EFFECTS OF BODY-WEIGHT UNLOADING AND ORTHOTIC INSERTS ON PLANTAR PRESSURE DURING TREADMILL AMBULATION

Abstract

2091 Purpose: Traditional methods of reducing pressure on the plantar surface of the foot to decrease the risk of ulceration have focused on the use of orthotic inserts and shoe modifications. Current research is exploring the use of harness supported treadmill systems as an alternative method of reducing plantar pressures during ambulation in the clinical setting. The purpose of this study was to determine whether the combination of these techniques further reduces pressure under the metatarsal heads during ambulation. Subjects: Eighteen adult volunteers (mean age=27 yrs., mean wt.=167 lbs.) in generally good health with no known foot pathologies or abnormalities participated. Methods: Subjects ambulated on a treadmill at a self-selected speed with 0%, 20%, and 40% body weight support, with and without the use of orthotic inserts. Plantar pressures (PSI) were measured under the first and second metatarsal heads under each of the six trial conditions. Results: Unloading alone significantly reduced (p ≤ .05) plantar pressures by 28.6% at 20% body weight unloaded (BWU) and 57% at 40% BWU. Significant reductions were also found with the use of metatarsal pads at 0%, 20%, and 40% BWU yielding reductions of 26.7%, 50%, and 73%, respectively. Discussion: The greatest amount of pressure reduction was found with a combination of 40% unloading with a metatarsal pad. These findings suggest that individuals prone to pressure induced ulcers may benefit from combined use of unloading and orthotics.