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.

ioSkeletal Myocytes provide a reliable, easy-to-use cellular model for muscle research ... efficiently and consistently generate functional skeletal myocytes at scale from iPSCs.” ...

A 3D polygonal model, guided by imaging scan data and muscle scarring, reconstructing the lower limb muscles of the Australopithecus afarensis fossil AL 288-1, known as ‘Lucy’.