The role of Pectoralis Major in movement of the arm and shoulder
Humans are vertebrates meaning the structure of human is based on the skeletal system which consists of numerous bones, cartilage, tendons, ligaments and muscle. The bones primarily support mechanical movement, protect the organs and provide stability. The muscles are specialized cells which keep the bones intact and both bones and muscle work together to provide fluid and easy physical movement. The muscles work due to contraction and almost all the movement a person experiences is due to muscle contraction. The proper muscle function enables a person to maintain a proper posture and keeps the joints stable. Pectoral muscles are muscles that are present on the front of human chest and connect the chest bones with the shoulder and arm of the human. There are two types of pectoral muscles, ‘pectoralis major’ and ‘pectoralis minor’. Pectoralis major is a thick, fan shaped muscle while Pectoralis minor is thin and triangular shaped muscle. The pectoral muscles are used in movement of arm and also play important part in breathing.
Significance of Pectoralis Major:
Pectoralis major is one of the two pectoral muscles, it is a thick, and fan shaped muscle that covers the upper chest region connecting the sternum with first six bones of the ribcage. Pectoralis major muscle lies beneath the breastbone and below it lies the Pectoralis minor. The pectoral muscles are mostly used to control the movement of arm which is result of contractions of Pectoralis major which pulls the humerus to allow rotational, vertical and lateral motion. The pectoral muscles also serve a purpose when breathing especially people who exercise as the body requires more oxygen. The pectoral muscles pull the ribcage closer, making more room for lungs to expand and inhale more air. The movements that Pectoralis major muscle makes possible are
- Moving the arm in towards and across the body
- Lowering the arm towards the body when arm is extended to one particular side of the body.
The pain and symptoms caused by Pectoralis major muscle:
When a person feels pain in the shoulder, chest or arm and even in the finger, the pain could be linked due to some problem or strain in the Pectoralis major muscle. The dysfunction of Pectoralis major can also cause pain in the upper back region and in the shoulder blades. The symptoms of pain can include
- Pain and discomfort in the insides of the arm and in the front of the shoulder
- When a person feels some sort of chest pain and aching in the upper back around the shoulder blades.
There are certain activities that can cause injuries and pain in the Pectoralis major muscle. Some of the common reasons are
- Lifting heavy objects which is common with people who exercise and lift weights.
- Continuously working on the computer desk with your arms positioned upwards or resting on the desk
- When carrying a heavy bag on one shoulder without alternating the weight between the two shoulders
- When keeping your body in wrong posture such as slouching and bending your back warkwardly
The people who experience pain caused by Pectoralis major muscle can use hot cold packs or certain pain relieving creams such as therapy gel. The therapy gel is effective and can be easily applied to the affected area and the gel quickly helps to relieve the soreness of the muscle pain.