ECCENTRIC MUSCLE PERFORMANCE OF ELBOW AND KNEE MUSCLE GROUPS IN UNTRAINED MEN AND WOMEN

Maximal voluntary eccentric (ECC) and concentric (CON) capacity of knee and elbow muscle groups was investigated in healthy untrained men (N = 40) and women (N = 50), 21-67 yr of age. Purposes of the study were to describe torque-velocity and ECC-CON relationships. and to compare these relationships among muscle groups and between genders. Average torque was measured at angular velocities of 30-degrees and 120-degrees.s-1 from knee flexor (KF), knee extensor (KE), and elbow flexor (EF) muscle groups unilaterally, using an isokinetic protocol including gravity compensation. Data were analyzed using ANOVA procedures, and a significance level of 0.01 was used for all hypothesis testing. Torque-velocity relationships were similar for each muscle group and gender; i.e., ECC average torque did not change as a function of velocity and CONC torque decreased as angular velocity increased. Women generated greater ECC relative to CONC torque than men in upper and lower extremity muscle groups. Muscle groups differed in ECC relative to CONC capacity in both men and women, with ECC/CONC ratios being greater for KE and EF than KF. In all muscle groups, the magnitude of ECC-CONC differences increased as angular velocity increased. Genders differed in relative strength balance between muscle groups, with men exhibiting greater KF/KE and EF/KF torque ratios than women for both ECC and CONC actions. Results of this study contribute to the body of knowledge concerning ECC muscle performance in untrained adult men and women. Findings concerning gender and muscle group differences in muscle performance should provide useful information for interpreting results of isokinetic testing of untrained adults, as well as for guiding training and rehabilitation programs.