Patellofemoral joint loading during the forward and backward lunge

Area of Science:

• Biomechanics
• Human Movement Analysis
• Orthopedics

Background:

• The patellofemoral joint (PFJ) is susceptible to overload, leading to pain and dysfunction.
• Understanding the biomechanical demands of common exercises like lunges is crucial for injury prevention and rehabilitation.
• Different lunge variations may impose distinct loads on the PFJ, necessitating comparative analysis.

Purpose of the Study:

• To compare patellofemoral joint (PFJ) loading between Forward Lunges (FL) and Backward Lunges (BL).
• To quantify key biomechanical parameters influencing PFJ stress during these movements.

Main Methods:

• A repeated measures design was employed in a university biomechanics laboratory.
• Twenty asymptomatic female participants performed six trials of both Forward and Backward Lunges.
• Three-dimensional motion capture and force platforms were utilized to derive quadriceps force, PFJ reaction force, PFJ stress, and knee flexion angles via a musculoskeletal model.

Main Results:

• Significant differences in PFJ loading variables and knee joint angles were observed between FL and BL, and between the downward and upward phases of movement.
• The Forward Lunge (FL) demonstrated higher quadriceps force, PFJ reaction force, and knee flexion angles compared to the Backward Lunge (BL).
• Increased PFJ loading rate and reduced forward trunk tilt were noted during the FL.

Conclusions:

• The Forward Lunge (FL) imposes greater patellofemoral joint (PFJ) loading compared to the Backward Lunge (BL).
• The findings suggest that Backward Lunges (BL) may be a potentially less stressful alternative for individuals experiencing patellofemoral pain (PFP).
• Further investigation in populations with patellofemoral pain (PFP) is warranted to confirm the clinical utility of Backward Lunges (BL).