Abduction

Movement of a limb away from the midline of the body. Opposite of Adduction .

Achilles Tendon

This tendon, at the back of the lower leg, attaches the calf muscles (gastrocnemius & soleus) to the heel bone (calcaneus).

Acute

An injury having a sudden rapid onset – trauma. Opposite of Chronic .

Adduction

Movement of a limb towards the midline of the body. Opposite of Abduction .

Agonist

A term denoting a muscle in a state of contraction, with reference to its opposing muscle, or antagonist . Agonist muscles are also called prime movers.

Antagonist

A muscle opposing or resisting the action of another. Opposite of Agonist .

Anterior

Directed toward the front of the body. Opposite of Posterior .

Articulation

A joint. It is a joining or connecting together loosely, so as to allow motion between the parts.

Atrophy

A condition arising in the muscle after it has been cut off from its nerve supply or forced by injury to become inactive or immobilized. Opposite of Hypertrophy .

Avulsion

A forcible tearing away of a part or structure.

Axilla

The region also known as the armpit.