Absence of visual feedback during standing alters force direction/location ratio

Upright human standing requires stabilization of both translational and rotational degrees-of-freedom in the sagittal plane that is primarily accomplished by coordination of joint torques at the hip, knee, and ankle. Those torques produce the ground-on-foot force (F) which has recently been shown to exhibit an interesting covariation across time between center-of-pressure (CP) and direction (θF) that is geometrically characterized as intersecting at a point (IP) with height that varies with frequency. Here we show that IP is elevated with the removal of vision and discuss possible implications for understanding human standing.