Biomechanical comparison of forward and lateral lunges at varying step lengths

Aim. Lunges are commonly included in rehabilitation and strength training programs; however limited information regarding differences between lateral and forward lunges with varying step lengths in young adults exists. The current study compared sagittal plane joint kinematics and kinetics between forward and lateral lunges using self-selected and standardized (60% height) step lengths. Methods. Thirty-two young adults (16 men, 16 women) completed six lunges of each direction/distance combination while stepping (dominant) limb ankle, knee, and hip peak flexion and net joint extensor moment impulse were quantified. Results. While lateral direction (P=0.063) step lengths were statistically equal between self-selected and standardized lunges, forward self-selected distances were 10% less than the standardized (P<0.001). Compared to forward lunges, lateral lunge ankle flexion was 83.5% greater (P<0.001) for standard and 55.3% greater (P<0.001) for self-selected distances. Knee flexion was 12.8% greater (P<0.001) during forward lunges compared to lateral lunges, with no significant hip direction differences. Ankle impulse during the lateral lunges was 71.3% greater (P<0.001) compared to forward lunges. Lateral lunge knee impulse was 47.6% greater (P<0.001) for standardized and 16.9% greater (P=0.001) for self-selected distances compared to forward lunges. Forward lunge hip impulse was 64.5% greater for the standardized (P<0.001) and 44.6% greater for self-selected (P<0.001) distances compared to lateral lunges. Conclusion. Forward lunges, particularly using 60% body height step length, appear to place the greatest demands on the hip extensors. Lateral lunges prompted greater ankle flexion and greater ankle and knee extensor kinetic contributions. These data provide rationale for lunge variation selection for young adults.