The Effect of Passive Prosthetic Feet on the Performance of Activities of Daily Living: A Preliminary Investigation

Abstract

The human foot and ankle joints provide substantial range of motion that allow for performance of everyday tasks, such as walking, sitting, and reaching. Lower-limb prosthetic device users (PDUs) often cannot achieve this same range of motion because most commercially available passive prosthetic devices have fixed ankle and toe joints. Many PDUs report having issues completing daily tasks. This preliminary study aims to characterize PDUs performing daily tasks to identify differences and deficiencies that could lead to overuse injuries or joint degeneration. Motion capture and force plate data were collected on three unilateral PDUs and two able-bodied controls while performing tasks such as standing up from a chair, lifting a box off the ground, squatting, reaching to pick up an item, and lunging. Ankle angle, metatarsophalangeal (toe) angle, and vertical ground reaction force were measured. The ground reaction force results showed asymmetrical loading during the sit-to-stand task in the highest and lowest chair height, squatting, and lifting. Compared to the control group, in which both participants exhibited generally symmetrical forces, PDUs loaded more of their weight on their intact limb. PDUs generally exhibited a much lower ankle and toe range of motion on the prosthetic side versus intact. These results can be used to inform prosthetic device design to facilitate activities of daily living.