The purpose of this study was to assess and describe the status of
twenty-four patients with a diagnosed tear of the anterior cruciate
ligament who participated in a non-operative program of rehabilitation
emphasizing strengthening of the hamstrings. The knees were evaluated by
testing stability, strength, and range of motion; by roentgenographic
examination; and by the patient's level of participation in sports. The
patient's uninjured knee was used for comparison. The results showed a high
incidence of anterior instability, but no significant differences in
degenerative changes or range of motion. All patients returned to some
sports participation, with fourteen (59 per cent) returning to their full
preinjury level of participation. Higher levels of sports participation
were found in the patients whose hamstrings strength was equal to or more
than their quadriceps strength.