In muscle anatomy, the origin is best described as the attachment that usually remains stationary during muscle contraction.

• A. The movable attachment
• B. The fixed attachment
• C. The insertion into bone
• D. The nerve supply

Answer: (B)

The moving part of a contraction pulls toward a fixed anchor. The end of the muscle that remains attached to the bone and doesn’t move much is the origin. This stationary attachment acts as the anchor, while the other end—the insertion—moves toward the origin as the muscle shortens. The nerve supply doesn’t define these attachments, and the insertion into bone is simply the moving end. So the attachment that stays still during contraction is the origin.