I recently attended a product information session on Endolite feet presented by John Ross, a prosthetist from the UK. John introduced us to the Elan microprocessor foot. After the session I looked into what other microprocessor feet were available and found quite a few other interesting feet and have included a few of them below.
Unlike conventional prosthetic feet, which generally have a fixed ankle, microprocessor feet allow for the ankle position to be changed without the need of a ground reaction force. The ankle is controlled by the microprocessor which adapts to type of ground to make walking more energy efficient and safer for the user. This means that the ankle is able to automatically be moved into the position that you need, whether you are going up or down a hill, sitting in a chair or climbing the stairs.
The Elan by Endolite incorporates a carbon fibre foot with a microprocessor controlled hydraulic ankle unit. Sensors in the foot continuously monitor the environment and change the characteristics of the foot and ankle to offer the most energy efficient response to accommodate slopes and stairs. The microprocessor adjusts the hydraulic ankle unit in order to control dorsiflexion (toe-up) and plantarflexion (toe-down) of the ankle unit. This aids in optimising the loading of the carbon fibre foot on varying terrains, allowing it to store and release energy more efficiently through the gait cycle.
Ossur’s Proprio Foot refers to proprioception, the sense of where a limb is in space, which enables the human body to react to its environment. It incorporates a carbon fibre foot with a microprocessor controlled hydraulic ankle unit. Sensors in the Proprio foot determine the direction and speed of the foot movement. The microprocessor then controls the angle of the ankle during swing phase (when the foot is off the ground) to help reduce falls. It also makes adjustments to accommodate differences in force, speed and terrain during stance phase (when the foot is on the ground) to create a more efficient gait. The Proprio foot will also accommodate a variety of shoes as it can be preset for shoes with different heel heights.
The Power Foot by iWalk with the BiOM ankle is the only prosthetic foot to provide active propulsion during the gait cycle. The Power Foot replaces the missing calf muscle and the Achilles tendon and allows the amputee to actively push off the ground resulting in the most energy efficient gait possible. The Power Foot generates energy for walking by using multiple springs and a small battery-powered motor.
Other microprocessor feet that are currently available or being trialled include the Raize by Fillauer and Magellan by Orthocare Innovations. As with any prosthetic component, these feet are not suitable for every amputee, and there may be something else more suitable for you. However, if you are interested in finding out more information on any of these feet, or other components, ask your prosthetist on your next visit.