Prosthetic Feet

Axtion DP foot and Harmony pump
(Courtesy of Otto Bock HealthCare)

A prosthetic foot is made of metal, plastic or a combination of the two. There are a lot of reasons from birth defects to accidents which cause a loss of a person's foot. There are various kinds of prosthetic feet available for amputees based upon the patient's circumstances.

A prosthetic foot can be attached to a person's ankle or calf to compensate for missing foot. In certain cases where a part of a person's foot is missing, a partial foot may attach to the remaining part of a person's foot to compensate for missing parts.
There are five basic functions of the prosthetic foot:

  • Replace lost muscle function,
  • Provide a stable, weight-bearing surface,
  • Absorb shock during movement,
  • Replicate anatomic joint, and
  • Restore cosmetic appearance of the limb.

There are two broad categories of prosthetic feet: energy-returning feet or non-energy-returning feet.

(Courtesy of Otto Bock HealthCare)

Non energy returning feet include solid-ankle, cushioned-heel (SACH) foot and the single-axis foot. The SACH foot mimics ankle plantar flexion which allows for a smooth gait. This prosthetic is a low-cost and low-maintenance foot for a sedentary patient who has had a BKA or an AKA. The single-axis foot adds passive plantar flexion and dorsiflexion, which increase stability during the stance phase. These are commonly used for patients with transfemoral amputation if knee stability is desired.

energy returning foot

Energy-returning feet assist the body's natural biomechanics and allows for greater cadence or less oxygen consumption. The multiaxis foot and the dynamic-response foot are members of this family. The multiaxis foot adds inversion, eversion, and rotation to plantar flexion and dorsiflexion; it handles uneven terrain well and is a good choice for individuals with minimal-to-moderate activity level. The dynamic-response foot is commonly used by young, active persons and by athletic individuals. The forefoot acts like a spring, compressing in the stance phase and rebounding at toe-off.