Muscle movement requires the cooperation of both the nervous system and the musculoskeletal system.

Movement occurs when groups of muscle cells contract.

Electrochemical impulses from the nervous system stimulate fibers called sarcomeres, causing them to shorten. Contraction continues until the impulses cease and the muscle once again relaxes.

As muscles contract, the bones to which they are attached move.

Joints?lubricating structures between bones?make movement smoother.

Thanks to the teamwork of muscles, bones and joints, locomotion is possible.