The purpose of this study was to determine whether the Genesis II foot enhanced function in unilateral belowknee amputees in comparison with the Seattle foot. Ten unilateral amputees were tested with gait analysis, energy consumption, and agility tests wearing the Seattle foot and the Genesis foot in conjunction with a subject satisfaction survey. Gait analysis found no significant differences in gait parameters, although peak dorsiflexion was increased with the Genesis foot in comparison with the Seattle foot. The Genesis foot also had an increase in power absorption and generation in comparison with the Seattle foot. No significant differences were found in energy consumption and agility tests. Subjects found the Genesis foot to excel in the ability to go up hills, in propulsion, and in maneuverability on uneven ground in comparison with the Seattle foot. The increased motion and power generation found in subjects wearing the Genesis foot appears to enhance function during walking and running. These findings correlated well with subject impression of foot function.