ABC CPO key terms

Surgical removal of the leg above the knee joint, through the femur. The residual limb must support sitting and prosthetic weight bearing, so socket design and ischial containment are central concerns.

Surgical removal of the leg below the knee, preserving the knee joint. The residual tibia and fibula transfer load through the socket, and patellar tendon bearing designs are common.

The portion of the limb remaining after amputation. Its shape, volume, sensation, and skin integrity determine how a prosthesis is fit and how often the socket must be adjusted.

The hollow interface that receives the residual limb and connects it to the rest of the prosthesis. Fit, suspension, and load distribution all depend on socket shape and material.

A soft or gel layer worn against the skin inside a prosthetic socket. Liners cushion pressure, protect skin, and often provide suspension through suction or a locking pin.

The method that holds a prosthesis onto the residual limb and prevents it from sliding off during swing phase. Common systems include suction, pin locks, sleeves, and belts.

A suspension approach in which air is expelled from the space between liner and socket, creating a seal that holds the prosthesis on. It requires a well-fitting, airtight socket and stable limb volume.

A transtibial socket design that concentrates load on pressure-tolerant areas such as the patellar tendon while relieving pressure-sensitive spots like the tibial crest and fibular head.

A transfemoral socket design that encloses the ischial tuberosity and ramus within the socket brim. It improves stability and rotational control compared with designs that seat the ischium on top of the brim.

The mechanical joint of a transfemoral prosthesis that substitutes for the anatomic knee. Designs range from single-axis to microprocessor-controlled units that adjust resistance to walking speed.

The ability of a prosthetic knee to resist buckling and support body weight while the foot is on the ground. It is achieved through alignment, friction, or microprocessor braking.

The mechanism that regulates how quickly the prosthetic knee flexes and extends while the foot is off the ground. It affects toe clearance, cadence, and the smoothness of gait.

The distal component that replaces the anatomic foot, providing a base of support and simulating ankle motion. Categories include solid ankle cushion heel, single-axis, and energy-storing designs.

A prosthetic foot that deflects under load and returns energy during push-off, assisting walking at faster speeds. It is often chosen for active users and higher functional levels.

The spatial relationship among socket, knee, and foot set during fitting. Bench and dynamic alignment adjust stability, comfort, and gait efficiency for the individual user.

Structured practice in walking with a prosthesis, including weight shifting, step length, balance, and safety skills. It follows fitting and progresses from parallel bars to community ambulation.

Monitoring and controlling changes in residual limb size, which fluctuate with swelling, activity, and time since surgery. Strategies include shrinkers, liner adjustments, and socket refits.

Pain perceived in the portion of the limb that has been amputated. It is distinct from residual limb pain and may be managed with medications, mirror therapy, or desensitization techniques.

A progressive technique of applying graded touch, tapping, or texture to a sensitive residual limb so that it tolerates contact. It prepares the limb for socket wear.

A device replacing all or part of an arm, ranging from passive cosmetic hands to body-powered hooks and myoelectric hands. Component choice depends on amputation level and user goals.

An upper limb prosthesis operated by shoulder and cable movement that opens or closes a terminal device. It offers durable, proprioceptive control without batteries.

An upper limb prosthesis whose terminal device is driven by electrical signals from residual muscle contractions detected by surface electrodes. It requires training and battery maintenance.

An externally applied device that supports, aligns, prevents, or corrects deformity or improves function of a body segment. Orthoses are named by the joint or region they cross.

A brace crossing the ankle and foot that controls ankle motion and provides mediolateral stability. It is commonly used for foot drop and after stroke or nerve injury.

A long leg brace crossing the knee, ankle, and foot, used to stabilize the knee and lower limb. It is often prescribed for knee instability, quadriceps weakness, or post-polio deformity.

Weakness or paralysis of ankle dorsiflexion that prevents lifting the toes during swing. An ankle-foot orthosis is a common intervention to restore toe clearance and reduce falls.

A trunk brace extending from the upper thoracic spine to the sacrum, used to limit spinal motion and support posture. It is prescribed for fractures, scoliosis, and postoperative protection.

A lateral curvature of the spine that may be treated with observation, bracing, or surgery depending on severity and growth status. Bracing aims to slow progression during skeletal growth.

A neck brace that limits cervical spine motion to protect injured structures or relieve pain. Rigid collars provide more restriction than soft collars but still allow substantial movement.

A biomechanical principle in which forces applied at three points create a bending moment that corrects or controls a deformity. It underlies many orthotic and spinal brace designs.

A design in which the brace shell contacts the limb over its full surface rather than at isolated pads. It distributes pressure more evenly and improves comfort and control.

The way load is spread across the skin and underlying tissues by a socket or orthosis. Uneven or excessive pressure can cause skin breakdown, so relief areas are built into designs.

An abnormal walking pattern such as circumduction, vaulting, or excessive trunk lean. Identifying the deviation helps determine whether prosthetic or orthotic adjustment is needed.

A classification of a prosthesis user's walking potential, from limited household ambulation to high-impact activity. It guides component selection such as foot and knee type.

A fixed shortening of soft tissue across a joint that limits range of motion, often after prolonged immobility or amputation. Proper positioning and stretching help prevent it.

An elastic garment worn over a residual limb to reduce swelling and shape the limb for prosthetic fitting. Consistent wear supports stable socket fit.

The component at the end of an upper limb prosthesis that substitutes for the hand, such as a hook or cosmetic hand. It may be passive, body-powered, or electrically powered.

The material or layer between the body and a device, such as a liner in a socket or padding under an orthosis. Good interface design protects skin and improves tolerance.