Relationships between peak torque, peak angular impulse, and average power in the thigh muscles of subjects with knee damage.

The purpose of this study was to determine the relationship between the isometric and isokinetic peak torque (PT) (speed of movement 0, 60, and 180 deg/s) and the peak angular impulse (PAI) and average power (AP) of multiple contractions (180 deg/s) of the quadriceps and hamstrings in 29 patients with a chronic, complete deficiency of the medial collateral ligament (MCL) of the knee. At every test speed the Pearson product moment (r) and the Spearman rank (rs) correlation coefficients between the PT and PAI were highly significant for both muscle groups in the uninjured (r = .81-.97, rs = .77-.97) as well as in the MCL deficient (r = .77-.97, rs = .75-.95 knees. The results were the same between the PT and AP (uninjured knee: r = .83-.98, rs = .82-.98; MCL deficient knee: r = .78-.97, rs = .76-.97). In both knees and in both muscle groups the correlation coefficients increased toward the highest speed of the isokinetic movement, obviously because the PAI and AP were registered at that speed. In conclusion, concerning MCL deficient or uninjured knees the PAI or AP analysis may offer little additional information about thigh muscle function to that attained by more simple measurement, the PT analysis.