Repetitive stresses from throwing rotation can cause damage

There is a delicate balance between shoulder mobility and stability. Throwers need enough mobility to reach extreme positions of rotation to generate high velocity, yet they must maintain enough stability to have a stable platform for that rotation. Throwers’ shoulders anatomy sometimes adapts to the repetitive forces put on them. The humerus (upper arm bone) often rotates slightly backwards with time, and the soft tissue of the joint, called the capsule, often stretches out in the front of the joint. Throwers often gain rotation backwards when cocking to throw a ball and lose forward rotation on follow through. This imbalance creates repetitive stresses on the shoulder labrum and rotator cuff tissues.

During the throwing motion, the muscles of the scapula (shoulder blade) and rotator cuff must work to keep the humeral head centered on the socket. As the shoulder fatigues, the scapular motion increases detrimentally, and the shoulder rhythm gets disrupted. This can lead to shoulder impingement, when the rotator cuff tendons get abraded by bony socket and scapula.

With time, this rubbing of the tendons on bone can create tears of the rotator cuff, causing weakness and shoulder pain. This is diagnosed by physical exam tests and MRI.

Non-operative treatment includes antiinflammatory medicines, rest, ice/heat, physical therapy (sleeper stretches, resistance band strengthening, scapular exercises), and sometimes steroid injections. This is successful in 90% of throwers.

Surgical treatment involves removing some of the scapular bone to create more room for the rotator cuff tendons, debriding the torn portion of the tendons, and sometimes placing sutures across significant tendon tears to repair them. Surgical treatment will allow approximately 75% of pitchers to return to pitching, but only 50% return to the same level of sport.

Tears of the shoulder labral tissue can also occur, called SLAP tears. These tears of the top of the labrum occur where the long head of the biceps tendon attaches to the labrum. The labrum is the soft tissue lining around the bony socket of the shoulder which keeps the ball in place on the socket. The biceps tendon peels the labrum off the top of the glenoid bone with repetitive throwing, creating a tear in the labral tissue.

Throwers will notice a loss of velocity and a deep shoulder pain often when cocking back to throw. Sometimes a clinking or snapping sensation in the shoulder can be felt, and the shoulder can feel unstable to the thrower. MRI studies are used to confirm the diagnosis. Conservative treatment is similar to rotator cuff tear treatment. If surgery is required, the labral tissue is re-attached to the glenoid bone using suture anchor devices.

Surgery results in return to the same level of pitching in 60-80% of cases.

Little league shoulder is an overuse injury caused by stress to the growth plate of the humerus. This is most commonly seen in youth overhand pitchers ages 11 to 16. Causes of this injury include poor throwing mechanics, muscle imbalance and repetitive overhand throwing without proper rest. The child will often describe deep shoulder pain and weakness. There is a risk of growth plate damage if left untreated. Thankfully, the vast majority of these cases will improve with proper rest and avoidance of throwing. Once pain free, throwers can gradually return to their sport after participating in a formal throwing program supervised by a physical therapist.

Ways to prevent overuse throwing injuries include:

• Warming up properly with stretching and easy, gradual throwing

• Rotating playing different positions, other than just pitching

• Avoid playing on multiple teams with overlapping seasons

• Avoid all throwing for at least two to three months of the year

• Don’t continue throwing if experiencing pain

• Master the fastball first before considering breaking pitches

• Follow appropriate rest and pitch count guidelines Recommended pitch counts by age and associated rest periods (see diagrams below)

Carlton Houtz, M.D., is an orthopaedic sports medicine surgeon at Highland Clinic Center of Orthopaedics and Sports Medicine, who routinely treats sports injuries. Appointments can be made by calling (318) 798-4623. The Highland Clinic Orthopaedic offices are located at 1455 E. Bert Kouns Industrial Loop, Suite 210, Shreveport, LA 71105. Visit https://www.highlandclinic.com/staff/carlton-houtzm-d for more information.