You’ve Heard Of Tennis Elbow, But What About Tennis Shoulder? (Part II)
The Kinetic chain
Upper extremity throwing motions, tennis swings, baseball and softball batting, and just about all athletic movements involving the upper extremity build the strength and power from the legs. This transfer of energy through the body is only possible through a stable core. Without core stability, the arms compensate by working harder, potentially contributing to overuse or traumatic injury at the shoulder and elbow.
In the article, “Understanding the kinetic chain in tennis performance and injury,” Dr Ben Kibler, Medical Director at the Shoulder Center of Kentucky, reports as little as 13% of the total kinetic energy for a tennis serve is derived from the the shoulder.(1) In a normal functioning kinetic chain, up to 55% of the force is kinetic energy derived from the legs.(1)
Posterior shoulder impingment (PSI)
Check out last week’s SciSport Blog post to catch up on the anatomy and mechanisms involved in PSI. This week’s post will continue with symptoms and treatment of PSI from a tennis athlete clinical case presented in the article “Posterior Shoulder Instability in Tennis Players: Aetiology, Classification, Assessment and Management”.(2)
what does PSI feel like?
Symptoms of PSI include vague or sharp pain in the back of the shoulder. This happens because the humeral head shifts towards the back with in the shoulder joint. The rotator cuff, capsule, labrum, and biceps tendon can all become impinged or compressed. PSI can develop from poor shoulder mechanics as well increased activity. Pain is often accompanied by clicking, sliding, or feelings of “looseness”
how to test for PSI
To test for PSI, a therapist should manually correct for scapular and humeral head movements during flexion and horizontal adduction. If correction of these movements reduces pain and symptoms, this could be a large indicator of PSI. In addition, a therapist can use any of the following tests:
Posterior apprehension test (sensitivity 19.2%. specificity 99.2%)
Kim test (sensitivity 80%. specificity 94%)
Posterior drawer test (sensitivity 42%. specificity 92%)- tests for instability, not specifically PSI
How to Treat PSI
Non-surgical management can vary between 3-6 months and is most effective if no structural damage is present. If structures in the shoulder are damaged, surgery may be warranted. The goal of the physical therapy program is to restore normal shoulder mechanics to prevent the abnormal movement of the arm in the shoulder joint. The rotator cuff will need to be strengthened, and movements in the kinetic chain should be optimized to reduce the overall workload on the shoulder. An exercise program should address the following components:
Scapular motor control
External rotation (initiate from neutral and progress to an internally rotated starting position)
Internal rotation (to be added only after external rotation is controlled; internal rotation stresses the backside of the shoulder joint)
Scapular strengthening - rows and resisted range of motion (starting with extension and progressing to include flexion)
Sport specific functional tasks - added in the later stage of the rehab program
Struggling with shoulder pain or weakness? Play an overhead, racquet, or throwing sport? Book a session with our sports physical therapist or sports performance coach today!
If you’ve had an injury and are in need of a return to play program, schedule a physical therapy session with us to get back to your sport. Get back in the game ready to meet your sport specific demands.
References:
Kibler WB. Understanding the kinetic chain in tennis performance and injury. Aspetar Sports Medicine Journal. 2014;3:492-497.
Watson L, Hoy G, Wood T, et al. Posterior Shoulder Instability in Tennis Players: Aetiology, Classification, Assessment and Management. IJSPT. 2023;V18(3):769-788.
Disclaimer: This SciSport blog post is a summary of an article printed in an academic research journal. The purpose of this blog post is to provide readers with academic and educational content in an easy-to-understand format. We take no credit for the material and knowledge presented, and we encourage readers to take a look at the original source provided in the References section
