Abduction

Abrasion

Abscess

Localized accumulation of pus and necrotic tissue.

Anterior Cruciate Ligament (ACL)

The ligament, located in the center of the knee, that controls rotation and forward movement of the tibia.

Active inhibition

Technique whereby an individual consciously relaxes a muscle prior to stretching it.

Active movement

Joint motion performed voluntarily by the individual through muscular contraction.

Acute injury

Injury with rapid onset due to traumatic episode, but with short duration.

Adduction

Movement of a body segment toward the midline of the body.

Adhesions

Tissues that bind the healing tissue to adjacent structures, such as other ligaments or bones.

Ambulation

Moving or walking about.

Ambulatory aid

Assistance used to help an injured individual walk, such as crutches, a cane or a walker.

Analgesia

Conscious state in which normal pain is not perceived, such a a numbing or sedative.

Analgesic

Anatomical snuff box

Region directly over the scaphoid bone bounded by the extensor pollicis brevis medially and the extensor pollicis longus laterally.

Anesthesia

Partial or total loss of sensation.

Anesthetic

Ankylosing spondylitis

A disease that affects the spine, causing the bones of the spine to grow together.

Antagonist muscles

Muscles that oppose or reverse a particular movement.

Antalgic gait

Walking with a limp to avoid pain.

Aponeurosis

A fibrous sheet or tendinous expansion connecting a muscle to the part it moves.

Apophysis

An outgrowth or projection on a bone where muscles attach.

Apophysitis

Inflammation of an apophysis.

Arthalgia

Severe joint pain.

Arthritis

Inflammation of a joint, usually accompanied by pain and swelling.

Arthrogram

Diagnostic tool whereby a radiopaque material is injected into a joint to facilitate taking a radiograph.

Arthroscopy

Diagnostic tool whereby the inside of a joint is viewed through a small camera lens (arthroscope) to facilitate surgical repair of the joint and/or joint structures.

Aseptic necrosis

The death or decay of tissue due to a poor blood supply in the area.

Aspiration

Removing fluid by suction from a body area, such as a joint cavity.

Atrophy

A wasting away or deterioration of tissue due to disease, disuse, or malnutrition.

Avascular

Devoid of blood vessels.

Avascular necrosis

Death of tissues due to insufficient blood supply.

Avulsion

A tearing away or forceful separation of a body part or structure.

Axial loading

Loading directed along the long axis of a body.