Blog 12: The Overuse Injuries Playbook (Final)
Part 12: Shoulder Pain (Swimmer's Shoulder): Why Your Shoulder Hurts and How to Fix It Before It Sidelines You
Welcome back to The Overuse Injury Playbook. I'm Dr. Keirstyn, a chiropractor and endurance coach. In this series, we are breaking down the most common injuries that sideline athletes. In Part 1, we covered plantar fasciitis, in Part 2, we tackled Achilles tendinopathy, in Part 3, we broke down shin splints, in Part 4, we looked at runner's knee, in Part 5, we covered IT band syndrome, in Part 6, we looked at meniscus injuries, and in Part 7, we covered stress fractures, and in Part 8, we looked at high hamstring tendinopathy in Part 8, we looked at high hamstring tendinopathy, and in Part 9, we covered groin and adductor strains and in Part 10, we looked at hip flexor strainsand in Part 11, we covered lower back pain. Today, we are diving into the nagging ache that makes every swim stroke feel harder than it should: shoulder pain, specifically swimmer's shoulder.
It starts as a dull ache at the front of your shoulder during a swim. At first, you only notice it in the last few hundred meters of a long set, when fatigue sets in and your stroke mechanics start to break down. But as the weeks go on, the ache shows up earlier. Soon, it hurts to reach overhead, and you feel a pinch every time you pull through the catch phase. You might even notice that your shoulder feels stiff and weak when you get out of the pool, and it takes hours to loosen up.
This is swimmer's shoulder, and it is one of the most common overuse injuries in triathletes and swimmers. The frustrating part is that it often gets better with a few days off, only to come back the moment you ramp up your swim volume again. That cycle repeats because the pain resolves, but the underlying drivers do not.
What Swimmer's Shoulder Actually Is
Swimmer's shoulder is an umbrella term covering several presentations, all driven by repetitive overhead motion with poor mechanics. The most common issues I see are rotator cuff impingement, rotator cuff tendinopathy, and biceps tendinopathy.
Your rotator cuff is a group of four muscles that stabilize your shoulder joint and control the position of your upper arm bone in the socket. Every time you take a stroke, your rotator cuff muscles work to keep your shoulder stable while your larger muscles like the deltoid and lats generate power.
Rotator cuff impingement occurs when the space between your upper arm bone and the bony roof of your shoulder narrows, pinching the rotator cuff tendons and the bursa. This creates inflammation, pain, and eventually tendon damage if left untreated.
Rotator cuff tendinopathy develops when swim volume increases too quickly or when stroke mechanics break down under fatigue. The tendons are overloaded beyond their adaptive capacity, leading to pain, weakness, and loss of function.
Biceps tendinopathy shows up as pain at the front of the shoulder, often worse with the catch phase. It frequently accompanies rotator cuff issues as a secondary structure under excess load.
Why Your Shoulder Is Overworking
Shoulder pain in swimmers and triathletes is rarely just about the shoulder itself. It is usually a sign of weakness and instability elsewhere in the chain.
Poor Stroke Mechanics: Entry hand crossover, dropped elbow at catch, and inadequate body rotation are the mechanical culprits I see most. In triathletes who swim less frequently than pure swimmers, technique tends to be less refined and compensation patterns more pronounced.
Weak Rotator Cuff and Scapular Stabilizers: If your rotator cuff and shoulder blade muscles are not strong enough to stabilize your shoulder through thousands of repetitive strokes, the larger muscles take over and the smaller stabilizers get overloaded.
Poor Posture from Desk Work: If you spend most of your day sitting with rounded shoulders and a forward head posture, your shoulder blade position is already compromised before you even get in the pool. This creates impingement and reduces the space available for your rotator cuff tendons.
Sudden Increases in Swim Volume: Ramping up your swim volume too quickly without adequate preparation is one of the most reliable injury triggers available. The shoulder structures are under repetitive load that accumulates across a training season.
Training Through Fatigue: For sprint and Olympic distance triathletes, the swim is shorter but often swum at a higher relative intensity, which means mechanics break down faster and the shoulder is loaded at a greater rate for the distance.
How to Actually Fix Swimmer's Shoulder
To heal swimmer's shoulder, we must reduce the irritation and build the strength and stability your shoulder needs to handle the load.
Manage the Load: Avoid activities that cause sharp pain or a lingering ache. If swimming hurts, reduce your volume and intensity. Focus on technique drills at lower intensity rather than high volume sets. If swimming is too painful, swap it for kicking or pull buoy work with paddles removed to maintain your aerobic fitness without aggravating your shoulder.
Fix Your Stroke Mechanics: Work with a coach to address entry hand crossover, dropped elbow at catch, and inadequate body rotation. Small changes in your stroke can make a massive difference in how your shoulder is loaded.
Build Rotator Cuff Strength: Your rotator cuff muscles are the primary protective mechanism for your shoulder. Incorporate external rotation exercises and scapular stabilization work to build the strength your shoulder needs to handle repetitive overhead motion.
Improve Scapular Control: Your shoulder blade must move properly to create space for your rotator cuff tendons. Incorporate exercises that teach your shoulder blade to move in coordination with your arm, ensuring your shoulder is stable through the full range of motion.
Address Posture: If you spend most of your day sitting with rounded shoulders, your shoulder blade position is already compromised. Work on thoracic extension and scapular retraction to restore proper posture and create space for your rotator cuff tendons.
Manual Therapy: In the clinic, I use soft tissue therapy and joint mobilizations to restore proper movement to your shoulder, shoulder blade, and thoracic spine, ensuring your shoulder is moving efficiently. I also assess your stroke mechanics to identify any compensations that are contributing to the pain.
What to Watch For
If your shoulder pain is accompanied by numbness, tingling, or weakness in your arm, it is a sign that the issue may involve nerve compression. These are red flags that require immediate attention.
Also, if you have been stretching your shoulder aggressively and the pain is getting worse, stop. Overstretching an irritated shoulder can delay healing and create more instability.
Final Word
Swimmer's shoulder is a sign that your stroke mechanics, rotator cuff strength, and scapular control need attention. By addressing the root cause, you can get back to swimming with a full, powerful stroke.
This wraps up The Overuse Injury Playbook. We have covered the most common overuse injuries in endurance athletes, from plantar fasciitis to swimmer's shoulder. The pattern is consistent: pain is the messenger, not the problem. The fix is not rest alone, but building the strength, mobility, and movement quality your body needs to handle the load.
Struggling with shoulder pain that keeps coming back? Book an assessment with me, Dr. Keirstyn, at Endurance Therapeutics. Let's find the root cause and build a plan to get you back to training pain free.
📍 Endurance Therapeutics | Oakville, Ontario
📞 905-288-7161