Purpose: To compare cruciate ligament forces during wall squat and one-leg squat exercises.
Methods: Eighteen subjects performed the wall squat with feet closer to the wall (wall squat short), the wall squat with feet farther from the wall (wall squat long), and the one-leg squat. EMG, force, and kinematic variables were input into a biomechanical model using optimization. A three-factor repeated-measure ANOVA (P < 0.05) with planned comparisons was used.
Results: Mean posterior cruciate ligament (PCL) forces were significantly greater in 1) wall squat long compared with wall squat short (0°-80° knee angles) and one-leg squat (0°-90° knee angles); 2) wall squat short compared with one-leg squat between 0°-20° and 90° knee angles; 3) wall squat long compared with wall squat short (70°-0° knee angles) and one-leg squat (90°-60° and 20°-0° knee angles); and 4) wall squat short compared with one-leg squat between 90°-70° and 0° knee angles. Peak PCL force magnitudes occurred between 80° and 90° knee angles and were 723 ± 127 N for wall squat long, 786 ± 197 N for wall squat short, and 414 ± 133 N for one-leg squat. Anterior cruciate ligament (ACL) forces during one-leg squat occurred between 0° and 40° knee angles, with a peak magnitude of 59 ± 52 N at 30° knee angle. Quadriceps force ranged approximately between 30 and 720 N, whereas hamstring force ranged approximately between 15 and 190 N.
Conclusions: Throughout the 0°-90° knee angles, the wall squat long generally exhibited significantly greater PCL forces compared with the wall squat short and one-leg squat. PCL forces were similar between the wall squat short and the one-leg squat. ACL forces were generated only in the one-leg squat. All exercises appear to load the ACL and the PCL within a safe range in healthy individuals.