The rotator cuff is a set of muscles that helps the arm and shoulder move. Injuries to the rotator cuff are fairly common, but many effective treatments are available.

The rotator cuff comprises four muscles: the supraspinatus, the infraspinatus, the teres minor, and the subscapularis.

These muscles work together to control arm movement and shoulder rotation. They also help keep the head of the upper arm bone, known as the humerus, in the socket of the shoulder blade, or scapula. This socket is called the glenoid.

Rotator cuff injuries are relatively common, especially in older adults, athletes, and those with physically demanding jobs. A medical professional can diagnose a rotator cuff injury and recommend the proper course of treatment.

In this article, we discuss the anatomy and function of the rotator cuff and common injuries that affect this muscle group.

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The rotator cuff is a group of four muscles and tendons that attach the humerus to the scapula. These muscles and tendons surround the shoulder joint like a cuff and provide stability.

In addition to their collective function, these muscles also have their own individual actions. For example, the supraspinatus abducts the arm, moving it away from the body, and assists with moving the deltoid muscle in the shoulder. The infraspinatus and teres minor both aid the lateral rotation of the arm, while the subscapularis medially rotates the arm.

Alongside the groups of muscles that comprise the rotator cuff, other components help with movement and function.

Several nerves connect these muscles and send important signals throughout the rotator cuff. These include the subscapular nerve, the suprascapular nerve, and the axillary nerve. The rotator cuff also contains bursae, which are fluid-filled sacs that separate tissues. These bursae act as cushions that protect different tissues by reducing friction.

Some common rotator cuff injuries include:


A rotator cuff tear involves an injury to one of the cuff tendons. This tear can injure one or multiple tendons, but it most commonly affects the supraspinatus tendon.

A tear can be either partial or full-thickness. A partial tear, also known as an incomplete tear, damages the tendon but does not completely sever it. A full-thickness, or complete tear, totally severs the tendon from the bone and may leave a hole in the tendon.

The main causes of a rotator cuff tear are injury and degeneration. An acute tear happens when trauma or an accident results in injury and a torn tendon. However, most tears are degenerative, which means that they happen slowly over time. A degenerative tear could develop as a result of ongoing stress to the tendon, lessened blood supply during aging, or bone spurs.

Medical professionals may use imaging techniques such as X-ray, ultrasound, and MRI to help diagnose a full or partial tendon tear.


Rotator cuff tendinitis is the term for inflammation of the rotator cuff tendons. This condition can affect people of any age with varying degrees of activity level.

Tendonitis typically occurs due to irritation or damage to the tendons following sporting or repetitive overhead movements. Some people may also experience a shoulder impingement, also known as swimmer’s shoulder, in which a tendon or bursa rubs against the shoulder blade, causing pain. This type of injury is common among people who play sports such as baseball and tennis or have occupations such as construction and painting.

After asking about the person’s specific symptoms, a doctor may perform a physical exam and suggest imaging tests to help confirm the diagnosis.


Bursitis refers to the inflammation of a bursa. These lubricating sacs allow the rotator cuff tendons to glide freely when a person moves their arm. However, too much friction in the shoulder from repetitive movements or trauma may cause irritation and result in bursitis.

Similar to other rotator cuff injuries, a doctor will typically perform a physical exam and use imaging tests to help diagnose bursitis of the shoulder.

The symptoms of rotator cuff injury vary depending on the individual and the injury they have sustained. Some common symptoms of injury may include:

  • pain or swelling in the shoulder
  • difficulty moving the arm
  • a clicking or popping sound when moving the arm
  • weakness in the shoulder

Treatment options may also vary depending on the type and severity of the rotator cuff injury. As part of treatment and recovery, a doctor may recommend:

  • taking over-the-counter nonsteroidal anti-inflammatory drugs or pain medications to minimize swelling and discomfort
  • applying cloth-wrapped ice packs to the affected area
  • resting and avoiding activities that may irritate the shoulder
  • sleeping on the unaffected side or on the back
  • taking warm baths or showers to help relax the muscles

In some cases, when a person can comfortably use their shoulder, a doctor may suggest using rehabilitation exercises to aid healing. These exercises and stretches may also help prevent future injuries. A doctor may also refer a person to a physical therapist or specialist for other treatment options.

In more severe cases, for which nonsurgical options will likely prove ineffective, a doctor may suggest surgery.

Anyone experiencing chronic shoulder pain should consider contacting a doctor or orthopedic surgeon. These professionals can evaluate the shoulder, determine the cause of pain, and suggest treatment options to relieve symptoms and aid recovery.

The rotator cuff is a group of four muscles that control arm movement and shoulder rotation. As the shoulder joint is very mobile, and people use it frequently for both sport and work, injuries to the rotator cuff are fairly common.

Anyone who experiences severe or persistent pain in their shoulder should consult a doctor to get a diagnosis. The treatment typically involves resting, avoiding strenuous activities, and performing gentle stretches.