Point of insertion is defined as?

• A. The location where a muscle is attached to a bone that will cause motion when the muscle contracts
• B. The origin of a muscle
• C. Where the tendon attaches to bone that does not move
• D. The muscle belly

Answer: (A)

The idea being tested is how a muscle produces movement through its attachments. The point of insertion is the site where the muscle attaches to the bone that moves when the muscle contracts. When the muscle shortens, it pulls on this moving bone, bringing it toward the origin and causing the joint to move. For example, the biceps muscle has its origin on the scapula and humerus and its tendon inserts into the radius; when the biceps contracts, the radius moves and the elbow bends. The origin, by contrast, is the attachment that typically remains relatively fixed during contraction, and the muscle belly is just the thick, central part of the muscle.