What are the relationship between the muscular and the skeletal system in the way they function?

The biggest relationship between them is between skeletal muscles and bones. Skeletal muscle acts upon bones to move. An example of this are the semitendinosus, the semimembranosus and the biceps femoris muscles, collectively called the hamstrings, which act upon the coxa (hip) and patella (knee) to move the upper part of the legs.