Which statement about muscle action is described in the material?

Which statement about muscle action is described in the material?

• A. Muscle fibers pull but can't push
• B. Muscles are attached to bones by ligaments
• C. Muscles push to move
• D. Muscles are not involved in movement

Answer: (C)

Muscle action relies on contraction to generate a pulling force on the bones, not pushing. When a muscle contracts, it shortens and pulls on the bone to which it is attached, creating movement at the joint. Movement usually happens with opposing muscles working in pairs: as one muscle pulls to flex a joint, its partner lengthens or relaxes to allow that motion, and the roles reverse to straighten it again. For example, bending the elbow involves the biceps pulling the forearm up while the opposing muscle relaxes to permit the movement. Ligaments connect bones to each other, not muscles, and muscles are indeed involved in movement. The idea that muscles push to move isn’t how it works because pulling is the mechanism by which muscles generate force.

Muscle action relies on contraction to generate a pulling force on the bones, not pushing. When a muscle contracts, it shortens and pulls on the bone to which it is attached, creating movement at the joint. Movement usually happens with opposing muscles working in pairs: as one muscle pulls to flex a joint, its partner lengthens or relaxes to allow that motion, and the roles reverse to straighten it again. For example, bending the elbow involves the biceps pulling the forearm up while the opposing muscle relaxes to permit the movement. Ligaments connect bones to each other, not muscles, and muscles are indeed involved in movement. The idea that muscles push to move isn’t how it works because pulling is the mechanism by which muscles generate force.