Swimmer’s Shoulder: Improving Shoulder Mechanics
Imagine trying to row a two-person kayak where the rower on the right is an elite athlete, but the rower on the left is completely exhausted and barely paddling.
To keep the boat moving straight, the stronger rower has to pull twice as hard, over-compensating for every single stroke. At first, you still glide forward, but before long, the boat starts veering off course, energy is wasted, and the overworked side begins to break down.
That unbalanced paddle is similar to what happens inside a swimmer’s shoulder. Swimming builds massive, powerful pulling muscles in the front of your chest and back, but it often leaves the tiny stabilizing muscles behind the shoulder blade completely overworked and outmatched. Repeat that lopsided pulling motion thousands of times per workout, and what starts as a subtle muscle imbalance quietly grinds its way into a sharp, persistent shoulder injury.
At Lake Country Physiotherapy in Orillia, we work with swimmers of all levels who are dealing with this exact struggle. Understanding how swimmer’s shoulder develops, why shoulder mechanics break down, and how to fix the underlying physical strain is the key to staying strong and pain-free in the water.
What Is Swimmer’s Shoulder and Who Does It Affect?
“Swimmer’s shoulder” is an umbrella term used to describe progressive shoulder pain caused by repetitive overhead arm movements. It isn’t caused by a sudden, dramatic fall or a single heavy impact. Instead, it is a microtrauma injury, a condition that sneaks up on you gradually as tiny, unhealed strain builds up in the soft tissues around the joint.
While it is most famous among competitive lap swimmers, this condition also affects water polo players, triathletes, kayakers, and even recreational swimmers who suddenly step up their weekly pool workouts.
Swimmer’s shoulder is extraordinarily common. In fact, shoulder pain stands as the single most frequent orthopaedic issue in the sport, with clinical research published in the Journal of Athletic Training reporting that anywhere from 40% to 91% of competitive swimmers experience it at some point in their careers.
The Anatomy: What Is Actually Happening Inside
Historically, almost any pain at the front or top of a swimmer’s shoulder was labeled “subacromial impingement”, a term that suggested a shoulder bone was physically pinching down or grinding away at a tendon every time you reached overhead.
Modern sports science has given us a much clearer (and far more reassuring) picture.
Compression inside the shoulder joint is completely normal. Every time you raise your arm, tissues naturally compress. Pain doesn’t happen because your joint is “too tight” or structurally broken; it happens when the rotator cuff tendons and surrounding tissues become overworked and under-prepared for the volume of laps you are swimming.
Today, physiotherapists refer to this condition as Rotator Cuff–Related Shoulder Pain. Rather than a structural trap, it is almost always a breakdown in muscular endurance and workload capacity:
1. Rotator Cuff Fatigue
Your rotator cuff is a team of four small muscles whose primary job is to hold the ball of your shoulder centred in its socket. During a long swim workout, these smaller stabilizer muscles tire out long before your massive pulling muscles (like your lats and chest). Once the rotator cuff gets exhausted, it loses its grip, allowing the arm bone to ride slightly up and forward, placing excess stress on the tendons.
2. The “Loose Front, Tight Back” Pattern
Because swimming demands an enormous overhead reach, swimmers naturally develop extra flexibility in the front of their shoulder joint. To balance this out, the rotator cuff and biceps tendon have to work twice as hard to stabilize the arm during your stroke’s “catch” phase. If those muscles aren’t conditioned to handle that extra stabilization work, the tissue becomes irritated and tender.
3. Progressive Tissue Overload
If you keep pushing through that initial irritation, the tissue enters a state of chronic strain. What started as mild muscle fatigue can eventually lead to deeper tendinopathy in the rotator cuff or biceps tendon, making it painful to pull through the water.
Why Swimming Strokes Stress the Shoulder
A proper freestyle stroke requires a delicate dance between your core, upper back, shoulder blade, and arm. When one part of that chain stops pulling its weight, your shoulder joint pays the price:
- Fatigued Shoulder Blade Stabilizers: Your shoulder blade (scapula) acts as the foundation for your entire arm. If the muscles controlling your shoulder blade get tired, the bone fails to tilt properly during the recovery phase of your stroke, narrowing the space inside the joint.
- Body Roll Deficits: Good freestyle swimming relies on rotating your entire torso from side to side. If your core or hips are stiff and you don’t roll your body enough, you are forced to over-rotate your shoulder joint backward to clear the water.
- Hand Entry Flaws: Crossing your hand over the center line of your body when your hand enters the water puts your shoulder into an extreme, vulnerable position that instantly over stresses the rotator cuff.
Rebuilding Healthy Shoulder Mechanics
Fixing swimmer’s shoulder requires more than just sitting on the deck with an ice pack until the aching stops. Once you return to the pool, those same poor mechanics will simply bring the pain right back. Effective recovery focuses on restoring proper activity-load management, strengthening stabilizer muscles, and improving stroke technique.
1. Restore Balanced Muscle Strength
While swimming naturally builds large, powerful pulling muscles (like your lats and chest), it often leaves the smaller, deeper rotator cuff and lower upper-back muscles lagging behind. Performing regular shoulder external rotation exercises alongside low-intensity shoulder extension rows helps re-balance the joint.
2. Improve Scapular Control
Training the muscles that glide and anchor your shoulder blade, specifically your lower trapezius and serratus anterior, ensures your shoulder blade carries its weight each time your arm reaches overhead. Adding Prone IYTs and dynamic shoulder prone swimmers into your dryland warm-up teaches your shoulder blade to stay locked into a stable, supportive position through every phase of your arm sweep.
3. Mobility and Thoracic Rotation
Unlocking stiffness in your mid-back (thoracic spine) allows your upper body to rotate smoothly in the water. Incorporating rotational movement drills like the thoracic open book stretch or half-kneeling windshield wipers before jumping in the pool opens up your chest and mid-spine, taking the pressure off your shoulder.
Keep Swimming Strong in Orillia
A sore shoulder does not mean you have to give up the sport you love, but ignoring that nagging pinching sensation will only turn a temporary tune-up into a long-term injury. By catching microtrauma early and fixing your shoulder mechanics, you can glide through the water efficiently and without pain.
Our treatment team at Lake Country Physiotherapy in Orillia, ON, specializes in overhead sports injuries, biomechanical shoulder analysis, and targeted shoulder rehabilitation. If shoulder pain is slowing you down in the pool, contact Lake Country Physiotherapy today to schedule your assessment and get back in the swim of things.
