Which muscles are related shoulder pain?
Muscles surrounding the shoulder joint
Trapezius muscle
Trapezius muscle attaches to the base of the skull and extends down until mid back and laterally it inserts to the shoulder blades. It is involved in the shoulder blades movement
Pain caused by middle and lower part of the trapezius can present burning pain or aching on the top of the shoulder. Also pain caused by the lower part of the muscle can present upper shoulder pain; pain at the back of the shoulder blade which could radiate to the inside of the arm to the ring and little fingers.
Latissimus dorsi
Latissimus dorsi is the largest flat muscle in the back.
It originates from the inferior thoracic and lumbar vertebrae, sacrum, iliac crest, and the four most inferior ribs, runs laterally up through the back, inferior part of shoulder blades and inserts to the upper front of the humerus. This muscle plays a role in shoulder joint movement such as adducting the arms, extending the shoulders and rotating shoulder joints medially. Tight latissimus dorsi and the trigger points in the muscles could be one of the causes of shoulder pain, forearm pain, pain between shoulder blades, shoulder blades and pain in front of shoulder.
There are seven muscles that connect the upper arm to the shoulder blades.
Rotator cuff
Rotator cuff is a group of four muscles including supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle. They connect the scapula to the head to the humerus (arm) , stabilize shoulder joint and contribute to shoulder joint movement including abduction, internal rotation, and external rotation of the shoulder. Rotator cuff problem such as injury or overuse of these muscles can cause shoulder pain which is characterised as pain around the shoulder and reduced shoulder joint movement.
Teres major muscle
Teres major muscle also connects shoulder blades to the upper arms starting from lower angle of the shoulder blade and ending at the upper arm in the front of the shoulder. The teres major muscle is involved in adducting the arm, stabilising the humeral head, extending the shoulder and rotating it inwardly. The teres major trigger points cause pain at the back of the shoulder which can radiate to the front and side of the shoulder and down the backside of the arm.
Deltoid muscles
The deltoid muscle forms the rounded contour of the shoulder and is the big muscle on the shoulder. It has three parts; the front, middle and back. The front part is involved in flexing the shoulder and internally rotating the arm. The middle part is involved in shoulder abduction. The back part is involved in extending the shoulder and externally rotating the arm.
Coracobrachialis muscle
This is the smallest muscle that connects upper arm to the shoulder blade. It plays a part in adduction, flexion, and inward rotation of the arm. It also helps stabilise humeral head within the joint.
Muscles connected chest and shoulder
Pectoralis major and minor muscles
The pectoralis major muscle and the pectoralis minor muscle are the muscles located at the chest They are overlapped.
The pectoralis muscle originated from inner half of the clavicular bone, sternum as well as the cartilage of the sixth or seventh rib and the aponeurosis of the abdominal muscle. The muscle goes laterally and inserts to the upper arm. It adducts the arm and rotates the shoulder inwardly, pull down the shoulder joint and elevated the arm to the front. Pectoralis minor originates from 3-5 ribs and it runs upward and laterally and inserts to the surface of the coracoids process of the scapula. It pulls the shoulder blade downward, forward and inward towards the ribs, stabilizes the shoulder. The trigger point of the muscle contributes to the pain in front of the shoulder that could radiate to the chest, upper arms and all the way down to the inner side of the forearm.
Trapezius muscle
Trapezius muscle attaches to the base of the skull and extends down until mid back and laterally it inserts to the shoulder blades. It is involved in the shoulder blades movement
Pain caused by middle and lower part of the trapezius can present burning pain or aching on the top of the shoulder. Also pain caused by the lower part of the muscle can present upper shoulder pain; pain at the back of the shoulder blade which could radiate to the inside of the arm to the ring and little fingers.
Latissimus dorsi
Latissimus dorsi is the largest flat muscle in the back.
It originates from the inferior thoracic and lumbar vertebrae, sacrum, iliac crest, and the four most inferior ribs, runs laterally up through the back, inferior part of shoulder blades and inserts to the upper front of the humerus. This muscle plays a role in shoulder joint movement such as adducting the arms, extending the shoulders and rotating shoulder joints medially. Tight latissimus dorsi and the trigger points in the muscles could be one of the causes of shoulder pain, forearm pain, pain between shoulder blades, shoulder blades and pain in front of shoulder.
There are seven muscles that connect the upper arm to the shoulder blades.
Rotator cuff
Rotator cuff is a group of four muscles including supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle. They connect the scapula to the head to the humerus (arm) , stabilize shoulder joint and contribute to shoulder joint movement including abduction, internal rotation, and external rotation of the shoulder. Rotator cuff problem such as injury or overuse of these muscles can cause shoulder pain which is characterised as pain around the shoulder and reduced shoulder joint movement.
Teres major muscle
Teres major muscle also connects shoulder blades to the upper arms starting from lower angle of the shoulder blade and ending at the upper arm in the front of the shoulder. The teres major muscle is involved in adducting the arm, stabilising the humeral head, extending the shoulder and rotating it inwardly. The teres major trigger points cause pain at the back of the shoulder which can radiate to the front and side of the shoulder and down the backside of the arm.
Deltoid muscles
The deltoid muscle forms the rounded contour of the shoulder and is the big muscle on the shoulder. It has three parts; the front, middle and back. The front part is involved in flexing the shoulder and internally rotating the arm. The middle part is involved in shoulder abduction. The back part is involved in extending the shoulder and externally rotating the arm.
Coracobrachialis muscle
This is the smallest muscle that connects upper arm to the shoulder blade. It plays a part in adduction, flexion, and inward rotation of the arm. It also helps stabilise humeral head within the joint.
Muscles connected chest and shoulder
Pectoralis major and minor muscles
The pectoralis major muscle and the pectoralis minor muscle are the muscles located at the chest They are overlapped.
The pectoralis muscle originated from inner half of the clavicular bone, sternum as well as the cartilage of the sixth or seventh rib and the aponeurosis of the abdominal muscle. The muscle goes laterally and inserts to the upper arm. It adducts the arm and rotates the shoulder inwardly, pull down the shoulder joint and elevated the arm to the front. Pectoralis minor originates from 3-5 ribs and it runs upward and laterally and inserts to the surface of the coracoids process of the scapula. It pulls the shoulder blade downward, forward and inward towards the ribs, stabilizes the shoulder. The trigger point of the muscle contributes to the pain in front of the shoulder that could radiate to the chest, upper arms and all the way down to the inner side of the forearm.
