Abstract
In this study, we address to quantify the relationship between the significant arm-clutch loading, leg restriction and motor paralysis, and analyze lumbar joint trajectories in the orthotic gait of paraplegic subjects and the ordinary and orthotic gaits of a normal subject using an inverted pendulum model. For the leg restriction, the trajectories are located in front of an equilibrium point of the inverted pendulum, and the loading is higher due to the influence of gravity moment. Comparing the trajectory of paraplegic and normal gait with orthosis in horizontal plane, the trajectory in the paraplegic subjects was rectilinear shape, while that in normal subject was curved in the direction to the equilibrium point. The loading is lower in the curved trajectory than in the straight trajectory because of the trade-off between gravity and inertia. These results suggest that the increase of the distance between the trunk movement and the equilibrium point of the inverted pendulum result in the significant loading due to the leg restriction and motor paralysis in orthotic gait of paraplegics.
