In humans, the toes are important for stability while standing. We aim to elucidate the role of the toes in posture control by examining the relationship between the action of the flexor muscles and the center of pressure (COP) positions in the standing posture.
The subjects were 16 healthy young adults who were free of musculoskeletal and neurological disorders. We measured the toe plantarflexion movements, COP positions, and floor reaction force components in the standing and forward loading postures.
In subjects with more anteriorly-located COP positions during the forward body shift, the toe flexion angle was greater. Moreover, as the COP position in the static standing posture was more anteriorly located, the subjects were more likely to flex their toes with the interphalangeal joint extended.
Our findings suggest that the ability to flex the toes with extended interphalangeal joints affects stability in the static standing position. In addition, the toe flexion angles and force of pushing against the floor affect dynamic balance.