Single leg aerobic capacity and strength in individuals with surgically repaired anterior cruciate ligaments.

Objectives: Compare single-leg aerobic capacity and strength differences between the surgically repaired ACL leg (injured) and the uninjured leg.

Design: Cross-sectional study.

Setting: Laboratory.

Participants: Eight participants (5 female, 3 male, age = 23 ± 3.5 y, mass = 72.3 ± 17.3 kg, height = 169.7 ± 9.4 cm) that returned to play from ACL surgery between six and 18 months.

Main Outcome Measures: Participants performed an aerobically-based, single-leg cycling protocol to determine maximum oxygen consumption, ventilatory threshold, heart rate, rating of perceived exertion, and maximal watts cycled. Participants also performed isokinetic knee flexion and extension on a dynamometer to assess peak torque, total work, work fatigue, and power.

Results: There were no statistical differences in single-leg aerobic capacity or strength outcomes between the injured and uninjured legs.

Conclusions: Individuals who have had an ACL surgically repaired six to 18 months after return to play do not appear to have aerobic capacity or strength deficits between the injured leg and uninjured leg.