The pectoralis minor muscle is a small strip like muscle located underneath the pectoralis major. It functions to protect the shoulder and aid in scapular movement and stabilization. This muscle almost always has trigger points in it due to chronic poor posture where the shoulders are rounded. Federal pain from these trigger points will cause pain to be felt in the chest and down the arm.
The scalenes muscles are located in the neck and help with neck movements and inspiration. The anterior scalene runs directly over the brachial plexus that gives nerve and blood supply to the arm. Poor neck and head posture as well as poor breathing mechanics can cause this muscle to become overloaded and develope trigger points. These points will refer pain into the shoulder, arm, and hand. As well as the shoulder blade. When tight, the anterior scalene muscle can put pressure on the brachial plexus causing numbness and tingling felt in the fingers and hand.
The levator scapulae muscle is a thin strap like muscle in your neck. It helps to shrug the shoulders and to side flex the neck. This muscle often becomes over worked when the head is tilted forward, or the shoulders are in an elevated position for prolonged periods of time. When strained trigger points develop. These points will refer pain into the neck and shoulder blade area. Trigger points in the levator scapulae are a main cause of a stiff neck.
The supraspinatus muscle makes up part of the rotator cuff. It is responsible for assisting in shoulder abduction as well lateral rotation and stabilizing the shoulder joint. This muscle is often overloaded in labourers and tradesman who have to do a lot of overhead work. Athletes who do a lot of throwing movements will also frequently have Tigger point in this muscle. These trigger points will cause pain to be felt into the shoulder and down the arm, as well as stiffness and weakness.