extension
movement of joints
Quick Summary
Extension is a type of joint movement that increases the angle between two body parts, effectively straightening a limb. For example, straightening the knee involves extension. This movement is often facilitated by extensor muscles, which are responsible for increasing the angle of a limb, such as straightening the elbow or knee. Other joint movements include flexion (decreasing the angle), abduction (moving away from the body's midline), adduction (moving toward the midline), rotation, and circumduction.12
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