Optimising backpack hip belt design: an ergonomic perspective on gait mechanics.

Backpack hip belts help redistribute weight but may limit pelvis and trunk transverse plane rotations. This study explores how hip belt designs influence gait mechanics. Sixteen participants walked under three backpack conditions: a movable hip belt, a spring cross frame and a fixed hip belt, each carrying a 13 kg load. Kinematic data was collected using IMU sensors, and muscle activity with electromyography. The findings reveal that both the spring cross-frame and movable hip belt designs preserve neutral pelvic mobility relative to normal gait. However, only the cross-frame design exhibited a coordination pattern between the pelvis and trunk similar to natural walking, possibly due to its ability to control trunk rotational range of motion (ROM). Additionally, the cross-frame mechanism led to lower erector spinae muscle activation compared to the fixed-frame hip belt. This study emphasises the crucial role of hip belt design in influencing trunk and pelvic movement during walking.