Contralateral pelvic drop during gait increases knee adduction moments of asymptomatic individuals

Purpose: The current study purpose was to investigate the effects of contralateral pelvic drop gait on the magnitude of the knee adduction moment (KAM) within asymptomatic individuals. Methods: 15 participants walked on a dual belt instrumented treadmill while segment motions and ground reaction forces were recorded. Participants completed typical gait trials and pelvic drop gait trials. The net external KAM was calculated using inverse dynamics. Peak and impulse were identified. Frontal plane hip abduction/adduction and pelvic drop were determined. Correlations and paired t-tests were used for statistical hypothesis testing (alpha = 0.05). Results: Peak hip adduction angle reached 4° (±6°) during pelvic drop trials compared to 0° (±6°) in the typical gait trials (p < 0.05) equating to 4° of pelvic drop. KAM impulse was higher in the pelvic drop trial (0.16 Nm s/kg ± 0.04) compared to the typical gait trial (0.13 Nm s/kg ± 0.05) (p < 0.001). Peak KAM was higher in the pelvic drop trial (0.55 Nm/kg ± 0.15) compared to the typical gait trial (0.40 Nm/kg ± 0.109) (p < 0.001). Correlations between change in KAM and change in hip adduction moment and pelvic drop were r > 0.80 (p < 0.001). Conclusion: Pelvic drop gait increased KAM peak and impulse. Results have implications for understanding relationships between frontal plane hip movement and the knee adduction moment during gait.