Biomechanical Properties Required for the Reduction of Knee Adduction Moment Using Gait Modification in Individuals With Obesity

Abstract

Objective

To investigate the effects of gait modification on the knee lever arm (KLA) in individuals with obesity.

Design

This study was designed as a retrospective, cross-sectional, observational study to investigate the impact of gait modifications on knee joint loading in individuals with obesity. A convenience sample was used, and no formal sample size calculation was performed.

Setting

Single university hospital.

Participants

Fifty-three individuals (N=53) with obesity who had no history of lower-limb surgery, musculoskeletal disorders, or neuromuscular diseases affecting gait.

Interventions

Interventions: Not applicable.

Main Outcome Measures

Three-dimensional gait analyses were performed in individuals with obesity under 3 conditions: walking at a comfortable speed, with their toes outward (toe-out gait), and with a wider step width (wide-base gait). The peak knee adduction moment (KAM), area under the curve of KAM during stance (KAM impulse), and KLA were measured. Considering the relative position between foot placement and the center of gravity by gait modifications, the KLA was divided into the mediolateral shift of the center of pressure (center of pressure component of KLA [KLA-COP]) and the mediolateral tilt of the ground reaction force vector (tilt component of KLA [KLA-tilt]).

Results

Wide-base gait significantly reduced peak KAM, KAM impulse, KLA, and KLA-COP but increased the KLA-tilt, whereas the toe-out gait did not significantly reduce these parameters compared with other conditions. In the wide-base gait, the change in peak KAM was significantly correlated with changes in the hip abduction angle (r=−.66).

Conclusions

The results show that reducing the KLA-COP and increasing the KLA-tilt with a lateral shift in foot placement acted as abduction and adduction moments, respectively. In particular, changing the hip kinematics can enhance the effects of gait modification in individuals with obesity.