A new method for the determination of the characteristic shape of an isokinetic quadriceps femoris muscle torque curve

Department of Physical Therapy, University of California, Los Angeles Medical Center 90024-1704.

It has been suggested that visual analysis of isokinetic quadriceps femoris muscle torque curve (TC) shapes may have potential use in the diagnosis and prognosis of knee pathologies. The primary purpose of this pilot study was to develop a method for analyzing the shape of an isokinetic TC. Our method normalizes and averages the TC, and then uses curvilinear analysis of the TC shape to aid in diagnosis and prognosis. For demonstration, the method was applied to isokinetic quadriceps femoris muscle TC data collected using a LIDO digital dynamometer from 25 healthy volunteer subjects and retrospectively acquired from the uninvolved limbs of 37 patients with unilateral knee pathologies. The preliminary results revealed (1) that a common quadriceps femoris muscle TC shape existed for the volunteer group at 60 degrees and 180 degrees/s; (2) that the uninvolved limbs of the patient group exhibited the same shape at 60 degrees/s, but not at 180 degrees/s; and (3) that the quadriceps femoris muscle TC shape demonstrated no significant differences with respect to limb dominance or gender for either group. Further testing of this quantitative method on a larger sample is needed to determine its usefulness in the analysis and implications of TC shape concerning pathology and diagnosis.