, what does your skeleton do? The bones in your skeleton act as anchors for all your muscles. Muscles work to pull your bones in different directions. Take the muscles in your arm. Like most muscles they work in pairs - as one expands (gets bigger) the other contracts (gets smaller) allowing you to move your arm around the elbow joint. Your skeleton also provides you with support and protection. Imagine the damage you could do to your brain if you didn't have a skull to protect it!