Which phrase most accurately describes a muscle’s insertion?

• A. The attachment site that remains relatively stationary when the muscle contracts
• B. The midpoint of the muscle belly where the greatest force is produced
• C. The connective tissue covering (fascia) that surrounds the entire muscle
• D. The attachment site that tends to move toward the origin during muscle contraction

Answer: (D)

Verified step by step guidance

1. Understand the basic terminology related to muscle attachments: the 'origin' and the 'insertion'. The origin is typically the fixed or less movable attachment site of the muscle, while the insertion is the attachment site that moves during muscle contraction.
2. Recognize that when a muscle contracts, it pulls on its insertion point, causing movement. Therefore, the insertion is the site that tends to move toward the origin.
3. Eliminate incorrect options by matching definitions: the attachment site that remains stationary corresponds to the origin, not the insertion; the midpoint of the muscle belly is not related to insertion; and the connective tissue covering (fascia) surrounds the muscle but is not an attachment site.
4. Conclude that the phrase 'The attachment site that tends to move toward the origin during muscle contraction' accurately describes the muscle's insertion.
5. Summarize that the insertion is the movable attachment point of a muscle, which is pulled toward the origin when the muscle contracts.