Most stroke patients lose their forefoot rocker function. The purpose of this study was to develop and
evaluate an orthosis (HUS-AFO) which elevates the heel of the paralyzed side during the single-leg support phase
period and functions as a forefoot rocker. The HUS-AFO has a four-link mechanism structure and assists heel elevation
by a virtual rocker axis (HUS axis) located proximally to the MP joint and a compression spring located at the lateral
side of the orthosis. A HUS device is incorporated into the sole of a short leg orthosis with a dorsiflexion resistive
function to increase the plantar flexion moment of the ankle joint during walking. In addition, it was found that the
HUS-AFO assists in moving forward the center of pressure of the foot (COP), and that the heel is elevated during the
single-leg support phase period when the COP forward front of the HUS axis is located proximally to the MP joint.
