Three words that a baseball player never wants to hear. Internal shoulder impingement can be one of the most debilitating and frustrating injuries for baseball players, especially pitchers.

The Shoulder Anatomy

Before explaining internal shoulder impingement, it is essential to understand some basic shoulder anatomy. The shoulder comprises 3 bones: the scapula, humerus, and clavicle. In addition to these 3 bones, both small (rotator cuff) and large (deltoids, lats, trap, rhomboids, pecs) muscles allow the shoulder to function. Other important structures to make a note of are the labrum, which essentially functions to deepen the socket of the shoulder joint creating more stability, and bursae, which are fluid-filled sacs that aid to lubricate the shoulder.

What Is Internal Shoulder Impingement?

When Internal shoulder impingement (also known as thrower’s shoulder) occurs, the tendons of the rotator cuff, most commonly the supraspinatus tendon, as well as the subacromial bursa become impinged and inflamed from repetitive overhead motions such as throwing a baseball. After throwing a baseball over and over, the muscles that stabilize the shoulder blade can become weakened. When this happens, the shoulder blade does not move properly, causing the tendon and bursa previously mentioned to become compressed between two bones in the shoulder. While shoulder impingement may be the diagnosis, there can be underlying issues that cause it; many times, shoulder impingement is a sign that something else in your shoulder is either injured or not functioning properly. Some common causes of shoulder impingement are scapular dyskinesis, labral pathology, rotator cuff pathology, and shoulder instability.

Common Signs And Symptoms Of Internal Shoulder Impingement

The shoulder is one of the most complex joints in the body due to its degrees of freedom and need for such great stability. While every athlete is different and every case can present different from the last, I will highlight some of the more common signs and symptoms of internal impingement. The first and most important thing in treating internal shoulder impingement is to find the cause. As stated before, internal shoulder impingement may be a sign that something in the shoulder is injured or not functioning properly. A clinician in sports medicine such as an athletic trainer, orthopedic physician, sports medicine physician, etc., is best to conduct this evaluation. Symptoms consistent with impingement include sharp pain in the top of the shoulder and increased pain when lifting the arm overhead. Some key findings in an assessment may include scapular dyskinesis (improper shoulder blade movement), bad posture (i.e., rounded shoulders), pain with active and passive shoulder flexion and abduction, pain and weakness with resisted external rotation at 90°, and positive Neer and Hawkins-Kennedy tests.

Depending on the medical exam findings, the provider may want to order additional tests such as an x-ray or an MRI to further evaluate the shoulder. As long as there is no injury that requires surgery, rehab is begun immediately to treat the underlying cause of the impingement.

How Do You Treat Internal Should Impingement

The most important part of rehab is to remove the cause of the problem; so, if throwing a baseball is causing pain, unfortunately, throwing will have to be put on hold for several weeks. As annoying and aggravating as this can be for a baseball player, this is necessary for successful rehab. Conservative rehab may be needed for up to 4-6 weeks before beginning a throwing program. The throwing program can range anywhere from 2-12 weeks, depending on several factors such as length of time taken off from throwing, time of the season, position, severity of the injury, etc.

Early stages of rehab typically focus on regaining a full, pain-free range of motion and correcting bad posture if necessary. For many individuals, especially baseball players, having rounded shoulders is common. As mentioned previously, having bad posture does not allow the shoulder blades to move properly, resulting in impingement. Exercises that focus on stretching tight muscles (usually lats and pecs) and strengthening weak muscles (usually mid traps and rhomboids) will correct this and allow the shoulder blades to move properly. Many exercises can address poor posture while strengthening muscles, and vice versa, so it is best to choose exercises that do just that.

Once posture is corrected and sufficient range of motion and strength are achieved, the next phase of rehab is to focus on dynamic stability of the shoulder. To throw a baseball 95+ MPH, the shoulder has to rotate at around 8000 degrees per second. All shoulder muscles must work synchronously for this to happen or injury can occur.

In cases where pain and inflammation are not controlled through rehab exercises, anti-inflammatory medications or steroid injections may be given. In cases where medication and injections do not provide relief, surgery may be warranted. The most common impingement surgery is called a subacromial decompression, where one of the shoulder ligaments is cut to decompress the area where the impingement is happening. Age, position, level of competition, time of season, and many other factors will play into the decision of whether surgery is appropriate or not.

How To Prevent Internal Shoulder Impingement

Treatment and prevention are very similar; ensure full, pain-free range of motion, maintain good strength and stability, and keep inflammation to a minimum. While some exercises are good for most athletes, it is best to individualize each program if possible. The thrower’s ten program is a good exercise routine to set a foundation. These exercises will focus on strengthening both the small and large muscles of the shoulder. It is important to focus on tempo and form when performing these exercises to ensure the correct muscles are being targeted.

It is also important to determine when each athlete should perform these exercises. Some athletes prefer to do them before activity, some after, and some both. Doing exercises before throwing is good to activate your muscles, while performing them afterward is good for restoring proper movement patterns in the shoulder. Each athlete needs to figure out what works best for them. Other things to consider when determining exercises, sets, and reps for a certain day are activity level for that day and the following days. For heavier workload days (i.e., heavy upper body lift, bullpen days, game days), doing a lower number of sets and reps is typically best, and higher sets and reps for light workload days. While it is always a good idea to go into a day with a plan, understand that the plan needs to be fluid. If the plan was to have a heavy workload day, but the athlete is sore from the previous day, the plan should be adjusted accordingly.

Another important aspect of preventing impingement is to keep inflammation to a minimum, which is much easier said than done. Shoulders were not built for overhead motion, especially the forces generated from rotating at 8000 degrees per second to throw a five-ounce ball 95+ miles per hour over and over again. There are several things that can be done to help control inflammation. Eating a healthy diet that excludes all foods that cause inflammation is very important. Additionally, after heavy throwing days striders and/or short distance sprints (30-90ft) are an excellent way to get the shoulder moving and increase blood flow to the area. This floods the area with nutrients to help repair the wear and tear on muscles as well as reduce inflammation.

A topic that has been under discussion over the last few years is whether to ice or not. I don’t want to spend too much time on this as this deserves a long discussion, but I am indifferent when it comes to icing. While those that are for icing will say that it is beneficial as it helps reduce pain and swelling, those that are against it will say that ice causes the blood vessels to constrict which decreases blood flow. By reducing blood flow, the area becomes deprived of nutrients that it needs from the blood, which reduces healing. When it comes to icing, I recommend athletes listen to their bodies. If icing makes them feel better, then they should do it.

Conclusion

Many factors play into the treatment of internal shoulder impingement, from finding the cause to exercise selection to trying to keep inflammation to a minimum. Every athlete is different, every case is different, and every treatment needs to be different. Keeping muscles strong and inflammation down will give all athletes a good chance of preventing impingement from happening.

• Not all exercises are appropriate for each individual. Individuals should consult an expert in the field of sports medicine before beginning a rehab regimen*
• Heavy throwing day example – 1 set x 10 reps
• Light throwing day example – 2 sets x 8-10 reps
• Resistance should be challenging but able to perform with proper form

Sources

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• Spritzler, Franziska “The 13 Most Anti-Inflammatory Foods You Can Eat.” Healthline, Dec. 2019, https://www.healthline.com/nutrition/13-anti-inflammatory-foods