RELATIONSHIP BETWEEN ISOKINETIC CONCENTRIC AND ECCENTRIC CONTRACTION MODES IN THE KNEE FLEXOR AND EXTENSOR MUSCLE GROUPS

We investigated whether in normal subjects isokinetic concentric and e ccentric strength variables were related in order to have a better pic ture in relation to rehabilitation and possible injury prevention. We studied the relationship between isokinetic concentric and eccentric p eak torque, total work, and average power oi knee extension and knee f lexion at 60 degrees/sec and 120 degrees/sec in 42 young Chinese adult s (22 males, age = 27 +/- 6.9 years; 20 females, age = 24.9 +/- 5.05 y ears) using the Cybex 6000 isokinetic dynamometer. Repeated analysis o f covariance was used to compare the means between concentric and ecce ntric variables adjusted by limb dominance, speed of testing, and the muscle groups tested. A highly significant correlation was found betwe en all concentric and eccentric variables, with correlation coefficien ts (r) ranging from 0.67 to 0.93. All but two of the eccentric variabl es were significantly greater than the concentric variables. Concentri c and eccentric knee flexion to knee extension (H:Q) ratios were poorl y correlated, with r ranging from 0.359 to 0.645. Although there is an acceptably high correlation between isokinetic concentric and eccentr ic strength variables oi knee flexion and extension in young healthy i ndividuals, we recommend measuring concentric and eccentric strength t o plan a proper rehabilitation program and to assess muscle groups in a given contraction mode.