We move thanks to coordination among many skeletal muscle fibers, all twitching and pulling in sync. While some muscles align ...

Muscles can only contract and relax, so they always work in pairs called antagonistic muscles. Skeletal muscle is joined to bones. Its cells contract to make bones move and joints bend.

Within the sarcomere, myosin slides along actin to contract the muscle fiber in a process that requires ATP. Scientists have also identified many of the molecules involved in regulating muscle ...