The subscapularis, located in the front of the shoulder, is one of the four muscles that make up the rotator cuff. It is the most powerful of all the rotator cuff muscles. Its function is to help the shoulder joint move and create powerful motions such as internal rotation, which occurs when the arm is pulled toward the body as with a tennis stroke or with swimming.
The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. From the subscapular fossa, the subscapularis muscle extends out to the side of the body and inserts onto the humerus, which is the long bone of the upper arm. Specifically, this muscle inserts onto the lesser tubercle of the humerus. The lesser tubercle (also known as the lesser tuberosity) is a round prominence located at the front, top of the humerus. The lesser tubercle is located right next to the larger greater tubercle.
Subscapularis tendon injuries are relatively rare. Most injuries of the rotator cuff involve either the supraspinatus tendon on top of the shoulder or the infraspinatus tendon in back of the shoulder. Subscapularis tendon injuries usually occur as the result of a traumatic event, such as a fall, and usually, affect individuals who are younger than those who typically present with a supraspinatus tendon tear.
Suprascapular Nerve, C5 & C6.
Subscapularis is innervated by both the upper and lower subscapular nerves which come from the posterior cord of the brachial plexus. The upper subscapular nerve supplies the upper part of subscapularis, while the lower subscapular nerve branches into two, with one branch supplying the lower part of subscapularis.
What Does the Subscapularis Do?
There are a couple different actions of the subscapularis muscle. These actions include:
- Medial rotation of the humerus: the inward turning or twisting of the upper arm, such as when you rotate your upper arm inward when you slam a door closed
- Abduction of the humerus: moving the upper arm towards the body, such as the downward motion of your arms when you are flapping your arms
- Stabilization of the shoulder joint: keeping the head of the humerus in its correct location against the scapula when the arm is moving throughout the shoulder joint
How Do We Define Subscapularis Tendinitis?
The Subscapularis muscle is an extremely powerful muscle of the rotator cuff which facilitates inward movement of the arm. The Subscapularis Muscle is usually injured in individuals who participate in sporting activities which require frequent throwing like baseball etc. It is a very difficult medical condition to treat
This is a painful medical condition of the shoulder in which there is inflammation of the tendons of the subscapularis muscle resulting in severe pain in the shoulders and difficulty with mobility of the shoulders.
Causes of Subscapularis Tendinitis
Subscapularis Tendinitis usually occurs due to a direct trauma to the arm like that in a fall on the shoulders or arm or as a result of a sporting injury. A rupture of the tendon may also occur after a surgical procedure such as a shoulder replacement surgery in which the subscapularis tendon is removed and repaired.
Diagnosis of Subscapularis Tendinitis
The confirm the diagnosis of Subscapularis Tendinitis, the treating physician will evaluate the shoulder thoroughly for any sort of abnormality in the range of motion by asking the individual to elevate the elbows and internally rotate the forearms. After this, the physician will look for any weakness in the shoulder muscles for a confirmatory diagnosis. Radiological tests like x-ray, MRI or CT scan may also be done to confirm the diagnosis.
Symptoms Of Subscapularis Tendinitis
Some of the symptoms of Subscapularis Tendinitis are pain with any type of movement of the shoulder, especially overhead motions. Pain may also be induced with inward motion of the arms. In few cases pain is observed during sleep and early morning. Subscapularis tendonitis symptoms include pain when moving the shoulder especially when the arm is raised above the shoulders.
Pain is often caused by hyperextension of shoulder joint during sleep resulting in hyperextension of rotator cuff and subscapularis tendon.
Referred (prigected) pain could be felt in lower aspect of armpit, when lower portion subscupularis is injured. The pain could even be felt in the breast tissue by female patients. Subscapularis can harbour up to three trigger points, with the two most common occurring near the outside edge of the muscle. Luckily, the trigger point on the inside edge of the muscle s much less common, because it is nearly impossible to contact by palpation and release manually.
Referred pain from trigger points in the subscapularis muscle concentrates in the posterior shoulder region, with spillover into shoulder blade region and down the back of the upper arm. A unique “band” of referred pain around the wrist may occur as well. Typically the client is aware of this wrist pain, but does not think it is related to their shoulder pain.
It is often injured by throwers. Tenderness and pain will be felt when pressing in on the tendon insertion on the inside of the upper arm.
An overworked subscapularis muscle may make you feel like you are not able to lift your arm. It may be even responsible for your frozen shoulder.
The subscapular tendon inflammation is mild to moderate and responds to treatment
Rest until it is not painful. Apply ice initially to help reduce pain and inflammation.
Feel it contracting, then release the tension and start to massage it. Make sure you only massage the muscle and not your nerves. Otherwise, you are likely to end up with some pain for quite a few days because you stressed the nerves in your armpit instead of the muscle.
For massaging the subscapularis muscle use thumb technique.
- Performing isometric exercises that target the subscapularis involves contracting the muscle for five to 10 seconds at a time without moving your shoulder joint considerably.
- Start position: Stand with your knees slightly bent and feet in a split stance. Hold the elastic tubing at shoulder height with an elbow out to your side and slightly bent.
Action: Against the resistance, bring your hand across and in front of you until you touch the front of your opposite hip. Return to the starting position.
Key points: You should rotate gradually through your shoulder as you bring your hand across your body.
3. Perform the side-lying internal rotation exercise with a dumbbell while lying on a flat bench or table. Start with the dumbbell in your left hand and lie on your left side with your elbow tucked into the left side of your abdomen and your forearm pointed forward, extended over the edge of the bench. Lift the weight until your forearm touches your belly, then lower it slowly and repeat. Complete at least eight repetitions, then turn over and switch arms.
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