Ten cadaver legs were mounted on a loading frame, and normal values for
quadriceps excursion and tibial force were established with a constant
quadriceps tension. The mean excursion of the quadriceps was 66.2 +/- 5.51
millimeters from zero to 90 degrees of knee flexion. After examining each
10-degree increment of motion we found that the maximum excursion of the
quadriceps (9.49 +/- 1.35 millimeters) occurred between 30 and 40 degrees.
The minimum excursion of 5.40 +/- 0.67 millimeters was found between 80 and
90 degrees of knee flexion. Incremental excursion of the quadriceps during
10-degree increments of knee flexion showed a correlation coefficient of
0.94 when compared with mean tibial torque (p less than 0.001).
Patellectomy decreased excursion of the quadriceps to 51.3 +/- 1.30
millimeters from zero to 90 degrees of knee flexion. Torque was decreased
by roughly 40 per cent of maximum from zero to 40 degrees of knee
flexion.