Patellofemoral Joint Loading during the Forward and Backward Lunge

Abstract Objective To examine patellofemoral joint (PFJ) loading in two lunge movements: Forward Lunge (FL) and Backward Lunge (BL). Design Repeated Measures Setting University Biomechanics Laboratory Participants 20 asymptomatic females Main Outcome Measures Six trials of two lunge movements (FL and BL) to a depth of 75% of leg length were performed. 3-D motion capture and force platforms were used to collect data as input into a musculoskeletal model to determine quadriceps force, PFJ reaction force, PFJ stress, and knee flexion angle. Results Multivariate analysis indicated differences in PFJ loading variables and joint angles between the lunge movements (Forward vs. Backward) and phases (Down vs. Up). Quadriceps force, PFJ reaction force, and knee flexion angle were larger in the FL movement and Up phases. PFJ loading rate was greater in the FL movement along with a lower forward trunk tilt. Conclusion The FL produced greater PFJ loading variables compared to the BL. Further research is needed to examine a population of individuals who have patellofemoral pain (PFP) to see if their symptoms may be reduced when using the BL.