Rapids, IA) was used to test the dominant lower extremity of 33 healthy subjects who attended two test sessions scheduled two weeks apart. For each observation, the subject performed four submaximal and three maximal warm-up reciprocal contractions prior to three maximal test contractions of reciprocal, knee flexion, and extension at each speed. Three observations occurred per test session, one by one examiner and two by a second examiner. The order of examiners and speeds was random. The variables of peak torque, average work, and average power were measured. All correlation coefficients for intratester and intertester reliability were statistically significant (p < 0.05). Further research is indicated to determine isokinetic testing protocols that optimize stability of performance.