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 levator scapulae connect the shoulder blade to the vertebra of the neck. The muscle contributes to pain in the shoulder, neck, and the base of the skull. The muscle causes a stiff neck. It can contribute to headaches at the base of the skull and up into the back of the head.
The subclavius muscle is found just under the collarbone. It contributes to pain in the area around the clavicle (collarbone), shoulder, upper arm, forearm, thumb and fingers. It can also contribute to tingling and numbness in the arm and hand.
The coracobrachialis muscle connects the shoulder to the upper arm. It can contribute to pain in the shoulder, back of the arm, and occasionally the middle finger. Pain is often felt when attempting to put your hand behind your back and or raising your arm over your head.
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 infraspinatus muscle lines the back of the shoulder blade. It is one of the muscles that can contribute to frozen shoulder. The muscle can cause pain in the shoulder, neck, pain down the outside of the arm which descends down into the thumb and hand. Shoulder mobility can be greatly reduced.
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.
The subscapularis muscle is found on the inside of the shoulder blade. It can cause severe pain in the shoulder blade area that can also run down the back of the arm. Pain is also often felt in the wrist, but not the forearm.
The trapezius muscle is located in the upper back. It can contribute to headaches and pain in the eye, jaw, neck, top of the shoulder and upper back. It can also contribute to tingling in the arm.
The teres minor connects the shoulder blade to the upper arm and is one of the rotator cuff muscles.