How to Minimize Training Flaws and Other Risks Casey J. O’Donnell, DO; Jay Bowen, DO; Jeffrey Fossati, MD THE PHYSICIAN AND SPORTSMEDICINE – VOL 33 – NO. 9 – SEPTEMBER 2005 For CME accreditation information, instructions and learning objectives, click here. In Brief: Shoulder pain resulting from glenohumeral instability is common among competitive swimmers. The biomechanics inherent to swimming promote muscular imbalances that stress the capsuloligamentous structures and contribute to shoulder instability. Most swimmers respond favorably to conservative treatment of rest and rehabilitation, while a small percentage may ultimately require surgical intervention. Swimmers who respond well to rehabilitation have a better prognosis for a successful return to swimming than those who require surgery. Overall, education in proper stroke and training techniques can minimize the likelihood that a competitive swimmer will experience disabling shoulder pain. Swimming is a rigorous sport that has been included in the modern Olympics since 1896.20 Because of its popularity, it is common for children to start competitive swimming at 5 or 6 years of age. In a typical 2-hour pool session, an elite-level competitive swimmer may swim between 6,000 and 7,000 yd, or about 3.5 to 4 miles. This amounts to swimming an average of 20 to 40 miles per week, which is the aerobic equivalent of running 80 to 160 miles.2 This high yardage means that competitive swimmers perform between 1,500 and 4,000 stroke cycles per day, or about 1,000,000 stroke cycles per year.3,4 Since female swimmers, on average, have shorter arm strokes, they may perform an additional 660,000 stroke cycles per year.3,5 Thus, it should be no surprise that shoulder pain is one of the leading ailments among competitive swimmers. The causes of shoulder pain are multifactorial and include the athlete’s sex, swimming experience, training distance, stroke choice, workout intensity, upper extremity weight training, stretching (especially when done with a partner), and use of hand paddles.4,6,7 A survey by McMaster et al8 demonstrated that 35% of senior national and Olympic swimmers experienced shoulder pain that prevented them from training effectively. Since Neer and Welsh9 coined the term “swimmer’s shoulder” in 1977, many researchers have sought to elicit the cause of shoulder pain in swimmers. The current understanding is that swimming selectively strengthens the anterior chest musculature and internal rotators of the shoulder, and, when combined with repetitive microtrauma to the shoulder, fosters an imbalance in the dynamic stability of the joint.2,10 Studies11-13 have found that this abnormal internal-to-external rotator torque ratio is an unavoidable consequence of swimming and is present even at the high school level. It is therefore prudent to adjust training programs accordingly, especially for beginning swimmers, to minimize the risk of future injury. The terms laxity and instability are commonly used when referring to joint pathology, and there is a significant difference between the two definitions. Laxity refers to the normal, painless freedom of movement around a joint, while instability refers to the pathologic tendency of a joint to subluxate or dislocate, resulting in pain or functional impairment.14,15 Asymptomatic, increased range of motion (ROM), or laxity, of the shoulder can be found in a large portion of swimmers, especially those at the highly competitive level. Significant controversy surrounds whether swimmers acquire shoulder laxity as a result of repetitive motion, or whether swimmers with inherent shoulder laxity are more efficient in the water, which leads them to stay in the sport longer and compete at a higher level.8,11,16 Regardless of its origin, glenohumeral laxity is facilitated by the repetitive overuse and muscular imbalances associated with swimming. This laxity may lead to glenohumeral instability and secondary impingement, causing shoulder pain. Stretching: Help or Hindrance? Similar to athletes in other competitive sports, most swimmers conduct a stretching routine prior to exercise. Unfortunately, stretching may be more harmful than helpful. For example, most of the stretches that swimmers perform (figure 1), including buddy stretches (figure 2), serve to stretch the anterior capsule of the shoulder. If the capsule is overstretched, the risk of instability and subsequent injury permanently increases.10 Therefore, the indication for stretching in swimming is limited. Any stretching should be specific to the individual and designed to correct specific muscular or capsular tightness.16 Because swimmers tend to have a relatively tight posterior capsule, which can promote impingement pain, swimmers without pain should focus on stretching the posterior capsule and anterior chest musculature.7 To selectively stretch the posterior capsule without stretching the scapular stabilizer muscles, it is necessary to stabilize the scapula. The easiest way to do this is to stretch the shoulder while lying supine, partially rolled onto the lateral border of the scapula. In swimmers who have kyphotic posture because of tight anterior chest and shoulder musculature, stretching those muscles without stretching the anterior capsule helps decrease the forward shoulder posture and increase the subacromial space.7 Swimmers with shoulder pain should be instructed to cease all anterior capsule stretching and instead focus on posterior capsule stretching.5,11 Swimmers with multidirectional instability or a history of subluxation should avoid all stretching.2 Buddy stretching should be avoided altogether, because it can easily range a shoulder beyond its physiologic barrier and promote further anatomic damage.10 For athletes in whom stretching is contraindicated, a gentle warm-up is sufficient to increase blood flow to the muscles and prepare them for the workout.10,17 A Role for Weight Training Most swimmers incorporate either weight lifting or dry land exercises into their training routine. Before embarking on a high-volume training program, all young swimmers, especially those with a previous injury, should be screened for glenohumeral joint laxity (table 1) and be instructed in a shoulder conditioning program. Care should be taken when performing exercises that require shoulder abduction and external rotation, such as lat pull-downs and the military press, which may cause apprehension and possible subluxation of the unstable shoulder. Bascharon et al18 demonstrated that a weight lifting circuit performed three times a week can successfully decrease shoulder pain in swimmers, both with and without a history of injury. TABLE 1. Tests to Identify Shoulder Pathologies in Competitive Swimmers Pathology Test Test Description Anterior instability Anterior apprehension With the patient supine, the shoulder is abducted to 90° and externally rotated. The test is positive if the patient becomes apprehensive about the shoulder subluxating or dislocating. Relocation maneuver During the apprehension test, the examiner applies a posterior force at (Fowler test, Jobethe glenohumeral joint through the abducted and externally rotated relocation test)shoulder. The maneuver is positive if the apprehension is relieved. Posterior instability Posterior apprehension With the patient supine or seated, an axial load is applied through the elbow to the adducted and internally rotated arm. The test is positive if the maneuver produces pain or apprehension. Inferior instability Sulcus sign With the patient standing, the examiner grasps the forearm and pulls inferiorly. The test is positive if a gap appears between the acromion and the humeral head. Impingement Neer’s impingement The patient’s arm is internally rotated and flexed at the shoulder in the plane of the scapula. Subacromial pain indicates a positive test. Hawkins-Kennedy impingement The patient’s shoulder is flexed to 90°, then internally rotated. Subacromial pain indicates a positive test. Source: Magee DJ: Orthopedic Physical Assessment, ed 4. Philadelphia, Saunders, 2002, pp 247-264. Dry land exercises should emphasize the scapular retractors (figure 3), lower trapezius, glenohumeral external rotators (figure 4), and “core” muscles, such as the abdominals and lower back, to prevent a strength imbalance between the internal and external rotators of the shoulder.2,8,11,19 Multiple types of training should be incorporated into the dry land or weight lifting programs. A combination of concentric, eccentric, force coupled, endurance, and speed training exercises better emphasizes the typical motions of a competitive swimming session, rather than one technique alone.20 Analyze Stroke Mechanics The best way to prevent swimming injuries is to use proper stroke technique. Poor body mechanics resulting from fatigue or improper stroke technique will lead to more drag on the swimmer, causing additional stress on the shoulder. However, ensuring proper body mechanics can be a challenge. Many amateur-level coaches have little or no training in how stroke technique, or changes in technique, relieve or worsen overuse injuries.2 The most popular ways to analyze stroke technique include the use of underwater windows, videotaping, and swimming in a flume. Since most practice time is spent swimming freestyle, it is the focus of this article. Information about the other three competitive strokes (ie, butterfly, backstroke, breastroke) is included in a review by Jones2 about specific stroke changes observed in each of the four competitive strokes during fatigue and injury. Each phase of the stroke cycle in freestyle presents an injury risk to the shoulder. During the pull phase, crossing the midline with the hand underwater or maintaining a “flat” body position (not rolling side to side properly) promotes shoulder impingement (figure 5). Swimmers who breathe consistently to one side stress the ipsilateral shoulder and should be encouraged to breathe bilaterally. Activities such as kicking with a kickboard or performing dips or the bench press may also foster shoulder laxity, leading to secondary impingement.7 Modifications to minimize shoulder pain include increasing the body roll, maintaining a high elbow, and avoiding excessive elbow extension during recovery (figure 6).8 Increasing the body roll reduces the amount of scapular protraction needed to maintain proper alignment of the glenohumeral joint, and thus lessens the demand on the serratus anterior and the other scapular muscles.11 Pink and Tibone10 explain some of the subtle modifications that swimmers may use to compensate for a painful shoulder during the freestyle stroke. The first sign of a potential injury is the “dropped” elbow during recovery (see figure 6). By dropping the elbow, a swimmer decreases the amount of internal rotation needed to clear the hand over the water, thus avoiding painful subacromial impingement. The dropped elbow also allows for a wider hand entry, which does not require as much scapular upward rotation or retraction, and therefore not as much humeral forward flexion. Over time, a wider entry may lead to an asymmetric pull, as evidenced by difficulty swimming straight. An asymmetric pull is usually compensated for by decreasing the force at the noninjured arm or changing the beat of the kick, which varies between individuals and degree of fatigue. Therefore, it is prudent that a swimmer who demonstrates a consistently dropped elbow be pulled from the workout and examined for signs of muscle fatigue, impingement, and joint instability. During training, it is common for swimmers to use hand paddles to increase strength and water perception. Unfortunately, hand paddles increase the amount of stress placed on the swimmer’s shoulder and they should be avoided, especially during periods of shoulder pain.5 Rehabilitation Steps When a swimmer becomes injured to the point where he or she cannot complete a normal practice session, he or she commonly undergoes rehabilitation apart from the team. This may not be the best approach. From a psychological standpoint, it may be better for a swimmer to keep training with the team rather than be isolated during complete rest or outside therapies.2 Modified rest and practice sets, such as kicking without a kickboard or performing dry land shoulder rehabilitation exercises on deck during team practices, can help the swimmer still feel like part of the team. Because muscular endurance will promote better glenohumeral stability during repetitive practice sessions, it is recommended that once the swimmer has obtained pain-free ROM, strengthening exercises be quantified by duration (eg, 5 minutes) rather than number of repetitions.7 This can help minimize dynamic glenohumeral instability resulting from muscular fatigue.8 Pepe and Rodosky20 describe a comprehensive treatment program for swimmers with shoulder pain that is divided into three phases: acute, recovery, and functional. Acute phase tasks consist primarily of rest and activity modification, which includes avoiding overhead activities, especially in the impingement zone above 90° of abduction. A stretching program should initially be performed passively or actively assisted, with the athlete avoiding mobilization techniques that stretch the anterior capsule. For the acutely inflamed shoulder, they recommend glenohumeral internal rotation and horizontal adduction while in the supine position (to maintain fixation of the scapula); adduction stretching with the hand behind the head (to emphasize the posterior-inferior capsule); and adduction stretching in the backscratching position (to emphasize the posterior-superior capsule). Recovery phase goals are to achieve normal active and passive ROM, strength, muscular balance, and scapular control. High numbers of repetitions with light weights or low-resistance resistance bands are used initially to develop endurance and to avoid further damage to the rotator cuff. The priority of this phase is to restore the normal kinematics of the shoulder by normalizing ROM and returning the agonist and antagonist muscles to their proper strength ratios. Emphasis should be placed on obtaining pain-free forward flexion, adduction, and internal rotation, since this is the position that typically provokes shoulder pain in swimmers, while strengthening the scapular stabilizers and external rotators of the shoulder. Functional phase criteria are: shoulder ROM of at least 90% of full, pain-free, active ROM; rotator cuff strength graded as at least 4/5; and a normal functioning kinetic chain. The purpose of this phase is to resume sport-specific activities. The athlete may resume activity by using a swim bench, followed by slow laps in the pool, and gradually integrate into the prior workout routine. The swimmer should not be allowed to return to full training unless he or she can consistently maintain proper shoulder mechanics despite a fatiguing workout. Rotator Cuff Strengthening and Plyometrics Kibler21 also outlines a comprehensive rehabilitation program for swimmers with shoulder pain. The program is divided into eight phases: diagnosis, pain reduction, integration of the kinetic chain, scapular stabilization, achievement of 90° of abduction, closed-chain rehabilitation, plyometric exercises, and rotator cuff exercises. The progression is similar to Pepe and Rodosky’s approach, with a few differences. Kibler explains that, because rotator cuff muscles do not work in isolation and are part of an overall force couple relationship, they should be rehabilitated as a unit, rather than as individual muscles. In addition, he incorporates plyometric exercises, which involve an initial eccentric loading of the muscle. After this “pretensioning phase,” the muscle performs a rapid, concentric contraction to develop a large amount of momentum and force. A study by Swanik et al22 demonstrated that after 6 weeks of training, a group of swimmers performing plyometric exercises improved significantly more than the control group in five of six proprioceptive tests and in six of six kinesthetic tests. Both Kibler and Swanik et al explain that plyometric exercises fine-tune muscle activity patterns by fostering joint proprioception, and are therefore the most appropriate open-chain exercises for functional shoulder rehabilitation. In addition, they both caution that, because of the large amount of force generated during both the eccentric and concentric phases, plyometric exercises should not be initiated until complete healing has occurred and the swimmer has a full, pain-free, active ROM. When to Consider Surgery As with most other sports-related injuries, surgery for shoulder pain is considered a last resort, and pain itself should not be the only indication for surgical stabilization.23 Some possible indications for surgery include paresthesias (eg, “dead arm” syndrome), recurrent instability, or difficulty with activities of daily living.6 Furthermore, a surgical evaluation should only be sought if 3 to 6 months of conservative treatment have failed.5,6 The decision to perform surgery is not without consequences. It is important for swimmers to understand that surgery will most likely result in decreased ROM and may reduce their level of performance.11 In fact, the lengthy recovery time and inherent variability in successful outcomes may end a swimmer’s competitive career.2 Surgical procedures range from the open capsular shift first described by Neer and Foster24 to less invasive, modern arthroscopic techniques. Since each case is individual, it is unlikely that a single procedure will reliably result in shoulder stability for every patient. For example, an inferior capsular shift may be appropriate for a patient with multidirectional instability, while an anterior capsulolabral reconstruction would be indicated for anterior glenohumeral instability.15,25,26 While open reconstruction is still considered the gold standard for treatment of shoulder instability, the trend is toward less invasive arthroscopic surgical repairs.15 Newer techniques allow surgeons to identify and repair multiple coexisting pathologies relatively noninvasively, thus giving arthroscopic surgery an advantage over traditional open techniques.19,25 Although once promising for the treatment of shoulder instability, thermal shrinkage techniques have become less common due to the lack of basic science data and rigorous clinical evaluations.4,7 Andrews and Dugas27 conducted a review of papers comparing traditional arthroscopic surgical treatment with and without thermal-assisted capsular shrinkage (TACS). Patients who underwent TACS in addition to repair of their primary injury obtained the best return-to-play results at their previous level of competition, reinforcing that TACS alone is insufficient for treatment. D’Alessandro et al28 found that 41% of patients with multidirectional instability reported unsatisfactory outcomes after TACS, with 20% requiring a surgical revision secondary to persistent instability. Similarly, Miniaci and McBirnie29 found that TACS had a substantial failure rate for treatment of multidirectional instability. Furthermore, there is mounting concern about the strength and mechanical properties of capsular tissue after thermal shrinkage, and what effects this could have on subsequent open or arthroscopic capsulorrhaphy.4,30 Returning to Swimming About 95% of swimmers are able to return to their prior level of competition after intensive functional rehabilitation, while the remaining 5% may benefit from surgical intervention.5,26 Unfortunately, the longer the recovery period, the less likely a swimmer is to return to his or her previous level of competition. Due to the amount of cumulative training lost, few swimmers have returned successfully to the highest elite ranks after a prolonged absence, including those who have undergone surgery.4 However, to emphasize that each case is individual, Russ31 details a case study in which a swimmer missed 6 weeks of the season because of shoulder pain and subsequent rehabilitation, and then posted a lifetime best swim after returning. He suggests that perhaps too much emphasis is placed on total yardage and not enough on the quality of the yardage. By decreasing their overall yardage to minimize the risk of overuse injuries, swimmers may be able to spend a proportionately greater amount of yardage as “quality” time in the pool. To ensure that swimmers perform at their peak, prevention of injuries is paramount. Increased effort devoted to educating coaches on early injury prevention and recognition, along with collaboration among the coach, swimmer, physician, and physical therapist, are important measures to make this a possibility.5 Simple Steps Yield Big Benefits Shoulder pain is often experienced by competitive swimmers. The most common causes are related to repetitive overuse of the shoulder, leading to muscular imbalances and subsequent secondary impingement from glenohumeral joint instability. A large majority of swimmers diagnosed with glenohumeral joint instability can successfully return to the sport after adequate rehabilitation. Other swimmers may benefit from surgical stabilization, but they have a poorer prognosis for a successful return to a highly competitive level. Despite advances in rehabilitation and surgical techniques, the best “treatment” remains prevention. In order to accomplish this, coaches and swimmers need to become familiar with proper training techniques and be able to recognize the typical changes in stroke patterns associated with shoulder dysfunction. A small change in training habits now may lead to a large payoff in the future. References 1. McMaster WC: Swimming injuries: an overview. Sports Med 1996;22(5):332-336 2. Jones JH: Swimming overuse injuries. Phys Med Rehabil Clin North Am 1999;10(1):77-94 3. Bak K, Faunl P: Clinical findings in competitive swimmers with shoulder pain. Am J Sports Med 1997;25(2):254-260 4. McMaster WC: Shoulder injuries in competitive swimmers. Clin Sports Med 1999;18(2):349-359 5. Bak K: Nontraumatic glenohumeral instability and coracoacromial impingement in swimmers. Scand J Med Sci Sports 1996;6(3):132-144 6. Beasley L, Faryniarz DA, Hannafin JA: Multidirectional instability of the shoulder in the female athlete. Clin Sports Med 2000;19(2):331-349 7. Kenal KA, Knapp LD: Rehabilitation of injuries in competitive swimmers. Sports Med 1996;22(5):337-347 8. McMaster WC, Roberts A, Stoddard T: A correlation between shoulder laxity and interfering pain in competitive swimmers. Am J Sports Med 1998;26(1):83-86 9. Neer CS II, Welsh RP: The shoulder in sports. Orthop Clin North Am 1977;8(3):583- 591 10. Pink MM, Tibone JE: The painful shoulder in the swimming athlete. Orthop Clin North Am 2000;31(2):247-261 11. Weldon EJ III, Richardson AB: Upper extremity overuse injuries in swimming: a discussion of swimmer’s shoulder. Clin Sports Med 2001;20(3):423-438 12. Ramsi M, Swanik KA, Swanik C, et al: Shoulder-rotator strength of high school swimmers over the course of a competitive season. J Sport Rehabil 2004;13(1):9-18 13. Astrab J, Small E, Kerner MS: Muscle strength and flexibility in young elite swimmers. Med Sci Sports Exerc 2001;33(5 suppl 1):S342 14. Dirckx JH, ed: Stedman’s Concise Medical Dictionary for the Health Professions, ed 3. Baltimore, Williams & Wilkins, 1997, pp 446-446, 480 15. Nebelung W, Jaeger A, Weidemann E: Rationales of arthroscopic shoulder stabilization. Arch Orthop Trauma Surg 2002;122(8):472-487 16. Zemek MJ, Magee DJ: Comparison of glenohumeral joint laxity in elite and recreational swimmers. Clin J Sport Med 1996;6(1):40-47 17. Mohr KJ, Pink MM, Elsner C, et al: Electromyographic investigation of stretching: the effect of warm-up. Clin J Sport Med 1998;8(3):215-220 18. Bascharon RA, Smith TS, Meyer H, et al: The effect of weight training in the prevention of rotator cuff injuries in adolescent competitive swimmers. J Am Osteopath Assoc 1996;96(9):558 19. Antoniou J, Duckworth DT, Harryman DT II: Capsulolabral augmentation for the management of posteroinferior instability of the shoulder. J Bone Joint Surg Am 2000;82(9):1220-1230 20. Pepe MD, Rodosky MW: Nonoperative treatment of common shoulder injuries in athletes. Sports Med Arthroscopy Rev 2001;9(1):96-104 21. Kibler WB: Shoulder rehabilitation: principles and practice. Med Sci Sports Exerc 1998;30(4 suppl):S40-50 22. Swanik KA, Lephart SM, Swanik CB, et al: The effects of shoulder plyometric training on proprioception and selected muscle performance characteristics. J Shoulder Elbow Surg 2002;11(6):579-586 23. Tibone JE, Lee TQ, Csintalan RP, et al: Quantitative assessment of glenohumeral translation. Clin Orthop Relat Res 2002;Jul(400):93-97 24. Neer CS, Foster CR: Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: a preliminary report. J Bone Joint Surg Am 1980;62(6):897-908 25. Metcalf MH, Savoie FH III, Field LD: Arthroscopic stabilization in posterior or multidirectional instability of the shoulder. Instr Course Lect 2003;52:17-23 26. Jobe FW, Pink M: Classification and treatment of shoulder dysfunction in the overhead athlete. J Orthop Sports Phys Ther 1993;18(2):427-432 27. Andrews JR, Dugas JR: Diagnosis and treatment of shoulder injuries in the throwing athlete: the role of thermal-assisted capsular shrinkage. Instr Course Lect 2001;50:17-21 28. D’Alessandro DF, Bradley JP, Fleischli JE, et al: Prospective evaluation of thermal capsulorraphy for shoulder instability: indications and results, two- to five-year followup. Am J Sports Med 2004;32(1):21-33 29. Miniaci A, McBirnie J: Thermal capsular shrinkage for treatment of multidirectional instability of the shoulder. J Bone Joint Surg Am 2003;85(12):2283-2287 30. Brown GA, Tan JL, Kirkley A: The lax shoulder in females: issues, answers, but many more questions. Clin Orthop Relat Res 2000;372(Mar):110-122 31. Russ DW: In-season management of shoulder pain in a collegiate swimmer: a team approach. J Orthop Sports Phys Ther 1998;27(5):371-376 Dr O’Donnell is administrative chief resident and Dr Bowen and Dr Fossati are clinical assistant professors in the Department of Physical Medicine and Rehabilitation at the University of Medicine and Dentistry of New Jersey in Newark. Dr Bowen is coordinator of the sports medicine fellowship at Associates in Rehabilitation in Morristown, New Jersey. Dr Fossati is also in private practice at the Northern New Jersey Pain and Rehabilitation Center in Hackensack. Address correspondence to Casey J. O’Donnell, DO, Dept of Physical Medicine and Rehabilitation, University of Medicine and Dentistry of New Jersey, 30 Bergen St, ADMC 1, Room 101, Newark, NJ 07101; e-mail to email@example.com.