The latissimus dorsi muscle can contribute to pain in the shoulder, upper back, and arm going down into the hand. The muscle can also cause pain in the side of the ribcage and lower abdomen. It is the muscle that most often causes the ‘side stitch’.
The deltoid is the muscle that covers the tip of the shoulder. It contributes to pain in the shoulder and upper arm. One indication of problems with the deltoid muscle is pain is most intense during activity and subsides when resting the shoulder and arm.
The teres major is a shoulder muscle. It can contribute to pain in the shoulder, upper arm, and forearm. An indication of teres major muscle involvement is pain is felt in the shoulder and upper arm skipping the elbow and reoccurring in the back of the forearm.
The supraspinatus muscle is one of the four rotator cuff muscles. It contributes to pain in the shoulder, outside of the arm and elbow. Pain is a deep aching that often persists during rest.
