It is no surprise that athletes who participate in overhead sports such as baseball, softball, swimming, volleyball, tennis and other repetitive throwing sports are at higher risk for developing shoulder injuries.
The shoulder is comprised of two primary joints: the glenohumeral (GH) joint, acromioclavicular (AC) joint and scapulothoracic joint. The glenohumeral joint is an extremely mobile joint. It is a “ball and socket” joint that consists of the head of the humerus (the upper arm bone that acts as the ball) and the glenoid (socket). Its mobility comes in handy in developing the forces necessary to throw a baseball or spike volleyball at a high velocity.
However, the amount of motion allowed in the glenohumeral joint can sometimes compromise its stability. Surrounding the outside edge of the glenoid is a rim of soft fibrous tissue called the labrum, which creates a “suction” to keep the head
of the humerus aligned in the glenoid socket. The ligaments, tendons and muscles (such as the glenohumeral ligaments, rotator cuff and biceps tendons) surrounding the shoulder joint further provide stability and alignment to the joint.
Athletes’ repeated use of their arm at high speeds significantly stress the stabilizing structures. The following are some of the most common injuries seen in the overhead athlete. Unfortunately, seasoned athletes are at higher risk for developing more than one of these injuries due to overuse.
SLAP Tears (Superior Labrum Anterior to Posterior)
This is a tear at the top (S – superior portion) of the glenoid labrum. The tendon of the long head of the bicep, which forms the biceps muscle of the upper arm, actually attaches and inserts at the superior labrum. The anterior/posterior (AP) refers to the fact that the tear likely extends in front of and behind the insertion of the biceps tendon (if you think of the glenoid as the face of a clock, the tear would be from 10 o’clock to 1 o’clock).
SLAP tears typically occur from the force on the biceps tendon from throwing. This in turn can pull at its attachment site to the labrum. Common signs and symptoms of a SLAP tear include clicking, catching and locking sensations and pain described as “deep” within the shoulder, particularly with overhead motion.
Biceps Tendonitis and Tendon Tears
As mentioned above, the long head of the biceps tendon attaches on the top of the glenoid labrum and runs down the front of the shoulder joint. Repetitive motions such as throwing and serving in overhead sports can cause irritation, inflammation or tearing to this tendon. Common signs and symptoms of biceps tendonitis include:
- Pain and tenderness in the front of the shoulder (bicipital groove)
- Popping or snapping sensation
Rotator Cuff Tendonitis and Tendon Tears
The rotator cuff is comprised of four muscle and tendons:
- Teres minor
In addition to internal and external rotation movements of the shoulder, the rotator cuff works to keep the humeral head depressed (down) and in place during motion. Repetitive use, as seen in overhead sports, can cause irritation or inflammation of these tendons.
The most common tendon to be affected is the supraspinatus. The supraspinatus plays a large role in lifting the arm away from the body. As irritation worsens, the tendon can tear.
Symptoms of rotator cuff tendonitis and tears include:
- Radiating or referred pain
- Pain in the back of the shoulder and deltoid
- Pain at night
- Loss of range of motion
Glenohumeral Internal Rotation Deficit (GIRD)
To throw at high speeds, extreme external rotation of the shoulder is needed to occur. This causes the front of the shoulder to become stretched out. This in turn causes shortening or tightening of the posterior shoulder structures, particularly the capsule. This imbalance can lead to a change in mechanics, thus putting greater stress and abnormal forces on the labrum and rotator cuff.
Typically, symptoms include:
- Shoulder pain with or without elbow pain
- Pain with overhead activity
- Tightness in the chest muscles
- Winging of the scapula
- Loss of throwing velocity
GIRD can be evaluated by measuring internal and external rotation of both the dominant and non-dominant shoulder. A loss of greater than 20 degrees of internal rotation in the dominant shoulder can indicate GIRD.
If you suspect you have a shoulder injury, a thorough history and physical exam by a sports medicine orthopedic surgeon is the first step in obtaining a proper diagnosis. They may or may not order an X-ray to rule out other causes of pain such as fracture, growth plate injury, arthritis or bone spurring. The mainstay of treatment is conservative management.
If no improvement is seen, an MRI (magnetic resonance imaging) or MRI arthrogram may be ordered. An MRI arthrogram is usually ordered to evaluate for labral tears. Contrast dye is injected directly into the shoulder joint using ultrasound or x-ray for guidance. These studies are useful because the dye will “fill in” any tears that may be present, making it more visible for the physician.
Usually, the initial treatment includes a conservative approach of activity modification, ice, anti-inflammatories and physical therapy. A cortisone injection may sometimes be offered. If no improvement is seen within 6 to 12 weeks, surgical intervention may be indicated. Many injuries can be avoided with proper rest and a strength and conditioning program.
If you or a loved one has sustained a sports injury to the shoulder, request an appointment with one of our sports medicine experts.