A system and method associated with the movement of a limb. In one example, the system, such as a prosthetic or orthotic system, includes an actuator (116) that actively controls, or adjusts, the angle between a foot unit (104) and a lower limb member (102). A processing module may control movement of the actuator (116) based on data obtained from a sensor module. For instance, sensing module data may include information relating to the gait of a user and may be used to adjust the foot unit to substantially mimic the movement of a natural, healthy ankle. The system may further accommodate, for example, level ground walking, traveling up/down stairs, traveling up/down sloped surfaces, and various other user movements. In addition, the processing module may receive user input or display output signals through an external interface.; For example, the processing module may receive a heel height input from the user.