Patellofemoral Compressive Force and Stress During the Forward and Side Lunge With and Without a Stride

Abstract

PURPOSE: Because weight bearing lunge exercises are frequently employed during patellofemoral rehabilitation, the purpose was to determine patellofemoral compressive force and stress during forward and side lunge exercises. METHODS: Eighteen subjects used their 12 repetition maximum weight while performing forward and side lunges with and without a stride. EMG, force platform, and kinematic variables were input into a biomechanical model, and patellofemoral compressive force and stress were calculated as a function of knee flexion angles. RESULTS: Between 0-60° knee flexion angles patellofemoral compressive force and stress were greater in the forward lunge with stride compared to the side lunge with stride. Between 0-50° knee flexion angles patellofemoral compressive force and stress were significantly greater in the forward lunge with stride compared to the forward lunge without stride. Patellofemoral compressive force and stress increased progressively as knee flexion angles increased. CONCLUSIONS: More functional knee flexion angles between 0-50° may be appropriate during the early phases of patellofemoral rehabilitation due to lower patellofemoral compressive force and stress during this range compared to higher knee flexion angles between 60-90°. Moreover, when the goal is to minimize patellofemoral compressive force and stress, it may be prudent to employ the side lunge compared to the forward lunge, and the forward lunge without stride compared to the forward lunge with stride, especially in early phases of patellofemoral rehabilitation. Understanding differences in patellofemoral compressive force and stress among lunge variations help clinicians prescribe safer and more effective exercise interventions.