Functions of the Breastbone Muscle

The breastbone muscle is really a set of two large muscles that cover the breast bone. These muscles have a variety of uses for everyday movements and help protect the chest cavity and heart from injury.

The breast bone is also known as the sternum. The sternum is a t-shaped bone located in the front of the chest and where the ribs connect to one another by cartilage. It serves to protect the chest cavity from injury. The muscles that cover the breast bone area are known as the Pectoralis major muscles. These muscles make up the majority of the front of the chest, starting below the collar bone and over the sternum. They attach to the humerus or upper arm near the joint of the shoulder and to the breast bone. The muscle fibers of the pectoralis are fan shaped to allow for a variety of movements. These muscles are large and well supplied with blood from the pectoral branch of the thoracoacromial trunk. The muscles are easy to see in men, but usually sit underneath of the breasts in women. The Pectoralis minor is a smaller and thinner muscle found under the Pectoralis major muscles. The pectoralis muscles receive nerve stimulation from the brain through the medial and lateral pectoral nerves. This makes these muscles able to be voluntarily moved by the person. These muscles are vitally important in keeping the arm attached to the body.

The pectoralis muscles have several responsibilities involving moving the shoulder joint in order to perform a wide array of everyday actions. The pectoralis major allows the humerus to move in variety of ways including rotating it medially for activities like arm wrestling, moving the humerus up and down and flexion of the humerus. The flexion of the humerus by the pectoralis muscle allows for the motion used to throw a ball. The pectoralis major muscles are also useful for inhaling a large amount of breath. The pectoralis minor muscle is responsible for moving the shoulder forward, as seen during a shrug.

Large and toned pectoralis muscles are often a sign associated with overall strength and power. This makes these sets of muscle important for bodybuilders and other athletes. Many athletes will attempt to strengthen their pectoralis muscles in order to increase the movement and strength of their humerus and arm.  Sometimes a strain or sprain of the breast bone muscle can lead to pain and swelling. Symptoms of this type of muscle problem usually involve aching, swelling and bruising. The muscles that lay within the ribs, also called the intercostals muscles, may also experience this type of pain. It is also possible to tear the muscles located on the chest. This type of injury takes a long time to heal and can be rather painful. Other types of injury that can affect this muscle group can result from traumatic injury. Blunt force trauma can cause severe bruising and pain in the muscle and the muscle can be pierced by objects as well. These types of injuries are often the result of car accidents or sports related accidents. Any injury to the chest area should be considered severe and should be checked out by a doctor. Chronic or serious respiratory problems can also injure the muscles located around the chest. Examples of these types of problems are asthma and emphysema.

While these chest muscles are often overlooked, they provide a variety of services in the form of movement and protection. The breast bone muscle not only works to move the shoulder and arm, but often they are used by both men and women to attract the opposite sex, as a strong set of pectoralis is considered to be very attractive.