How Does Frozen Shoulder Affect Muscles?

There are lots complex joints in the body, and one of them is your shoulder. Frozen shoulder (adhesive capsulitis) is a painful condition that can lead to pain and stiffness. The effect of the disease should not be systemic. However, it can affect the muscles surrounding the affected shoulder joint, too – how?

The joint of shoulder is formed where the shoulder blade (the scapula) meets to the upper arm bone (called humerus), like socket and ball.

Both scapula and humerus are important to support the shoulder function. However, there are also other important bones (see the following picture, credit to Web MD):

The coracoid process, it is a hook-like assertion from the scapula.  Acromion, it is a bony assertion off the scapula. And the collarbone (clavicle), a bone that meets to the acromion.

Other important structures include:

1. A small sac of fluid called bursa. It has crucial function to protect and cushion the tendons of the rotator cuff.
2. Labrum (a cuff of cartilage) forms a cup for the ball-circular-like head of the humerus to fit into.
3. And rotator cuff! It hoses lots of muscles and tendons to give the shoulder joint a wide range of motion.

Most of these structures are encased in a capsule of connective tissue.

And adhesive capsulitis or frozen shoulder occurs when this capsule become tight and thickened, restricting (freezing) the movement of the shoulder joint.

Frozen shoulder is not the only one. There are numerous different health conditions that can affect shoulder, these include:

Rotator cuff tear

Actually, rotator cuff itself is a group of 4 tendons and muscles surrounding the shoulder joint (specifically at the top of the humerus). Together, these tendons and muscles form a ‘cuff’ to support the range of motion of the shoulder, as noted before.

Rotator cuff tear can be a nightmare for the function of the shoulder. Even in athletes, it can end their career.

Both of your shoulder joints play a key role in your daily routines. But in fact, they are also somewhat weak. Too many fastballs (too much stress) can lead to tears & swelling in the rotator cuff (especially in the tendons of rotator cuff).

Arthritis

It is a common condition that affects joints. It has several types.

Some that are often reported can affect shoulder joints are osteoarthritis (the most common arthritis form), rheumatoid arthritis (a systemic, inflammatory arthritis), and gouty arthritis (a condition related to uncontrolled high uric acid that accumulate in the joint).

Bursitis

It is a bursa inflammation. Bursa itself is the small sac of fluid that rests over the rotator cuff tendons. Bursitis can lead to pain in the upper arm.

Other conditions

1. Tendonitis, the inflammation that occurs in a shoulder’s tendon (especially one of tendons in the rotator cuff).
2. Dislocation, a condition of when one /some bones in the shoulder slip out of position.
3. And shoulder impingement. The impingement can occur when acromion excessively presses on the rotator cuff. The problem will cause pain if the rotator cuff is inflamed or injured.

Interestingly, many of these shoulder conditions have similar signs and symptoms. This makes the way to diagnose the problem is not always easy!

This condition can be painful enough to affect your daily routines. And when the pain starts to ease, stiffness gradually increases – causing the same problem to your shoulder, ‘limiting the range of motion’.

Although it is not a systemic condition, sometimes it causes pain beyond the shoulder. Some patients say that they experience pain in the bicep, arm, neck, or even back (see more in here)!

Frozen shoulder can affect the muscles, too. In fact, this problem is a long-term condition.

When the affected shoulder become painful and stiff, over time the muscles surrounding the shoulder may waste a bit because they are not actively in use.