Pattern overload describes injury to soft tissues from repetitive motion in one pattern of movement or restricted movement in one or more planes of motion. Pattern overload results primarily from faulty movement patterns and repetitive stress. Our bodies are composed of a series of structural kinetic chains, so that dysfunction or imbalance in one area can quickly lead to dysfunctions in other parts of the body. This can arise due to the body’s inability to properly load share across the joints.

Swimmer’s Shoulder

The term swimmer’s shoulder was first coined in 19781 to describe anterior shoulder pain occurring during and after workouts. Pain in the shoulder is common in swimmers. Since the shoulder is an inherently unstable but highly mobile joint, shoulder function is dependent on the coordinated function of many muscle groups. These include the rotator cuff muscles, those that control the scapula or shoulder blade, pectorals, latissimus dorsi and muscles in the upper and lower back, as well as abdominal and pelvic muscles. The repetitive overhead activity of the swimming stroke can tire these muscles. This in turn can lead to distinct changes in the function of the shoulder, resulting in the pain that is commonly known as swimmer’s shoulder.

As of 2007, there were 250,000 competitive swimmers in the United States, according to USA Swimming,2 the governing body. Competitive swimmers can average between 6000-10,000 meters (6,500-1,100 yds) per day and upward of 60,000-80,000 meters per week.3,4,5 With an average stroke count at 8 to 10 per 25m, swimmers perform 30,000 rotations of each shoulder per week, placing tremendous stress on the shoulder girdle and glenohumeral joint.6

With swimming, it is important to assess the mobility of the hips and thoracic, as well as the stability of the lumbar spine, cervical spine and shoulder girdle. Commonly, the hip flexors are tight and restrict hip extension needed during kicking. This can cause shear stress in the lower back and lead to lower back pain. The levator scapulae, a muscle that runs from the top of the shoulder blade and attaches to the back of the vertebrae of the upper neck, is often overworked because of head rotation during breathing. This is especially true for one-sided breathers. Tightness can pull the shoulder forward and lead to impingement of the rotator cuff.

Swimmers typically develop poor posture because of tight latissimus dorsi, pectorals and all internal shoulder rotators. They also have tight quadriceps and hip flexors, which can restrict hip mobility. These muscles are overused during swimming. Protracted shoulders disrupt the normal axis of rotation of the shoulder joint. The subscapularis (i.e., the rotator cuff muscle located in front of the shoulder blade) often becomes overworked, tightens and glues down with the serratus anterior and then becomes weak. This muscle is needed to create a force couple that stabilizes the ball and socket joint during swimming and overhead movements. Losing this force couple also results in shoulder impingement, known as swimmer’s shoulder.

Another common cause for anterior shoulder pain in swimmers is “glueddown adhesions” between the anterior and middle deltoid, infraspinatus and the long head of the biceps. When these tissues become glued down, there is a reduction of sliding of these structures during flexion, horizontal abduction and external rotation movements of the swimming stroke. As these tissues rub, they become inflamed and irritated. This very issue is often the cause of bicipital tendinitis.

Examination: Use of the Functional Movement Screen™ can provide key insight into faulty movement. Shoulder mobility and the overhead squat will reveal limitations of internal rotation of the shoulder, as well as poor thoracic and hip mobility. All examinations should include an assessment of at least these movements. In addition, evaluating horizontal abduction as well as adduction will uncover limited movements due to adhesions between the latissimus dorsi, triceps and teres minor, as well as posterior capsule of the glenohumeral joint. The Internal Rotation Resistance Test should be included, as well as palpation of the shoulder girdle and cervical spine musculature. This includes the subscapularis, serratus anterior, infraspinatus, teres major/minor, pectoralis major/minor, levator scapulae/rhomboid/ serratus posterior superior, deltoid, latissimus and triceps. Adhesions in these muscles are often found and must be treated first. Addressing joint dyskinesis with manipulation is key for the lower cervical, first rib and thoracic spine.

Internal Rotation Resistance Test: Warren Hammer, DC, has written about this test.7 The examiner stands behind the patient with the patient’s affected arm supported on the examiner’s knee held in glenohumeral abduction at 90 degrees and 90 degrees external rotation. The examiner then muscle tests the rotator cuff, testing infraspinatus and teres minor into external rotation and then the subscapularis into internal rotation. Good strength in ER compared with apparent weakness in IR constitutes a positive test. The weakness indicates probable non-outlet impingement, most commonly a SLAP lesion.

When testing internal rotation, the humeral head is vectored toward the glenoid rim and labrum. This places tension on the biceps labral complex and capsulolabral border so that pain from subtle subluxation and SLAP lesions will be magnified.

Weakness in ER is considered a negative test and could indicate primary impingement. (For more by Dr. Hammer, see April 2014 ACA News, p. 15)

Diagnostic Imaging

Most patients can be treated conservatively for four to six weeks without imaging, especially when many of the above-mentioned dysfunctions are present on examination. Failure to respond to treatment should be evaluated with an MRI or an MRA if labral tear/SLAP lesion is suspected.

Coaching Tips and Dealing With Injuries

Common mechanical faults in swimming that can lead to shoulder injury are:

1. Hand entry that crosses midline.

2. Thumb-down entry.

3. Asymmetric body roll.

4. Unilateral breathing.

5. Crossing midline during catch and pull.

The swim coach is essential to the success of optimal performance in the pool. An educated swim coach with significant video analysis experience can be extremely helpful by educating swimmers on how to reduce stress in the water and increase efficiency.

For proper function and optimal stroke mechanics, the right amount of mobility and stability is imperative. In some cases that means flexibility training for longer muscles or mobilization for better joint motion. All athletes need good mobility of their hips and thoracic spine. A strong and functioning core will stabilize the lower back and help the swimmer to be more streamlined in the water.

All athletes should focus on plank, side plank and gluteal bridging exercises to strengthen their cores. The main job of the core is to create midline stability, check flexion and extension movements and prevent rotation of the lumbar spine. A strong, well-activated core allows for a stiff lumbar spine that is protected from undue stress as the body transfers kinetic energy from the lower extremity through the thoracolumbar fascia and into the thoracic spine, scapulothoracic joints and upper extremity. A deconditioned core causes the athlete to lose power transfer from the lower to the upper body and often results in lower-back injuries.

A comprehensive exercise program should focus on restoring mobility to the hip and thoracic spine, flexibility to tight and overworked muscles and improving core and shoulder girdle stability. Once the body is moving properly, athletes then can work to improve strength, endurance, balance and focus on sport-specific drills to enhance performance. Releasing all the adhesions in the muscles of the shoulder prior to engaging in strengthening exercises is essential.

The Big Picture

A common thread in most sports-related injuries is overuse of muscles, accumulation of load from high volume training and repetitive strain injury. Active Release Techniques® provide a means to effectively and rapidly diagnose and treat these stressful repetitive strain injuries without surgical intervention and allow the patient to quickly return to sports.

Remember that once symptoms of injury have cleared, future prevention should begin by including regular foam roller self-massage and mobility exercises, as well as properly prescribed rehab exercise tracks to offer a progression from muscle activation to strengthening exercises.

Endnotes

1. Kennedy JC, Hawkins R, Krissoff WB. Orthopeaedic manifestations of swimming. Am J Sports Med. 1978;6:309-322.

2. Membership demographics for the 2007 membership year. USA Swimming. www.usaswimming.org.

3. Beach ML, Whitney SL, Dickoff-Hoffman SA. Relationship of shoulder flexibility, strength, and endurance to shoulder pain in competitive swimmers. J Orthop Sports Phys Ther. 1992;16(6):262-268.

4. Greipp JF. Swimmer’s shoulder: the influence of flexibility and weight training. Phys Sportsmed. 1985;13(8):92-105.

5. Richardson AB, Jobe FW, Collins HR. The shoulder in competitive swimming. Am J Sports Med. 1980;8(3):159-163.

6. Heinlein S, Cosgarea A. Biomechanical considerations in the competitive swimmer’s shoulder. Sports Health. Nov 2010; 2(6): 519–525.

7. Hammer W. New significant shoulder diagnostic test. Dynamic Chiropractic – May 7, 2001, Vol. 19, Issue 10.

Dr. Fontaine serves patients in Northern Virginia at his clinic, Potomac Chiropractic & Sports Medicine. He focuses on combining chiropractic, sports medicine and Active Release Techniques® (ART). He trained at the Texas Back Institute and is a full body certified ART provider. A former collegiate baseball player, he is a member of DC Tri Club and Trident CrossFit and has completed more than 30 triathlons. He is a volunteer emergency medical technician (EMT)/firefighter with Fairfax County Fire & Rescue. He is the creator of Prehab4Performance blog, an author and speaker.