The relationship between peak torque and work of the quadriceps and hamstrings after knee injury

The purpose of the present study was to assess the relationship between the isometric and isokinetic peak torques (speed of movement 0, 60, 180 deg/sec) and the total work output of multiple contractions (180 deg/sec) of the quadriceps and hamstrings in 68 patients having seven years earlier a hemarthrotic knee injury. At every test speed the Pearson product moment (r) and the Spearman rank (rs) correlation coefficients between the peak torque and the total work were highly significant (p less than 0.001) for the quadriceps and hamstrings in the uninjured (r = 0.74-0.92, rs = 0.75-0.93) as well as in the injured (r = 0.83-0.93, rs = 0.84-0.92) knees. All correlation coefficients were higher at the highest speed (180 deg/sec) of the isokinetic test (r = 0.90-0.93, rs = 0.91-0.93) than at the other speeds (0 and 60 deg/sec) (r = 0.74-0.88, rs = 0.75-0.89) obviously since the total work was registered at that speed. In conclusion, in injured or healthy knees the isokinetic total work analysis offers little additional information to that attained by more simple measurements, the peak torque recordings.