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0363-5465/102/3030-0136$02.00/0 THE AMERICAN JOURNAL OF SPORTS MEDICINE, Vol. 30, No. 1 2002 American Orthopaedic Society for Sports Medicine
Current Concepts Current Concepts in the Rehabilitation of the Overhead Throwing AthleteKevin E. Wilk,* PT, Keith Meister, MD, and James R. Andrews, MD From *HealthSouth Rehabilitation Corporation and American Sports Medicine Institute, Birmingham, Alabama, Tampa Bay Devil Rays Baseball Team, Tampa Bay, Florida, Department of Orthopaedics, Division of Sports Medicine, University of Florida, Gainesville, Florida, and Alabama Sports Medicine and Orthopaedic Center, Birmingham, AlabamaABSTRACTThe overhead throwing motion is an extremely skillful and intricate movement that is very stressful on the shoulder joint complex. The overhead throwing athlete places extraordinary demands on this complex. Excessively high stresses are applied to the shoulder joint because of the tremendous forces generated by the thrower. The throwers shoulder must be lax enough to allow excessive external rotation, but stable enough to prevent symptomatic humeral head subluxations, thus requiring a delicate balance between mobility and functional stability. We refer to this as the throwers paradox. This balance is frequently compromised, which leads to injury. Numerous types of injuries may occur to the surrounding tissues during overhead throwing. Frequently, injuries can be successfully treated with a well-structured and carefully implemented nonoperative rehabilitation program. The key to successful nonoperative treatment is a thorough clinical examination and accurate diagnosis. Athletes often exhibit numerous adaptive changes that develop from the repetitive microtraumatic stresses observed during overhead throwing. Treatment should focus on the restoration of these adaptations during the rehabilitation program. In this article, the typical musculoskeletal profile of the overhead thrower and various rehabilitation programs for specific injuries are discussed. Rehabilitation follows a structured, multiphase approach with emphasis on controlling inflammation, restoring muscle balance, improving soft tissue flexibility, enhancing proprioception and neuromuscular control, and efficiently returning the athlete to competitive throwing.The repetitive microtraumatic stresses placed on the athletes shoulder joint complex during the throwing motion challenge the physiologic limits of the surrounding tissues. Frequently, alterations in throwing mechanics, muscle fatigue, muscle weakness or imbalance, and excessive capsular laxity may lead to tissue breakdown and injury. These injuries frequently involve the glenohumeral capsule, glenoid labrum, and the rotator cuff musculature. It has been our experience that most injuries to the throwers shoulder can be effectively treated with a proper nonoperative rehabilitation program. Generally, the rehabilitation program consists of activity modification, flexibility exercises, strengthening exercises, and a gradual return to throwing activities. In part one of his Current Concepts series, Meister 64 described a four-group classification system to categorize shoulder injuries in the overhead throwing athlete. We will discuss the rehabilitation program for each of the classifications. Bison and Andrews10 have also offered a classification system for injuries to the throwers shoulder. Each of these abnormalities develops because of unique etiologic factors. On the basis of these etiologic factors and the clinical examination, a proper rehabilitation program can be developed for each category. The key to effective treatment is a thorough clinical examination and appropriate differential diagnosis. In this article, we will discuss a typical nonoperative rehabilitation program for various shoulder injuries that have been discussed in the previous two articles.
Address correspondence and reprint requests to Kevin E. Wilk, PT, HealthSouth Rehabilitation Corporation, 1201 11th Avenue South, Suite 100, Birmingham, AL 35202. No author or related institution has received financial benefit from research in this study.
REHABILITATION OVERVIEWBefore the specifics of the rehabilitation program can be discussed, a thorough understanding of the clinical exam136
Vol. 30, No. 1, 2002
Rehabilitation of the Overhead Throwing Athlete
ination of the shoulder joint complex must be established. The evaluation of the throwers shoulder has been discussed in part two of the series by Meister.63 The physician must evaluate the thrower to establish a differential diagnosis, then the physical therapist or athlete trainer must evaluate the thrower to establish a list of physical limitations or problems that may be contributing to or resulting from the disorder. The rehabilitation specialist must evaluate range of motion, muscle strength, laxity, and proprioception. In addition, the rehabilitation specialist should address the athletes throwing program, exercise schedule, and throwing mechanics. Once these areas have been assessed, a comprehensive rehabilitation program can be established. Furthermore, during the evaluation process, the clinician must have an understanding of what is considered to be the normal or acceptable physiologic characteristics for the overhead throwing population. The purpose of the following sections is to convey to the reader the typical physical characteristics of the overhead throwing athlete. Specific range of motion, strength, laxity, and proprioceptive characteristics exhibited in throwing athletes will be discussed. The clinician must possess a complete understanding of what is typical for this unique athletic population so that abnormalities or differences can be appropriately identified and addressed. Range of Motion Most throwers exhibit an obvious motion disparity whereby external rotation is excessive and internal rotation is limited at 90 of abduction.8, 15, 47, 92 Several investigators have documented that pitchers exhibit greater external rotation of the shoulder than do position players.8, 47, 93 Brown et al.15 reported that professional pitchers exhibited 141 15 of shoulder external rotation measured at 90 of abduction. This was approximately 9 more than the nonthrowing shoulder, and approximately 9 more than the throwing shoulder of position players measured in 90 of abduction. Recently, Bigliani et al.8 examined the range of motion of 148 professional players. The investigators reported that the pitchers external rotation at 90 of abduction averaged 118 (range, 95 to 145) in the dominant shoulder, whereas the position players dominant shoulder averaged 108 (range, 80 to 105). In an ongoing study of professional baseball players, Wilk and Arrigo (unpublished data, 2000) assessed the range of shoulder motion of 372 professional baseball players. We have noted that pitchers exhibit an average of 129.9 10 of external rotation and 62.6 9 of internal rotation when passively assessed at 90 of abduction. In pitchers, the external rotation is approximately 7 greater in the throwing shoulder when compared with the nonthrowing shoulder, while internal rotation is 7 greater in the nonthrowing shoulder. In addition, the total motion (external rotation and internal rotation added together) in the throwing shoulder is equal (within 5) when compared with the nonthrowing shoulder. This was consistent in all 372 baseball players. We refer to this as the total motion concept (Fig. 1). We have also noted that pitchers exhibit
Fig. 1. The total motion concept: ER IR ER, external rotation; IR, internal rotation.
the greatest total arc of motion; that is, external and internal rotation at 90 of abduction, followed closely by catchers, then outfielders, and finally infielders. Furthermore, when comparing left-handed with right-handed pitchers, the left-handed throwers exhibit approximately 7 more external rotation and 12 more total motion when compared with right-handed throwers. These findings were statistically significant (P 0.01). Laxity Most throwers exhibit significant laxity of the glenohumeral joint, which permits excessive range of motion. The hypermobility of the throwers shoulder has been referred to as throwers laxity. 92 The laxity of the anterior and inferior glenohumeral joint capsule may be appreciated by the clinician during the stability assessment of the overhead throwers shoulder joint. Some clinicians have reported that the excessive laxity exhibited by the thrower is the result of repetitive throwing and they have referred to this as acquired laxity (J. R. Andrews, unpublished data, 1996), while others have documented that the overhead thrower exhibits congenital laxity.8 Bigliani et al.8 examined laxity in 72 professional baseball pitchers and 76 position players. The investigators noted a high degree of inferior glenohumeral joint laxity, with 61% of pitchers and 47% of position players exhibiting a positive sulcus sign in the throwing shoulder. Additionally, in the players who also exhibited a positive sulcus sign in the dominant shoulder, 89% of the pitchers and 100% of the position players exhibited a positive sulcus sign in the nondominant shoulder. Thus, it would appear that some baseball players exhibit inherent or congenital laxity, with superimposed acquired laxity, as a result of adaptive changes from throwing.
Wilk et al. TABLE 1 Glenohumeral Muscular Strength Values (in percent) in Professional Baseball Playersa180 deg/s 300 deg/s 450 deg/s
American Journal of Sports Medicine
Bilateral comparisons External rotation Internal rotation Abduction Adduction Unilateral muscle ratios External/internal rotation Abduction/adduction External rotation/abduction Isokinetic torque/body weight ratios External rotation Internal rotation Abduction Adductiona
95109 105120 100110 120135 6370 8287 6469