Any muscle that extends joints.
Muscle that, when flexed, causes extension of a joint, or straightening of an arm or leg.
A muscle that extends a part of the body.
Muscles that straighten the wrist, hand, and fingers to form a straight line.
An extensor muscle is any muscle that operates a joint to extend or straighten a limb. The triceps muscle in the arm, which straightens the elbow, serves as an example of an extensor muscle.