The muscular system consists of about 600 skeletal muscles—striated muscles that are usually attached to bone. (The term does not include smooth or cardiac muscle.) The form and function of the muscular system occupy a place of central importance in several fields of health care and fitness. Physical and occupational therapists must be well acquainted with the muscular system to design and carry out rehabilitation programs. Nurses and other health-care providers often move patients who are physically incapacitated, and to do this safely and effectively requires an understanding of joints and muscles. Even to give intramuscular injections safely requires a knowledge of the muscles and the nerves and blood vessels associated with them. Coaching, movement science, sports medicine, and dance benefit from a knowledge of skeletomuscular anatomy and mechanics.

Myology, the study of muscles, is closely related to what we have covered in the preceding chapters. It relates muscle attachments to the bone structures described in chapter 9 and muscle function to the joint movements described in chapter 10. In this chapter, we consider the gross anatomy of the muscular system and how it relates to joint movements. In the following chapter, we examine the mechanisms of muscle contraction at the cellular and molecular levels.