Swimmer's Shoulder: Causes, Symptoms, and Physical Therapy Treatment

July in San Antonio means pools, early morning lap sessions, summer sports leagues, and outdoor fitness routines. For many swimmers and active adults, July also marks the beginning of a dull, persistent ache deep in the shoulder that worsens with every overhead movement. If your shoulder has been bothering you since you picked up your summer workout routine, swimmer’s shoulder may be the reason.

Swimmer’s shoulder is the most common injury among swimmers and one of the leading causes of overhead shoulder pain in active adults during the summer months. The good news is that it responds extremely well to physical therapy when treated early. At Physical Therapy of SA in Live Oak, TX, our team helps swimmers and summer athletes recover from shoulder injuries and get back to full activity all season long.

What Is Swimmer’s Shoulder?

Swimmer’s shoulder is an umbrella term for shoulder pain caused by the repetitive overhead motions involved in swimming strokes, particularly freestyle, butterfly, and backstroke. The clinical term for the underlying problem is shoulder impingement syndrome, also called rotator cuff impingement. With every overhead arm movement, the tendons of the rotator cuff pass through a narrow channel between the top of the upper arm bone and the shoulder blade. When this space becomes too narrow due to muscle imbalance, poor mechanics, or inflammation, the tendons become pinched with every stroke. Over time, repeated pinching causes tendon irritation, inflammation, and pain.

Swimmer’s shoulder is not exclusive to competitive lap swimmers. Recreational pool swimmers, water aerobics participants, and anyone performing repetitive overhead movements in the gym, such as pull-ups, shoulder presses, or overhead throws, can develop the exact same condition through the same mechanism.

Swimmer’s Shoulder Symptoms

Common Symptoms to Recognize

The symptoms of swimmer’s shoulder tend to develop gradually rather than appearing suddenly, which is part of why many people push through them until they become significant:

• Deep, aching pain at the front or top of the shoulder during or after swimming
• Pain that intensifies when raising the arm overhead, reaching across the body, or rotating the arm inward
• Shoulder pain after swimming that worsens at night or disrupts sleep
• Noticeable weakness in the arm during freestyle pull or other overhead movements
• A catching, clicking, or grinding sensation in the shoulder joint during arm rotation
• Pain that begins as mild soreness after long sessions and progressively worsens over the summer if left untreated

Where Does a Swimmer’s Shoulder Hurt?

The location of your pain provides important clues about which structure is involved:

• Front of the shoulder near the top of the arm bone: Likely rotator cuff tendon or biceps tendon irritation
• Outer side of the shoulder: Often subacromial impingement where the tendon is being pinched under the shoulder blade
• Deep inside the joint with a catching sensation: May suggest labral involvement requiring closer evaluation

A physical therapist can pinpoint the exact structure causing your pain through clinical testing, and in most cases, imaging is not needed to begin an effective course of treatment.

What Causes a Swimmer’s Shoulder?

Repetitive Overhead Stroke Mechanics

The sheer volume of shoulder movement involved in swimming is significant. Each freestyle lap requires roughly 16 shoulder rotations per 25 meters. A swimmer completing a moderate 1,000-meter session performs approximately 800 to 1,000 overhead shoulder rotations in a single workout. Multiply that across multiple sessions per week and the cumulative load on the rotator cuff tendons becomes enormous. The impingement occurs at the top of the arm bone swing, the moment when tendons pass through their narrowest space inside the joint.

Muscle Imbalance: The Root Cause Most Swimmers Do Not Know About

Swimmers consistently overdevelop the internal rotator muscles, primarily the pectorals and latissimus dorsi, because these are the muscles doing most of the work during the power phase of each stroke. Meanwhile, the external rotators and scapular stabilizers, the muscles responsible for keeping the shoulder in proper alignment during overhead motion, remain relatively underdeveloped. This imbalance gradually pulls the shoulder into a forward, rounded position that narrows the space rotator cuff tendons pass through. Core weakness compounds the problem by forcing the arms and shoulders to compensate for instability through the trunk.

Poor Stroke Technique

Even small technical errors significantly increase impingement risk. A crossover hand entry in freestyle, where the hand crosses the centerline of the body rather than entering in line with the shoulder, is one of the most common technical culprits. Dropping the elbow during the underwater pull phase and overreaching on entry also create mechanical stress absorbed by the tendons with every repetition.

Training Errors

Sudden increases in weekly yardage, insufficient recovery time between sessions, and heavy use of high-impingement strokes like butterfly without adequate shoulder conditioning are common training-related contributors to swimmer’s shoulder development.

Shoulder Pain From Summer Workouts: Not Just Swimmers

Swimmer’s shoulder shares the same impingement mechanism as many overhead workout injuries that peak in July. If you are not a swimmer but have developed shoulder pain this summer, consider whether any of these activities have increased in your routine:

• Pull-ups, lat pulldowns, and overhead pressing at outdoor or indoor gyms
• Baseball, softball, and football throwing in summer leagues
• Tennis and pickleball serving and overhead shots
• Repetitive overhead yard work such as pruning, painting walls, or lifting
• Paddleboarding and kayaking, which place sustained rotational load on the shoulder

The physical therapy approach that resolves swimmer’s shoulder applies equally to shoulder pain from any repetitive overhead sport or summer workout.

Swimmer’s Shoulder Exercises and Self-Care

Exercises to Strengthen the Muscles Swimmers Neglect

• Prone Y, T, and W raises: Performed lying face down, these target the lower trapezius and scapular stabilizers that swimmers chronically underuse. These muscles are critical for keeping the shoulder blade in proper position during overhead motion.
• Side-lying external rotation: Targets the infraspinatus and teres minor, the two rotator cuff muscles responsible for balancing the overdeveloped internal rotators. This is one of the most important exercises for any overhead athlete.
• Band pull-aparts: A resistance band pulled apart horizontally in front of the body builds posterior shoulder strength and improves scapular retraction.
• Doorway chest stretch: Loosens tight pectoral muscles that pull the shoulder forward into the rounded posture that sustains impingement. Hold each side for 30 to 45 seconds.
• Sleeper stretch: Improves flexibility in the posterior shoulder capsule, which stiffens in frequent swimmers and restricts internal rotation range.

How to Relieve Shoulder Pain After Swimming

• Apply ice to the shoulder for 15 minutes after each session during active flare-ups to reduce inflammation
• Avoid overhead activity and specific strokes that reproduce your pain until you have been evaluated
• Adjust your sleep position to avoid lying on the affected shoulder overnight
• Use a supportive pillow to keep the shoulder in a neutral position, as nighttime compression slows tissue recovery

Best Swimming Stroke for Shoulder Injury Recovery

Backstroke is typically the most shoulder-friendly stroke for recovery because it involves less internal rotation and produces less subacromial compression than freestyle or butterfly. Breaststroke places less overhead demand on the shoulder but requires careful attention to arm recovery mechanics.

Freestyle and butterfly are the highest-risk strokes during recovery and should be modified or temporarily paused, particularly if crossover hand entry or incorrect elbow positioning contributed to the injury. Stroke modification is a formal component of the return-to-swimming program at Physical Therapy of SA, and your physical therapist will advise on safe in-water activity at each stage of your recovery.

How Physical Therapy Treats Swimmer’s Shoulder

Self-care and rest may quiet the symptoms temporarily, but swimmer’s shoulder recurs unless the underlying muscle imbalances and movement mechanics are corrected. At Physical Therapy of SA in Live Oak, TX, our physical therapists treat the root cause so your shoulder heals completely and performs reliably through the rest of the summer and beyond.

Comprehensive Shoulder and Movement Assessment

Your physical therapist evaluates the strength balance between your internal and external rotators, assesses scapular movement patterns, and reviews your posture and sport mechanics to identify exactly why impingement is occurring.

Manual Therapy

Hands-on joint mobilization restores shoulder range of motion restricted by joint stiffness or capsular tightness. Soft tissue work reduces tightness in the pectoral muscles and posterior shoulder capsule that contribute to poor joint positioning during overhead motion.

Rotator Cuff and Scapular Strengthening

A targeted exercise program rebuilds external rotator and scapular stabilizer strength, restoring the muscle balance that keeps the shoulder in proper alignment during overhead activity. The program progresses gradually to avoid re-aggravating tendons before they have recovered full capacity.

Posture Correction

Swimmers and overhead athletes commonly develop a rounded, forward shoulder posture that perpetuates impingement even outside of the pool or gym. Your physical therapist addresses thoracic spine mobility and scapular positioning as part of the overall rehabilitation plan.

Return-to-Swimming or Return-to-Sport Program

A phased, progressive return plan is tailored to your specific sport and activity level. For swimmers, this includes stroke modification guidance and a safe yardage progression schedule. Clear milestones are set so you know exactly when you are ready to return to full intensity.

Patient Education

Your physical therapist provides guidance on warm-up routines, training load management, and shoulder maintenance exercises to carry into your regular routine long after treatment ends.

When Should You See a Physical Therapist for Shoulder Pain?

• Shoulder pain persisting for more than one to two weeks despite rest
• Pain that wakes you at night or prevents you from sleeping on the affected side
• Arm weakness noticeable during swimming, pressing, or lifting daily objects
• Shoulder pain that returns every time you swim or do overhead exercise
• A clicking, catching, or grinding sensation in the shoulder during movement
• Pain that gets progressively worse over the summer rather than settling between sessions
• Any change in your stroke mechanics or workout form due to discomfort

Early treatment is significantly faster, more effective, and less costly than waiting until the condition becomes chronic. You do not need a physician referral to book directly.

Get Back in the Water, Pain-Free

Swimmer’s shoulder responds extremely well to physical therapy, particularly when treatment begins before the condition becomes chronic. There is no reason to spend the rest of the summer sitting out of the pool or avoiding the workouts you enjoy.

At Physical Therapy of SA, our licensed physical therapists at our Live Oak, TX clinic specialize in treating shoulder pain for swimmers, athletes, and active adults across the San Antonio area. We create personalized treatment plans built around your sport, your goals, and your schedule.

Call us at 210-714-0812 or book your appointment online today. Same-week appointments are available.