Swimmer’s shoulder is one of the most common complaints I see in the pool community. Here’s what’s actually happening when it strikes.
Nearly all my small talk eventually leads to “so when did you decide you wanted to be a physical therapist?” I’ve gotten that question a hundred times, and I give everyone the same answer: “I knew as a freshman in high school.”
I count myself lucky to have found my passion early. I come from a family of athletes, swimmers specifically, and my parents shuttled me between practices five or six nights a week. I’d go from swim to soccer to basketball, then right back to swim. I ate dinner and did homework in the car just to keep doing it all. I played almost every sport growing up, but swimming was the constant, and swimming is what led me to physical therapy at just 14.
Swimmer’s Posture
As a group, swimmers don’t have the best posture. Watch any major meet and you’ll spot the forward head and rounded shoulders everywhere. You’ll start noticing it in the general population too. That posture is exactly what landed me in PT. I was a freshman swimming two practices a day on top of lacrosse, and I began to feel pain along the side of my shoulder that radiated halfway down my arm. Raising my arms overhead made it worse.
The Diagnosis: Swimmer’s Shoulder
I had textbook swimmer’s posture: an overdeveloped chest and a weak mid-back. That imbalance pinched one of my rotator cuff tendons, which created the pain in my shoulder and arm.
The Technical Term: Upper Crossed Syndrome
This is categorized by the following tight/overdeveloped musculature and weak/inhibited musculature with the addition of the Latissimus Dorsi as “tight” in the swimming population.
The Breakdown
Most swimming strokes fire the front of the chest and the shoulder’s internal rotators. The big players are the pectoralis major and the latissimus dorsi. The pec major adducts and internally rotates the humerus. The lats extend, adduct, and internally rotate the shoulder. In plain terms: the two muscles you rely on most in the water are the same ones that pull your shoulders forward.
Why It Hurts
Once the shoulder sits in that adducted, internally rotated position, the supraspinatus tendon gets pinched between the acromion and the head of the humerus. The supraspinatus already sits in a vulnerable spot as it runs under the acromion to reach the humerus. Adducting and internally rotating the shoulder shrinks the space beneath the acromion, and lifting the arm overhead shrinks it further. Less space means the tendon pinches more easily, which produces the pain pattern in the diagram below.
