What Is My Rotator Cuff, and Why Does It Hurt?

Medically Reviewed by Jabeen Begum, MD on December 12, 2023
6 min read

Your rotator cuff is made up of muscles and tendons that keep the ball (head) of your upper arm bone (humerus) in your shoulder socket. It also helps you raise and rotate your arm. It’s a complicated process that your body makes look easy.

Rotator cuff muscles

Each one of the following muscles is part of the rotator cuff and plays an important role:

  • Supraspinatus. This holds your humerus in place, keeps your upper arm stable, and helps lift your arm.
  • Infraspinatus. This is the main muscle that lets you rotate and extend your shoulder.
  • Teres minor. This is the smallest rotator cuff muscle. Its main job is to help with rotation of your arm away from your body.
  • Subscapularis. This holds your upper arm bone to your shoulder blade and helps you rotate your arm, hold it straight out, and lower it.

These muscles are attached to your arm bone with tendons that form a covering (cuff) over the ball of the humerus.

Your rotator cuff helps you do things like get something off a high shelf and comb your hair. It’s especially important in sports like baseball, swimming, and tennis.

  • Rotator cuff tear. The tendons in your shoulder can become frayed, partially torn, or completely detached from the bone. It's often the result of wear and tear from daily use over time. You’re more likely to have this if you have a job where you need to move your arm a certain way over and over, like a painter or a carpenter, or you play sports like tennis and baseball. It also can happen suddenly if you fall on your arm or try to lift something heavy. 
  • Rotator cuff tendinopathy. Formerly called tendinitis, this is inflammation or irritation of a tendon that attaches to a bone. It causes pain in the area just outside the joint. Common types of tendinopathy include pitcher’s and swimmer’s shoulder.
  • Bursitis. The bursa (a small sac filled with fluid that protects your rotator cuff) can get irritated when you repeat the same motion over and over again, like throwing a baseball or lifting something over your head. Bursitis also can be caused by an infection.

A rotator cuff tear or other injury may cause:

  • Dull pain in your shoulder
  • Weakness in your arm
  • Trouble sleeping
  • Pain that appears when you touch your head or reach behind your back

Rotator cuff pain can limit the range of motion in your arm. You may feel grinding or crackling when you move your shoulder. Sometimes, you can have a rotator cuff injury and feel no pain at all.

To diagnose your shoulder pain, your doctor will move your arm around, press on or around your shoulder, and test the strength of muscles in your shoulder and arms.

You can't see a rotator cuff tear on an X-ray, but your doctor will be able to see other injuries to your shoulder such as arthritis or bone spurs.

You may have other tests, including:

Ultrasound, which shows soft tissue areas such as tendons and muscles and how your shoulder looks as it's moving. Your technician can scan your other shoulder to see how the two compare.

Magnetic resonance imaging (MRI), which can provide detailed images of the structure of your shoulder.

Most rotator cuff injuries get better over time without any kind of aggressive treatment. For tendinitis, bursitis, or a minor tear, your doctor may recommend: 

  • Rest, including avoiding repetitive motions or overhead sports (tennis, baseball, volleyball, swimming, and others)
  • A combination of ice and heat
  • Over-the-counter pain relievers like aspirin, ibuprofen, and naproxen
  • Physical therapy, which includes stretching and strengthening exercises to get you more mobile
  • If you still have pain and other symptoms after treating your rotator cuff injury at home, you may need different treatment.

Steroid injections

A shot of cortisone into the joint may help if your shoulder pain keeps you from sleeping or limits your daily activities. While they can provide quick pain relief, steroid shots can eventually weaken your tendons. 


About 80% to 85% of rotator cuff injuries are improved without surgery. Your doctor may recommend it if you're still in pain after trying other treatments. But it will depend on your age, your overall health, and what kinds of activities you do. There's no harm in trying nonsurgical options first. Doctors have found no difference in surgery outcomes if you have it right away or wait.

Surgery may be the first choice, though, if you tore a tendon completely during a fall or other accident. 

There are several types of surgeries for rotator cuff tears, depending on how serious your injury is. You may have the tendon reattached to the bone, or you may need your shoulder completely rebuilt.

Your rotator cuff can tear again after treatment or surgery, so it's important to prevent another injury. Here's what you can do: 

Protect your joint. Ask your doctor what movements and activities you should avoid to give your shoulder a chance to heal. Be cautious when you raise your arms over your head, and don't hold heavy items out away from your body. Pay attention to your posture, and if you do sports, check with a trainer to be sure you're using good form.

Strengthen. Building up the muscles in and around your shoulder will help keep your rotator cuff stable and lessen pain. Focus on the muscles in all parts of your shoulder, in your upper back, and in your arms. 

Get more flexible. After strengthening, gentle stretching will restore your shoulder's range of motion, reduce achiness, and lengthen your muscles. 

You'll get the best results from a shoulder conditioning program if you do your exercises two to three times a week. Before you start, talk with your doctor or physical therapist about the best kinds of exercise to do. 

How to strengthen the rotator cuff

  • Before starting your exercise program, take stock of the range of motion in your shoulder. This will help you rate your progress.
  • Begin your exercises slowly. Stop when you start to feel pain.
  • Warm up for 10 minutes before starting your exercises with a low-impact activity such as cycling on a stationary bike or walking.
  • Practice good posture in your shoulders: While sitting or standing, focus on pulling them down and holding them down.
  • Ice your shoulder for about 20 minutes a day.

The following are easy exercises to do at home with little or no equipment.

Pendulum. Place one hand on a table or countertop and lean forward. Your other arm should hang loosely at your side. Keep your back straight and bend your knees. Swing your arm gently back and forth, then from side to side, and finally in a circle. Repeat with your other arm for two sets of 10 repetitions. 

Shoulder stretch. Relax your shoulders and bring one arm across your chest. Bend your other arm and use it to pull the extended arm closer to your chest. Don't pull on your elbow. Hold the position for 30 seconds and relax for 30 seconds more. Do that four times, then repeat on the other side.

Sleeper stretch. Lie on your side on a firm surface with the injured shoulder down. Extend your affected arm straight forward and bend your elbow at a 90-degree angle so your hand points toward the ceiling. Using your other hand, grasp your arm above the wrist and press it down toward your hip. Stop when you feel a stretch in the back of your affected shoulder. Hold this position for 30 seconds and relax for 30 seconds more. Repeat four times, three times a day.

Elbow flex. Choose a weight that you can lift for three sets of eight repetitions. Stand, holding a weight in each hand with your elbows close to your sides. Slowly bend one arm, bringing the weight toward your shoulder and hold for 2 seconds. Return the weight slowly to your starting position. Repeat with the other arm. Increase the weight a pound at a time as the exercise gets easier, with a 10- to 15-pound maximum weight. 

Elbow pull. Attach the center of a resistance band to the knob of a closed door or another stable object. Facing the anchor point, take the ends of the band in each hand and hold your elbows bent at your sides. Step back until you feel tension. Steadily push both elbows back and then slowly return your arms to their starting position, squeezing your shoulder blades together as you pull. Do three sets of eight pulls.