Peak Patellofemoral and ACL/PCL Forces While Performing the Forward Lunge Exercise With Varying Techniques

Abstract

PURPOSE: To compare peak patellofemoral and ACL/PCL forces among varying lunging techniques involving lunging with a long and short stride both on flat ground and up to a 4 inch platform. METHODS: Sixteen male and female subjects (mean bodyweight 678N, 69.1 kg mass; 175.9 cm height; 28.9 years old) using bodyweight only performed a forward lunge with a long stride (shank vertical at bottom position) and a short stride (1/2 the long stride distance) on flat ground and up to a 4 inch platform. Force platform and video data were collected and input into a biomechanical model, and peak patellofemoral and ACL/PCL were calculated as a function of knee angle. A One-Way Repeated measures ANOVA assessed significant differences among lunging techniques (p<0.05). RESULTS: Peak patellofemoral force occurred between 79°-96° knee angles and was significantly greater (p<0.001) with a short stride lunge on flat ground (1668±479N) and up to a 4 inch platform (1553±580N) compared to lunging with a long stride lunge on flat ground (1193±512N) and up to a 4 inch platform (1061±523N), but no significant differences in peak patellofemoral force were found between the two short stride lunges (p=0.99) and between the two long stride lunges (p=0.99). Peak ACL force occurred between 7°-12° knee angles and was not significantly different (p=0.70) among any of the lunging techniques. Peak PCL force occurred between 62°-83° knee angles and was significantly greater (p<0.001) with a long stride lunge on flat ground (554±220N) and up to a 4 inch platform (609±265N) compared to lunging with a long stride lunge on flat ground (402±114N) and up to a 4 inch platform (458±145N), but no significant differences in peak PCL force were found between the two short stride lunges (p=0.99) and between the two long stride lunges (p=.99). CONCLUSIONS: Lunge technique variations did affect peak patellofemoral and cruciate ligament forces. Compared to a long stride lunge, lunging with a short stride, which caused the knees to translate forward approximately 8 cm beyond the knees at bottom lunge position, resulted in greater peak patellofemoral force but less PCL force. Lunging technique variations did not affect peak ACL force. There were no patellofemoral or PCL differences in peak force between the two long stride lunges or between the two short stride lunges.