The shoulder is the portion of the body that joins the arm to the chest and back. As the most mobile joint in the body, it has the largest range of movement and helps control the arm. Our shoulders allow us to reach overhead, in front of and behind us.

Shoulder anatomy 

To understand shoulder injuries, you first need to understand the different parts of the shoulder and how they work together. The upper arm bone (humerus) rests in a cup-like bone called the glenoid. The shoulder blade (scapula) sits behind the glenoid and the collarbone comes over the top. Basically, the point where all these bones come together, along with the surrounding muscles, is the shoulder.

There are several components that help stabilize the shoulder, including:

Rotator cuff

A group of muscles and tendons, known as the rotator cuff, surround the shoulder. These muscles help stabilize your shoulder during activities, such as throwing.


The labrum is a thin rim of cartilage that helps secure the ball at the top of the arm bone (humeral head) in the glenoid socket. This fence-like tissue provides depth to the glenoid, helping to keep the humeral head in the center of the socket.

Shoulder capsule

The shoulder capsule is a thin sheet of connective tissue that surrounds the humeral head and attaches to the glenoid rim. There are four major ligaments in the capsule that work to keep the humeral head centered on the glenoid during overhead motions.

Dynamic stabilizers

Dynamic stabilizers are a group of muscles that include the rotator cuff, biceps and scapular stabilizers. These muscles move the shoulder through elevation and rotation and help the labrum and capsule stabilize the humeral ball in the center of the socket. They also keep the shoulder blade moving smoothly during overhead motions. In other words, dynamic stabilizers allow you to move your arm in an overhead motion quickly, like to throw a ball, and keep you from dislocating your shoulder during the process.

Acute Shoulder Injuries

Broken shoulder
A “broken shoulder,” typically refers to a broken bone in the upper portion of the arm (humerus). These fractures tend to heal quickly and without surgery. A specialized sling is worn to keep the arm in a steady position. Rarely, surgery may be needed to repair a humeral fracture.

AC joint injuries
The AC joint has two key groups of ligaments that help support it. The AC ligament runs side-to-side and a pair of Coracoclavicular (CC) ligaments help stabilize the joint from top to bottom. AC joint injuries are usually caused by direct trauma to the shoulder.

Treatment depends on the severity of the injury. Your child’s doctor will usually take an X-ray to see if the collarbone is displaced. Most of the time AC joint injuries do not require surgery, except in severe cases.

Proximal humeral physeal fractures
Injuries to the growth plate of the humerus (upper arm bone) can happen from overuse or after a traumatic event. But since children’s bones grow quickly, children can usually fully recover without surgery. Breaks can be located through, above, below or both above and below the growth plate. If your child has a severe fracture where the bones are now far apart, your doctor may recommend surgery using pins, plates and screws, or a rod that goes into the arm bone to stabilize the break until it heals.

Humeral shaft fractures
Breaks in the middle of the upper arm bone are often due to trauma, such as car accidents or falls. And with this type of fracture, there is also a risk of injury to one of the nerves in the arm. Your doctor will perform a thorough physical exam during the initial evaluation and throughout the course of your child’s treatment to determine whether this is present. Often these breaks don’t need surgery and can be treated with immobilization. Initially, the injured arm is placed into a splint and a sling. Typically, one to two weeks later, once the initial swelling has gone down, your child can be transitioned into a Sarmiento brace, which secures the arm and compresses the soft tissues.

Shoulder Dislocation

Dislocated shoulders happen when your child’s arm is pulled up or backward and forced out of the socket. They may also occur when falling on the shoulder or onto an outstretched hand.

The upper arm bone (humerus) fits into the shoulder socket (glenoid). The joint is held in place by soft tissue, which includes cartilage attached to the shoulder socket (labral cartilage), connective tissue and rotator cuff muscles. In a dislocated shoulder injury, these tissues are stretched or torn.

The main symptom of this injury is severe pain that gets worse with movement, but there are others including an appearance of a lump sitting outside the shoulder joint and numbness in the upper arm caused by stretching of nerves.


Treatment for a dislocated shoulder involves a doctor putting the arm back in the joint. Your child’s pain should then mostly subside, but you can continue to apply ice as needed for pain and swelling. The injured shoulder will be placed in a sling to prevent movement and promote healing during a period of rest. After that, sports physical therapy exercises will be prescribed to stabilize the shoulder and hopefully prevent re-injury. If the shoulder continues to dislocate, surgery may be necessary.

Shoulder Impingement and Rotator Cuff Tendonitis

Shoulder impingement

Shoulder impingement, sometimes called subacromial impingement, is the most common cause of shoulder pain and is usually most noticeable during overhead activities, such as throwing. Your doctor will examine your child’s arm and shoulder and likely order X-rays to pinpoint what’s causing the pain. If your child’s shoulder is not showing improvement within four to six months, your doctor may recommend surgery.


A doctor trained to treat shoulder problems, like an orthopedic surgeon, will test your range of motion, strength and stability during a physical exam.

  • An X-ray may be used to see if there are other bone problems, such as fractures or growth plate injuries.
  • An MRI can pinpoint injuries to the shoulder joint or tears in the cartilage.


  • Use modified workouts and rest the shoulder until the pain is gone
  • Ice and anti-inflammatory medicine to ease the pain
  • Sports physical therapy for six to eight weeks to improve strength, range of motion and stability


For all sports, stop playing or practice if you have shoulder pain. Here are some tips to prevent shoulder impingement for specific sports:

Baseball or softball

  • Change positions for easier throws
  • Avoid overuse
  • Have an expert assess throwing motion
  • Hit only if it doesn't make the pain worse


  • Reduce overhead motion because it can cause more stress on the shoulder than ground strokes.
  • Reduce serves and overhead shots.


  • Train in slower lane to reduce pain
  • Stop land workouts or exercises if they overwork painful shoulder
  • Don’t use aids like kick boards if they cause pain
  • Avoid stretching with a partner because this can overstretch the shoulder and cause injury
  • Have a coach evaluate stroke mechanics


  • Avoid hitting, serving and repetitive setting if they cause pain.

Gymnastics and cheerleading

  • Avoid handsprings, tumbling passes, walkovers or other weight-bearing stunts.
  • Avoid handstands, push-ups, punches and giants if they cause pain.

Rotator cuff tendonitis

The rotator cuff is a group of four muscles that surround the shoulder and help stabilize it during overhead activities. Rotator cuff tendonitis is pain and inflammation in the tendons of the rotator cuff typically caused by repetitive activities, like throwing. It can usually be treated with rest, along with ice and anti-inflammatory medicine. If you continue to use your shoulder when you have rotator cuff tendonitis, you’ll risk a rotator cuff tear.

Glenohumeral Instability

When rotator cuff muscles are overused, they may not be able to effectively stabilize the shoulder—leading to pain and inflammation. This condition, called glenohumeral instability, is common in baseball and volleyball players.


Young athletes with glenohumeral instability will complain of pain in the front, back, top or inside the shoulder during overhead activities, like throwing a ball. There may also be a sense of “shifting” or “popping.”


Treatment of glenohumeral instability includes:

  • Active rest - Reduce or eliminate painful activities until the pain is gone.
  • Pain control - Ice and anti-inflammatory medicine can help control pain.
  • Physical therapy - Physical therapy provides the best chance for a full-recovery. Your physical therapist will help you regain strength and evaluate your throwing motion to identify and correct any issues that may be straining your shoulder. Physical therapy typically lasts six to eight weeks.
  • Surgery - In extreme cases, surgery may be needed.

Little League Shoulder

Little league shoulder is a condition seen too often in young athletes. Repetitive overhead motions, like throwing, can cause pain and even damage to the growth plate.

This overuse injury that is most common in young pitchers. It typically causes pain in the arm while throwing, but in more severe cases can also hurt during non-throwing activities as well. Sometimes, there will also be swelling near the shoulder.

Little league shoulder is typically diagnosed through a physical exam and x-rays to check for widening of the growth plate.


The best way to treat this condition is with rest, ice and anti-inflammatory medicine. Throwing and batting are typically limited for six to eight weeks and a sling may be used to limit motion. Once the growth plate has healed and the pain is gone, physical therapy should be used to restore strength and range of motion and to help guide a gradual return to full throwing.


You can help your child prevent little league shoulder by teaching them proper mechanics, limiting their pitches/throws and making sure they don’t use breaking pitches until their bones are mature enough for it—usually around age 13 or 14.