What are the supporting, protective and motor functions of the skeleton and muscles?

The skeleton is the hardest part of the body and serves as a support for it. The muscles support the internal organs as well as the skeleton in the required position.
The skeleton and muscles protect the internal organs from injury. So, the bones of the chest protect the heart and lungs, the abdominal muscles protect the abdominal organs.
The muscles of the skeleton tend to contract and relax voluntarily. Contraction of some muscles and relaxation of others allows you to change body position and provides motor function.