Kinetic Chain & Shoulder Injuries

The baseball world was recently abuzz with news that rookie pitching phenom, the Washington Nationals’ Stephen Strasburg, was placed on Major League Baseball’s 15-day disabled list due to “inflammation” and “stiffness” in his shoulder. While patient privacy and other issues often prevent the release of specific injury details, these kinds of symptoms likely indicate a bout with shoulder tendonitis.

Tendonitis is a common condition experienced not just by elite pitchers but by active people in sports such as baseball, swimming, volleyball, weightlifting, golf, even bowling – all activities that involve vigorous or repetitive use of the shoulder. And while the team at Emory Sports Medicine treats all shoulder injuries – with a particular focus on repair of rotator cuff tears – we also investigate the cause of the injury. Quite often, the cause of the injury leads us to a completely different body part.

Let’s talk about the kinetic chain. If you are a pitcher like Strasburg (and congratulations if you are), this is the chain of power generated by your core muscles – abdomen, glutes and the spine. All the power that your arm puts out – a 99 mile per hour fastball – is actually done with the legs. Breakdowns up the stream of this chain – in the shoulder, for instance – often indicate trouble “downstream.” It could mean a specific area of your core is weak or not performing properly. The result: You’re putting too much stress on your shoulder. (You can learn more information on kinetic chain here.)

Whether you’re Stephen Strasburg or a B-Level tennis player, failure to treat this injury and its cause can have permanent results. Tendonitis can lead to rotator cuff tendon degeneration. Tendinopathy – chronic tendonitis – weakens the tendon and leads to tears in the rotator cuff. Partial tears may lead to higher-grade tears until a full thickness tear results. Once this occurs, rotator cuff repair – surgery – is needed. Pitchers like Strasburg rarely return to the mound after surgery for full thickness rotator cuff tears. However, athletes with lower demands than a major league pitcher can frequently return to their sports after rotator cuff repair.

If you have a shoulder injury, the staff at Emory Sports Medicine can help you determine what you’re dealing with – tendonitis, tendinopathy, tears, etc. – and give you a plan to recover. We’ll also investigate your “kinetic chain” and determine the root cause of the problem.

You can bet the 22-year-old Strasburg’s trainers and physicians (not to mention his agent) are making sure he’s treating the injury properly and understanding what’s causing it. He has a valuable and exciting career ahead of him, if he can avoid injuries.

Do you have questions about tendinitis or any shoulder injuries in particular? If so, fire away in the comments section.

About Spero Karas, MD:

Dr. Karas joined the Emory Orthopaedic & Spine Center on February 1, 2005. Prior to that he served as chief of the Shoulder Service, team physician, and director of the Orthopaedic Sports Medicine Fellowship at the University of North Carolina at Chapel Hill Department of Orthopaedics. In addition to his role as director of the Orthopaedic Sports Medicine Fellowship Program at Emory, he serves as a consulting team physician for Georgia Tech and Emory University Athletics.

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  • Kathy

    I have dealt with shoulder pain for years. Impingement syndrome and tendonopathy. What can one do to prevent further tendonopathy? Is it just a matter of aging? Where can I learn more about the kinetic chain? Thanks Kathy S

    • Dr. Karas

      Tendinopathy is an overuse and age related process that is largely programmed into our DNA but with environment also playing a role. Avoiding repetitive injury, proper rest, and physical therapy are the best way to keep the condition at bay. There is no known “cure”. There are a number of online resources for information on the kinetic chain.