Kinematics and kinetics of 2 styles of partial forward lunge.

OBJECTIVE To evaluate the anterior shift of the body's center of gravity (CG) and the associated inertial forces produced by 2 styles of a partial forward lunge. SETTING Gait-analysis laboratory of a research institution. PARTICIPANTS 10 healthy volunteers. INTERVENTION 3 trials of each lunge. MAIN OUTCOME MEASURES Kinematic data were collected, and inertial reaction forces were resolved into net compressive and shear forces using an inverse dynamic model. RESULTS Significantly (P < .001) greater anterior translation of the CG was found with an arms-in-front v arms-across-chest lunge style. No significant differences were found between the average peak inertial compressive and shear forces of the 2 styles (427 +/- 184 N v 426 +/- 187 N, -536 +/- 113 N v -538 +/- 127 N). CONCLUSION Anterior translation of the CG was larger with the arms-forward partial-lunge position, creating increased balance demands. Both styles produced clinically safe (posteriorly directed) inertial shear forces, with greater anterior CG shift with the arms-forward style.