IJSPT
ORIGINAL RESEARCH
THE RELATIONSHIP BETWEEN GLENOHUMERAL JOINT TOTAL ROTATIONAL RANGE OF MOTION AND THE FUNCTIONAL MOVEMENT SCREEN™ SHOULDER MOBILITY TEST Peter A. Sprague, PT, DPT, OCS1 G. Monique Mokha, PhD, ATC, LAT, CSCS1 Dustin R. Gatens, MS, ATC, LAT1 Rudy Rodriguez, Jr. ATC, LAT1
ABSTRACT Purpose/Background: Side to side asymmetry in glenohumeral joint rotation correlates with injury risk in overhead athletes. The purpose of the current study was to identify the relationship between side-to-side asymmetries in glenohumeral joint total rotational range of motion and shoulder mobility test scores from the Functional Movement Screen™ in collegiate overhead athletes. The authors hypothesized that asymmetries of > 10⬚ in glenohumeral total rotation would not be associated with asymmetrical findings in the Functional Movement Screen™ (FMS) shoulder mobility test. Methods: Passive glenohumeral total rotational range of motion and the shoulder mobility test of the FMS were measured during pre-participation examinations in 121 NCAA male and female Division II collegiate overhead athletes from varied sports. Passive shoulder range of motion was measured in supine at 90⬚ of abduction, with the humerus in the scapular plane using two measurers and a bubble goniometer. A Pearson Chi-square analysis, p 10⬚. Athletes with asymmetries in rotation of > 10⬚ were not any more likely to have asymmetries identified in the shoulder mobility test (95% CI=.555-2.658, P=.627). Conclusions Glenohumeral joint range of motion is one of multiple contributors to performance on the FMS shoulder mobility test, and alone, did not appear to influence results. The FMS shoulder mobility test should not be used alone as a means of identifying clinically meaningful differences of shoulder mobility in the overhead athlete. Clinicians working with overhead athletes may consider using both assessments as a complete screening tool for injury prevention measures. Level of Evidence: Level 3 Key Words: functional movement asymmetry, Functional Movement ScreenTM, glenohumeral joint rotation, overhead athlete
1
Nova Southeastern University, Davie, FL, USA
No funding was received for this work. This research was approved by Nova Southeastern University’s Internal Review Board
CORRESPONDING AUTHOR Peter A. Sprague, PT, DPT, OCS Nova Southeastern University- College of Osteopathic Medicine Sports Medicine Department Osteopathic Principles and Practice Department Davie, FL E-mail: [email protected]
The International Journal of Sports Physical Therapy | Volume 9, Number 5 | October 2014 | Page 657
INTRODUCTION Upper extremity injuries in the overhead athlete are prevalent in competitive sports, accounting for approximately 20% of all injuries in NCAA athletes across sports and up to 45% of all injuries in baseball.1-3 Differences in dominant versus non-dominant glenohumeral (GH) joint rotation in overhead athletes have been identified in the literature.4-8 These side to side differences in glenohumeral joint total rotational range of motion (TRROM), or the total arc of external rotation plus internal rotation, have been linked to upper extremity injury.9-14 Burkhart and Morgan9 reported a significant loss of internal rotation in symptomatic throwing shoulders of 124 baseball pitchers with type II SLAP lesions confirmed by arthroscopy. Wilk et al14 found a 2.5 times greater likelihood of injury in professional baseball pitchers who had greater than a 5⬚ deficit in TRROM of the dominant versus non-dominant shoulder. Garrison et al12 showed that baseball players who suffered an ulnar collateral ligament tear exhibited significantly greater deficits in TRROM of the injured arm than matched controls of healthy baseball players.
to identify increased injury risk in professional athletes with findings of an asymmetrical movement pattern on individual tests performed within the screen.28 One of the seven functional movements examined in the FMS is the shoulder mobility test. This test requires the subject to simultaneously reach one hand behind the back (internally rotate) and the other hand behind the head (externally rotate), bringing the hands as close together as possible in the thoracic region. (Figure 1) This type of reaching test has been described as a tool that measures GH joint mobility through functional shoulder movements.31,32 It has been suggested that impaired movement within the test may be indicative of more than just GH joint range of motion limitations.33 An understanding of the multi-variate contributors to movement dysfunctions associated with this test will provide clinicians with information that may guide choices for effective and specific injury prevention interventions.
These differences in rotational motion of the GH joint have been attributed to changes in bony morphology of the humeral head and glenoid that occur during the participation in overhead sports through musculoskeletal development.15-21 At birth, humans demonstrate a large amount of humeral retroversion. Throughout normal development, the humerus slowly becomes less retroverted, approaching normal humeral version, with individuals’ demonstrating equal internal rotation and external rotation by the time the epiphyseal plates close.16 The repetitive torsional strains placed upon the humeral head by throwing during development have been implicated in keeping the humeral head in a more retroverted position.17,20 The retroverted position of the humerus influences the total arc of motion toward greater external rotation without changing the total amount of available motion.22 Recently, the use of screening tools has been recommended to examine active populations for deficiencies in fundamental movements in order to identify athletes who have a higher likelihood of incurring an athletic injury.23-30 The Functional Movement ScreenTM (FMS) is one such tool that has been shown
Figure 1. The FMS shoulder rotation test. Note the position of the fists, which determines the score on this FMS test.
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Relatively small differences (>5⬚) in dominant versus non-dominant GH rotational range of motion have been suggested to be clinically relevant and have been shown to result in a greater likelihood of injury.14,34 The shoulder mobility test in the FMS may not be sensitive enough to identify these smaller rotational differences. To the authors’ knowledge, results of the FMS shoulder mobility test have not been examined with regard to measurements of total rotational range of motion of the GH joint. Therefore, the purpose of this study was to determine if the presence of an asymmetry of more than 10⬚ in TRROM could predict an asymmetry in the FMS shoulder mobility test in a group of intercollegiate overhead athletes. The authors hypothesized that overhead athletes with a side to side GH TRROM asymmetry would not be any more likely to demonstrate an asymmetry in side to side FMS shoulder mobility test scores. METHODS This research was an observational cohort design. GH joint TRROM and the FMS shoulder mobility test were measured during pre-participation examinations in 114 NCAA Division II collegiate athletes. Athletes were tested from the sports of baseball (n=34), softball (n=17), volleyball (n=10), men’s swimming (n=23), women’s swimming (n=20), and women’s tennis (n=10). Overhead athletes were chosen for this study because of the well-documented side-to-side differences in GH joint rotational ROM commonly found in this population.4-10,22 All testing was performed as part of the pre-participation examination process and all tests were performed on the same day for all sports. Bilateral passive TRROM measures were performed on all subjects using a two-measurer method and a bubble goniometer. (Figure 2) The left shoulders were always measured first out of convenience. The two measurer method with scapular stabilization, described by Wilk et al35 to have the best reliability among several measurement methods of GH rotation, was used for measuring internal rotation.36 Passive internal and external rotation were measured on each arm in order to identify the total arc of rotational range of motion of the GH joint. Measurements were taken with the shoulder in 90⬚ of abduction and in the plane of the glenoid using a bubble goniometer. Examiner one (PS) palpated the coracoid process
Figure 2. Two-measurer method of measuring passive glenohumeral internal rotation, using a bubble goniometer.
while passively moving the humerus to end range internal rotation. The measurement was taken by examiner two (RR) when movement of the coracoid first occurred and an endfeel was perceived, indicating the end of available passive glenohumeral joint motion and the beginning of scapular motion. External rotation was measured using palpation to detect movement of the scapula in order to identify the end of glenohumeral external rotation passive range of motion.36,37 (Figure 3). All measurements of TRROM were performed by the same two examiners. Examiner one had 21 years of experience in orthopaedic physical therapy practice and extensive experience working with post-surgical throwers, using
Figure 2. Two-measurer method of measuring passive glenohumeral internal rotation, using a bubble goniometer.
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this method of measurement for range of motion examination and re-examination. Examiner two has five years of experience as a certified athletic trainer working with collegiate and professional athletes. FMS shoulder mobility test measures were taken prior to or following TRROM measures, with a random assignment of measurement order. FMS shoulder mobility test measures were taken by an athletic trainer certified in FMS testing. All measures for all subjects were taken without warm-up or following any physical activity that day. The FMS shoulder mobility test was performed as described by Cook.33 The subject’s hand length is measured from the joint line of the wrist to the tip of the third digit. The subject is then asked to reach one arm overhead and down their thoracic region while reaching the contralateral upper extremity behind and up their back, attempting to place their hands, closed in fists, as close together as possible. A distance between hands in this position less than the measured hand length is considered a score of “3”. A distance between one hand length and one and one-half hand lengths is considered a score of “2”, and a distance greater than one and one-half hand lengths is given a score of “1”. If pain is felt during the test, a score of zero is given. After performing the test, the subjects perform a clearing test designed to test for pain provocation. If pain is reported with the clearing test, a score of zero is also given. The side of the overhead hand is recorded as the reference side. Scores that are unequal between right and left represent an asymmetry in this test. Subjects were categorized as either symmetrical or asymmetrical on the shoulder mobility test based upon their scores. This study was approved by the Internal Review Board at Nova Southeastern University. STATISTICAL METHODS For each subject, the presence of an asymmetry or absence of an asymmetry on each of the variables was defined. For TRROM, a side-to-side difference of greater than 10⬚ was used to define the presence of an asymmetry. This threshold was chosen based upon previous results in the literature defining normal amounts of asymmetry in side to side TRROM in overhead athletes,4-7 the amounts of rotation associated with bony morphological changes in the overhead athlete,19,21 and measurement error associated with standard goniometry43 and use of a bubble level
on a goniometer.35 A Pearson Chi-square analysis, p 10⬚ (17.76⬚ + 5.27⬚). There were 23 athletes who had mean differences in glenohumeral joint TTROM (16.12⬚ + 5.13⬚) but no asymmetries in FMS shoulder mobility scores. These results are presented in Table 2. Results of the Pearson Chi-Square analysis showed that overhead throwing athletes with asymmetries in TTROM were not any more likely to have an asymmetry in FMS shoulder mobility test score, χ2 (1, N=114)=0.236, p>.05, (95% CI=.555-2.658, P=.627). Statistical results are presented in Table 3.
Table 1. Subjects by Sport, and age distribution Sport Baseball Swimming Soball Volleyball Tennis Age range (years)
Men Subjects (n=57) 34 23
18-21
Women Subjects (n=57) 20 17 10 10 18-21
Table 2. Descriptive statistics for glenohumeral TTROM and FMS shoulder mobility measures
FMS Shoulder mobility Asymmetry No Yes Total
Glenohumeral TTROM Total Asymmetry No Yes 46 23 69 28 17 45 74 40 114
Table 3. Association between asymmetries in glenohumeral TTROM and FMS shoulder mobility scores Variable Glenohumeral TTROM
Variable Range >100
N 45
5⬚ in overhead athletes be defined as pathologic glenohumeral internal rotation deficit, or p-GIRD.34 According to the current findings, these small differences are not detectable when using the FMS shoulder mobility test. Another consideration regarding the relationship of TRROM of the glenohumeral joint to injury is the amount of total motion available in the dominant arm. Wilk14 found that 78% of all injuries documented in their study exhibited a TRROM > 176⬚. They hypothesized that too much mobility of the glenohumeral joint may place excessive demands on the dynamic and static stabilizers of the glenohumeral and scapulothoracic joints. Accurate measurements of isolated GH joint mobility are required in order to identify athletes that fall outside of these specific thresholds.
The authors of the current study chose to use the cutoff of 10⬚ as the cutoff to identify asymmetries in TRROM based upon the results of previous studies in the literature. Ellenbecker et al5 found an 7-9⬚ side to side difference in TRROM in shoulders of elite junior tennis players. Reeser et al7 measured a difference of 11⬚ in 276 elite volleyball players. Hurd et al6 and Ellenbecker et al4 also noted a 5⬚ difference in GH joint TROM in high school and professional baseball players, respectively. Measurement of the osseus changes on ultrasound that contribute to the total arc of motion changes found in the GH joints of overhead athletes, conducted by Wyland et al21 found a side to side difference of 9.4⬚ when adding glenoid retroversion and humeral retrotorsion. Reagan et al19 radiographically measured differences in humeral retrotorsion and found differences of 10.6⬚ when comparing the dominant to non-dominant shoulders. Clinically, it has been suggested that greater than a 5⬚ difference in TRROM be identified as pathologic in overhead athletes.34 Therefore, TRROM asymmetry of 10⬚ or greater was chosen as the threshold to encompass a previously defined meaningful difference in TRROM asymmetry14 and allow for a degree of measurement error commensurate to findings in the literature.43
Like TRROM, asymmetries identified within the FMS have been correlated with an increased risk of injury in the athletic population.28 The FMS shoulder mobility test examines the ability to use the upper quarters in a combination of opposing internal and external rotational patterns. An asymmetry in this test has been identified as a movement dysfunction that could contribute to injury or be the result of injury.31-33 Objective assessment of functional movement in the athletic population has been gaining attention recently in the literature because it has shown to have predictive value for identifying individuals at risk for athletic injury.23-30 The current study investigated the relationship between GH joint TRROM and a functional shoulder mobility test within a movement screen that has demonstrated validity in injury prediction in athletic populations. The authors’ sought to investigate whether or not the FMS shoulder mobility test is an adequate screening test to identify clinically significant differences in TRROM, or p-GIRD.
The current findings showed that there was no statistically significant association between asymmetries in GH joint TRROM and the results of the shoulder mobility test (symmetry vs. asymmetry) of the FMS. In fact, out of 45 athletes that demonstrated an asymmetry in the FMS shoulder mobility test, only 17 also demonstrated an asymmetry of 10⬚ or greater in GH joint TRROM. 28 subjects did not demonstrate side-to-side differences in GH joint TRROM > 10⬚. This data shows that the FMS shoulder mobility test is not sensitive enough to identify side-to-side asymmetries of this magnitude. TRROM and the FMS shoulder mobility tests are two very different assessments of the shoulder girdle. Rather than assessing total rotation of one glenohumeral joint, the FMS shoulder mobility test compares external rotation of one shoulder complex (including the glenohumeral joint, scapula-thoracic joint, and thoracic spine) plus internal rotation of the contralateral shoulder in combination with other factors that contribute to the ability to perform this reach test.
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The findings of the current study suggest that additional impairments other than GH TRROM differences may contribute to asymmetry in the FMS shoulder mobility test. The purpose of a movement screen is to examine movement patterns that test multiple contributors to normal function such as joint mobility, dynamic stability, and balance. The FMS shoulder mobility test considers these multiple contributors to normal movement and allows for a quick screen of the region to identify potential impairments that may lead to musculoskeletal injury. The inability to perform the movement without limitation or with symmetry suggests an underlying impairment during a basic functional movement pattern. If the added demands of speed and repetition associated with athletic activity are applied, these impairments may contribute to the inability to properly move throughout the upper extremity kinetic chain in a complex pattern without compensatory means, exposing the region to injury risk. Musculoskeletal screening does not identify the specific impairments to the dysfunctional movement pattern, it only allows for an identification of a potential problem. Further examination can allow for the identification of impairments contributing to a basic movement dysfunction. Contributors to dysfunction during the FMS shoulder mobility test may include thoracic extension mobility limitations, scapular mobility or stability limitations, and GH joint stability or mobility impairments. If the thoracic spine lacks the ability to extend, then the behind back reach internal rotation pattern can be limited. Lack of scapular mobility from tissue extensibility dysfunctions can also contribute to a lack of normal shoulder girdle movement that has been associated with injury.,7,9,38 Rotator cuff insufficiency has been shown to alter glenohumeral joint translation during active movements which can contribute to mobility deficits.39-42 Identifying causes of asymmetry found during movement screening may assist in the correction of functional movement and aid in injury prevention measures. A limitation of this study can be found in the measurement error inherent with goniometry. Mullaney et al43 found that a 9⬚ change or greater is necessary to be sure a meaningful change in GH joint rotation occurs when accounting for goniometry measurement error. The authors attempted to address that concern by using a 10⬚ threshold of side-to-side
differences to determine the presence of an asymmetry. However, this concern may not have been totally addressed by using the 10⬚ threshold, as the level of agreement used to calculate this meaningful change threshold in the Mullaney study was for either internal or external rotation, not total rotation measures. The TRROM was calculated by adding the two separate measurements. The use of a level on the goniometer and a two-measurer methodology was chosen to limit measurement error inherently associated with goniometry. Though Wilk et al35 were able to demonstrate that the method used in the current study for goniometric measures of internal rotation had a higher reliability when compared to other methods, the reliability of this technique is still only fair (intraclass correlation reported at 0.62). Reliability of the TRROM measurement method was not a part of the current study, which may be a limitation. CONCLUSION The FMS shoulder mobility test may provide information regarding scapular and thoracic mobility as well as contributors to glenohumeral mobility, however it is not related to passive TRROM measures of the glenohumeral joints in overhead athletes. Therefore, it is not likely to identify meaningful asymmetries in TRROM. Conversely, TRROM assessment does not consider any contributor to shoulder girdle movement other than glenohumeral joint ROM. Clinicians working with overhead athletes should consider using both assessments as a complete screening tool for injury prevention measures. REFERENCES 1. Conte S, Requa RK, Garrick JG. Disability days in major league baseball. Am J Sports Med.2001; 29(4):431–436. 2. Fleisig GS, Barrentine SM, Escamilla RF, et al. Kinetics of baseball pitching with implications about injury mechanisms.. Am J Sports Med.1995;23(2):421-437. 3. McFarland EG, Wasik M. Epidemiology of collegiate baseball injuries. Clin J Sport Med.1998;8(1):10–13. 4. Ellenbecker TS, Roetert EP, Bailie DS, et al. Glenohumeral joint total rotation range of motion in elite tennis players and baseball pitchers. Med Sci Sports Exerc.2002;34(12):2052-2056. 5. Ellenbecker TS, Roetert EP, Piorkowski PA, et al. Glenohumeral joint internal and external rotation range of motion in elite junior tennis players. J Orthop Sports Phys Ther. 1996;24(6):336-341.
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6. Hurd WJ, Kaplan KM, ElAttrache NS,et al. A profile of glenohumeral internal and external rotation motion in the uninjured high school baseball pitcher, part I: motion. J Athl Train. 2011;46(3):282-8. 7. Reeser JC, Joy EA, Poruczknik CA, et al.Risk factors for volleyball-related shoulder pain and dysfunction. PM R. 2010;2(1):27-36. 8. Torres RR, Gomes JL. Measurement of glenohumeral internal rotation in asymptomatic tennis players and swimmers. Am J Sports Med. 2009;37(5):1017–1023. 9. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology. Part I: pathoanatomy and biomechanics. Arthroscopy. 2003;19(4):404–420. 10. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology. Part II: evaluation and treatment of SLAP lesions in throwers. Arthroscopy.2003;19(5):531–539. 11. Dines JS, Frank JB, Akerman M, et al. Glenohumeral internal rotation deficits in baseball players with ulnar collateral ligament insufficiency. Am J Sports Med. 2009;37(3):566–570. 12. Garrison JC, Cole MA, Conway JE,et al. Shoulder range of motion deficits in baseball players with an ulnar collateral ligament tear. Am J Sports Med.2012;40(11):2597-603. 13. Myers JP, Laudner KG, Pasquale MR,et al. Glenohumeral range of motion deficits and posterior shoulder tightness in throwers with pathologic internal impingement. Am J Sports Med.2006;34(3):385-391. 14. Wilk KE, Macrina LC, Fleisig GS,et al. Correlation of glenohumeral internal rotation deficit and total rotational motion to shoulder injuries in professional baseball pitchers. Am J Sports Med. 2011;39(2):329– 335. 15. Crockett HG, Gross LB, Wilk KE, et al. Osseous adaptation and range of motion at the glenohumeral joint in professional baseball pitchers. Am J Sports Med.2002;30(1):20-26. 16. Edelson G. The development of humeral head retroversion. J Shoulder Elbow Surg. 2000;9(4):316318. 17. Meister K, Day T, Horodyski M,et al. Rotational motion changes in the glenohumeral joint of the adolescent/Little League baseball player. Am J Sports Med.2005;33(5):693-698.
rotation in the shoulder of college baseball players. Am J Sports Med. 2002;30(3):354-360. 20. Sabick MB, Kim YK, Torry MR,et al. Implications for the development of proximal humeral epiphysiolysis and humeral retrotorsion. Am J Sports Med.2005;33(11):1716-1722. 21. Wyland DJ, Pill SG, Shanley E,et al. Bony adaptation of the proximal humerus and glenoid correlate within the throwing shoulder of professional baseball pitchers. Am J Sports Med.2012;40(8):185862. 22. Wilk KE, Meister K, Andrews JR. Current concepts in the rehabilitation of the overhead throwing athlete. Am J Sports Med.2002;30(1):136–151. 23. Butler RJ, Contreras M, Burton LC,et al.Modifiable risk factors predict injuries in firefighters during training academies. Work.2013;46(1):11-7. 24. Butler RJ, Lehr ME, Fink ML,et al. Dynamic balance performance and noncontact lower extremity injury in college football players: an initial study. Sports Health. 2013 Sep;5(5):417-22. 25. Cook G, Burton L, Hoogenboom B, Voight M. Functional movement screening: the use of fundamental movements as an assessment of function part 1. Int J Sports Phys Ther. 2014;9(3):396–409. 26. Cook G, Burton L, Hoogenboom B, Voight M. Functional movement screening: the use of fundamental movements as an assessment of function part 2. Int J Sports Phys Ther. 2014;9(4):549–563. 27. Kiesel K, Plisky PJ, Voight ML. Can serious injury in professional football be predicted by a preseason functional movement screen? N Am J Sports Phys Ther. 2007;2(3): 147–158. 28. Kiesel KB, Butler RJ, Plisky PJ Limited and Asymmetrical Fundamental Movement Patterns Predict Injury in American Football Players. J Sport Rehabil. 2014;23(2):88-94. 29. Lisman P, O’Connor FG, Deuster PA, et al. Functional movement screen and aerobic fitness predict injuries in military training. Med Sci Sports Exerc. 2013;45(4):636-43. 30. Plisky PJ, Rauh MJ, Kaminski TW., et al. Star excursion balance test as a predictor of lower extremity injury in high school basketball players. J Orthop Sports Phys Ther. 2006;36(12):911-919. 31. Kendall F.P., McCreary EK, Prvance PG, et al. Muscles Testing and Function with Posture and Pain. 5th ed. Baltimore, MD: LippincottWilliams&Wilk; 2005.
18. Osbahr DC, Cannon DL, Speer KP. Retroversion of the humerus in the throwing shoulder of college baseball pitchers. Am J Sports Med.2002;30(3):347353.
32. Magee D. Orthopedic Physical Assessment. 5th ed. St. Louis, MI: Saunders Elsevier; 2008.
19. Reagan KM, Meister K, Horodyski MB,et al. Humeral retroversion and its relationship to glenohumeral
33. Cook, GE. Movement: Functional Movement Systems. Aptos, CA: On Target Publishing; 2010.
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34. Manske RC, Wilk KE, Davies GJ, Ellenbecker TE, Reinold M. Glenohumeral loss of motion: Friend or foe?. Int J Sports Phys Ther. 2013;8(5):537-551. 35. Wilk KE, Reinold MM, Macrina LC, et al. Glenohumeral internal rotation measurements differ depending on stabilization techniques. Sports Health. 2009;1(2):131-136. 36. Morrissey D, Morrissey MC, Driver W, et al. Manual landmark identification and tracking during the medial rotation test of the shoulder: an accuracy study using three-dimensional ultrasound and motion analysis measures. Man Ther. 2008;13(6):529535. 37. Norkin C, White DJ. Measurement of Joint Motion: A Guide to Goniometry. 2nd ed. Philadelphia, PA: Davis; 1995. 38. Laudner KG, Moline MT, Meister K. The relationship between forward scapular posture and posterior shoulder tightness among baseball players. Am J Sports Med. 2010 Oct;38(10):2106-12.
39. Byram IR, Bushnell BD, Dugger K, et al. Preseason shoulder strength measurements in professional baseball pitchers: identifying players at risk for injury. Am J Sports Med. 2010;38(7):1375-82. 40. Hwang E, Carpenter JE, Hughes RE,et al. Shoulder labral pathomechanics with rotator cuff tears. J Biomech. 2014;47(7):1733-8. 41. San Juan JG, Kosek P, Karduna AR. Humeral head translation after a suprascapular nerve block. J Appl Biomech. 2013;29(4):371-9. 42. Terrier A1, Reist A, Vogel A,et al. Effect of supraspinatus deficiency on humerus translation and glenohumeral contact force during abduction. Clin Biomech (Bristol, Avon). 2007;22(6):645-51. 43. Mullaney MJ, McHugh MP, Johnson CP,et al. Reliability of shoulder range of motion comparing a goniometer to a digital level. Physiother Theory Pract. 2010; 26(5):327-333.
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ORIGINAL RESEARCH
THE RELATIONSHIP BETWEEN GLENOHUMERAL JOINT TOTAL ROTATIONAL RANGE OF MOTION AND THE FUNCTIONAL MOVEMENT SCREEN™ SHOULDER MOBILITY TEST Peter A. Sprague, PT, DPT, OCS1 G. Monique Mokha, PhD, ATC, LAT, CSCS1 Dustin R. Gatens, MS, ATC, LAT1 Rudy Rodriguez, Jr. ATC, LAT1
ABSTRACT Purpose/Background: Side to side asymmetry in glenohumeral joint rotation correlates with injury risk in overhead athletes. The purpose of the current study was to identify the relationship between side-to-side asymmetries in glenohumeral joint total rotational range of motion and shoulder mobility test scores from the Functional Movement Screen™ in collegiate overhead athletes. The authors hypothesized that asymmetries of > 10⬚ in glenohumeral total rotation would not be associated with asymmetrical findings in the Functional Movement Screen™ (FMS) shoulder mobility test. Methods: Passive glenohumeral total rotational range of motion and the shoulder mobility test of the FMS were measured during pre-participation examinations in 121 NCAA male and female Division II collegiate overhead athletes from varied sports. Passive shoulder range of motion was measured in supine at 90⬚ of abduction, with the humerus in the scapular plane using two measurers and a bubble goniometer. A Pearson Chi-square analysis, p 10⬚. Athletes with asymmetries in rotation of > 10⬚ were not any more likely to have asymmetries identified in the shoulder mobility test (95% CI=.555-2.658, P=.627). Conclusions Glenohumeral joint range of motion is one of multiple contributors to performance on the FMS shoulder mobility test, and alone, did not appear to influence results. The FMS shoulder mobility test should not be used alone as a means of identifying clinically meaningful differences of shoulder mobility in the overhead athlete. Clinicians working with overhead athletes may consider using both assessments as a complete screening tool for injury prevention measures. Level of Evidence: Level 3 Key Words: functional movement asymmetry, Functional Movement ScreenTM, glenohumeral joint rotation, overhead athlete
1
Nova Southeastern University, Davie, FL, USA
No funding was received for this work. This research was approved by Nova Southeastern University’s Internal Review Board
CORRESPONDING AUTHOR Peter A. Sprague, PT, DPT, OCS Nova Southeastern University- College of Osteopathic Medicine Sports Medicine Department Osteopathic Principles and Practice Department Davie, FL E-mail: [email protected]
The International Journal of Sports Physical Therapy | Volume 9, Number 5 | October 2014 | Page 657
INTRODUCTION Upper extremity injuries in the overhead athlete are prevalent in competitive sports, accounting for approximately 20% of all injuries in NCAA athletes across sports and up to 45% of all injuries in baseball.1-3 Differences in dominant versus non-dominant glenohumeral (GH) joint rotation in overhead athletes have been identified in the literature.4-8 These side to side differences in glenohumeral joint total rotational range of motion (TRROM), or the total arc of external rotation plus internal rotation, have been linked to upper extremity injury.9-14 Burkhart and Morgan9 reported a significant loss of internal rotation in symptomatic throwing shoulders of 124 baseball pitchers with type II SLAP lesions confirmed by arthroscopy. Wilk et al14 found a 2.5 times greater likelihood of injury in professional baseball pitchers who had greater than a 5⬚ deficit in TRROM of the dominant versus non-dominant shoulder. Garrison et al12 showed that baseball players who suffered an ulnar collateral ligament tear exhibited significantly greater deficits in TRROM of the injured arm than matched controls of healthy baseball players.
to identify increased injury risk in professional athletes with findings of an asymmetrical movement pattern on individual tests performed within the screen.28 One of the seven functional movements examined in the FMS is the shoulder mobility test. This test requires the subject to simultaneously reach one hand behind the back (internally rotate) and the other hand behind the head (externally rotate), bringing the hands as close together as possible in the thoracic region. (Figure 1) This type of reaching test has been described as a tool that measures GH joint mobility through functional shoulder movements.31,32 It has been suggested that impaired movement within the test may be indicative of more than just GH joint range of motion limitations.33 An understanding of the multi-variate contributors to movement dysfunctions associated with this test will provide clinicians with information that may guide choices for effective and specific injury prevention interventions.
These differences in rotational motion of the GH joint have been attributed to changes in bony morphology of the humeral head and glenoid that occur during the participation in overhead sports through musculoskeletal development.15-21 At birth, humans demonstrate a large amount of humeral retroversion. Throughout normal development, the humerus slowly becomes less retroverted, approaching normal humeral version, with individuals’ demonstrating equal internal rotation and external rotation by the time the epiphyseal plates close.16 The repetitive torsional strains placed upon the humeral head by throwing during development have been implicated in keeping the humeral head in a more retroverted position.17,20 The retroverted position of the humerus influences the total arc of motion toward greater external rotation without changing the total amount of available motion.22 Recently, the use of screening tools has been recommended to examine active populations for deficiencies in fundamental movements in order to identify athletes who have a higher likelihood of incurring an athletic injury.23-30 The Functional Movement ScreenTM (FMS) is one such tool that has been shown
Figure 1. The FMS shoulder rotation test. Note the position of the fists, which determines the score on this FMS test.
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Relatively small differences (>5⬚) in dominant versus non-dominant GH rotational range of motion have been suggested to be clinically relevant and have been shown to result in a greater likelihood of injury.14,34 The shoulder mobility test in the FMS may not be sensitive enough to identify these smaller rotational differences. To the authors’ knowledge, results of the FMS shoulder mobility test have not been examined with regard to measurements of total rotational range of motion of the GH joint. Therefore, the purpose of this study was to determine if the presence of an asymmetry of more than 10⬚ in TRROM could predict an asymmetry in the FMS shoulder mobility test in a group of intercollegiate overhead athletes. The authors hypothesized that overhead athletes with a side to side GH TRROM asymmetry would not be any more likely to demonstrate an asymmetry in side to side FMS shoulder mobility test scores. METHODS This research was an observational cohort design. GH joint TRROM and the FMS shoulder mobility test were measured during pre-participation examinations in 114 NCAA Division II collegiate athletes. Athletes were tested from the sports of baseball (n=34), softball (n=17), volleyball (n=10), men’s swimming (n=23), women’s swimming (n=20), and women’s tennis (n=10). Overhead athletes were chosen for this study because of the well-documented side-to-side differences in GH joint rotational ROM commonly found in this population.4-10,22 All testing was performed as part of the pre-participation examination process and all tests were performed on the same day for all sports. Bilateral passive TRROM measures were performed on all subjects using a two-measurer method and a bubble goniometer. (Figure 2) The left shoulders were always measured first out of convenience. The two measurer method with scapular stabilization, described by Wilk et al35 to have the best reliability among several measurement methods of GH rotation, was used for measuring internal rotation.36 Passive internal and external rotation were measured on each arm in order to identify the total arc of rotational range of motion of the GH joint. Measurements were taken with the shoulder in 90⬚ of abduction and in the plane of the glenoid using a bubble goniometer. Examiner one (PS) palpated the coracoid process
Figure 2. Two-measurer method of measuring passive glenohumeral internal rotation, using a bubble goniometer.
while passively moving the humerus to end range internal rotation. The measurement was taken by examiner two (RR) when movement of the coracoid first occurred and an endfeel was perceived, indicating the end of available passive glenohumeral joint motion and the beginning of scapular motion. External rotation was measured using palpation to detect movement of the scapula in order to identify the end of glenohumeral external rotation passive range of motion.36,37 (Figure 3). All measurements of TRROM were performed by the same two examiners. Examiner one had 21 years of experience in orthopaedic physical therapy practice and extensive experience working with post-surgical throwers, using
Figure 2. Two-measurer method of measuring passive glenohumeral internal rotation, using a bubble goniometer.
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this method of measurement for range of motion examination and re-examination. Examiner two has five years of experience as a certified athletic trainer working with collegiate and professional athletes. FMS shoulder mobility test measures were taken prior to or following TRROM measures, with a random assignment of measurement order. FMS shoulder mobility test measures were taken by an athletic trainer certified in FMS testing. All measures for all subjects were taken without warm-up or following any physical activity that day. The FMS shoulder mobility test was performed as described by Cook.33 The subject’s hand length is measured from the joint line of the wrist to the tip of the third digit. The subject is then asked to reach one arm overhead and down their thoracic region while reaching the contralateral upper extremity behind and up their back, attempting to place their hands, closed in fists, as close together as possible. A distance between hands in this position less than the measured hand length is considered a score of “3”. A distance between one hand length and one and one-half hand lengths is considered a score of “2”, and a distance greater than one and one-half hand lengths is given a score of “1”. If pain is felt during the test, a score of zero is given. After performing the test, the subjects perform a clearing test designed to test for pain provocation. If pain is reported with the clearing test, a score of zero is also given. The side of the overhead hand is recorded as the reference side. Scores that are unequal between right and left represent an asymmetry in this test. Subjects were categorized as either symmetrical or asymmetrical on the shoulder mobility test based upon their scores. This study was approved by the Internal Review Board at Nova Southeastern University. STATISTICAL METHODS For each subject, the presence of an asymmetry or absence of an asymmetry on each of the variables was defined. For TRROM, a side-to-side difference of greater than 10⬚ was used to define the presence of an asymmetry. This threshold was chosen based upon previous results in the literature defining normal amounts of asymmetry in side to side TRROM in overhead athletes,4-7 the amounts of rotation associated with bony morphological changes in the overhead athlete,19,21 and measurement error associated with standard goniometry43 and use of a bubble level
on a goniometer.35 A Pearson Chi-square analysis, p 10⬚ (17.76⬚ + 5.27⬚). There were 23 athletes who had mean differences in glenohumeral joint TTROM (16.12⬚ + 5.13⬚) but no asymmetries in FMS shoulder mobility scores. These results are presented in Table 2. Results of the Pearson Chi-Square analysis showed that overhead throwing athletes with asymmetries in TTROM were not any more likely to have an asymmetry in FMS shoulder mobility test score, χ2 (1, N=114)=0.236, p>.05, (95% CI=.555-2.658, P=.627). Statistical results are presented in Table 3.
Table 1. Subjects by Sport, and age distribution Sport Baseball Swimming Soball Volleyball Tennis Age range (years)
Men Subjects (n=57) 34 23
18-21
Women Subjects (n=57) 20 17 10 10 18-21
Table 2. Descriptive statistics for glenohumeral TTROM and FMS shoulder mobility measures
FMS Shoulder mobility Asymmetry No Yes Total
Glenohumeral TTROM Total Asymmetry No Yes 46 23 69 28 17 45 74 40 114
Table 3. Association between asymmetries in glenohumeral TTROM and FMS shoulder mobility scores Variable Glenohumeral TTROM
Variable Range >100
N 45
5⬚ in overhead athletes be defined as pathologic glenohumeral internal rotation deficit, or p-GIRD.34 According to the current findings, these small differences are not detectable when using the FMS shoulder mobility test. Another consideration regarding the relationship of TRROM of the glenohumeral joint to injury is the amount of total motion available in the dominant arm. Wilk14 found that 78% of all injuries documented in their study exhibited a TRROM > 176⬚. They hypothesized that too much mobility of the glenohumeral joint may place excessive demands on the dynamic and static stabilizers of the glenohumeral and scapulothoracic joints. Accurate measurements of isolated GH joint mobility are required in order to identify athletes that fall outside of these specific thresholds.
The authors of the current study chose to use the cutoff of 10⬚ as the cutoff to identify asymmetries in TRROM based upon the results of previous studies in the literature. Ellenbecker et al5 found an 7-9⬚ side to side difference in TRROM in shoulders of elite junior tennis players. Reeser et al7 measured a difference of 11⬚ in 276 elite volleyball players. Hurd et al6 and Ellenbecker et al4 also noted a 5⬚ difference in GH joint TROM in high school and professional baseball players, respectively. Measurement of the osseus changes on ultrasound that contribute to the total arc of motion changes found in the GH joints of overhead athletes, conducted by Wyland et al21 found a side to side difference of 9.4⬚ when adding glenoid retroversion and humeral retrotorsion. Reagan et al19 radiographically measured differences in humeral retrotorsion and found differences of 10.6⬚ when comparing the dominant to non-dominant shoulders. Clinically, it has been suggested that greater than a 5⬚ difference in TRROM be identified as pathologic in overhead athletes.34 Therefore, TRROM asymmetry of 10⬚ or greater was chosen as the threshold to encompass a previously defined meaningful difference in TRROM asymmetry14 and allow for a degree of measurement error commensurate to findings in the literature.43
Like TRROM, asymmetries identified within the FMS have been correlated with an increased risk of injury in the athletic population.28 The FMS shoulder mobility test examines the ability to use the upper quarters in a combination of opposing internal and external rotational patterns. An asymmetry in this test has been identified as a movement dysfunction that could contribute to injury or be the result of injury.31-33 Objective assessment of functional movement in the athletic population has been gaining attention recently in the literature because it has shown to have predictive value for identifying individuals at risk for athletic injury.23-30 The current study investigated the relationship between GH joint TRROM and a functional shoulder mobility test within a movement screen that has demonstrated validity in injury prediction in athletic populations. The authors’ sought to investigate whether or not the FMS shoulder mobility test is an adequate screening test to identify clinically significant differences in TRROM, or p-GIRD.
The current findings showed that there was no statistically significant association between asymmetries in GH joint TRROM and the results of the shoulder mobility test (symmetry vs. asymmetry) of the FMS. In fact, out of 45 athletes that demonstrated an asymmetry in the FMS shoulder mobility test, only 17 also demonstrated an asymmetry of 10⬚ or greater in GH joint TRROM. 28 subjects did not demonstrate side-to-side differences in GH joint TRROM > 10⬚. This data shows that the FMS shoulder mobility test is not sensitive enough to identify side-to-side asymmetries of this magnitude. TRROM and the FMS shoulder mobility tests are two very different assessments of the shoulder girdle. Rather than assessing total rotation of one glenohumeral joint, the FMS shoulder mobility test compares external rotation of one shoulder complex (including the glenohumeral joint, scapula-thoracic joint, and thoracic spine) plus internal rotation of the contralateral shoulder in combination with other factors that contribute to the ability to perform this reach test.
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The findings of the current study suggest that additional impairments other than GH TRROM differences may contribute to asymmetry in the FMS shoulder mobility test. The purpose of a movement screen is to examine movement patterns that test multiple contributors to normal function such as joint mobility, dynamic stability, and balance. The FMS shoulder mobility test considers these multiple contributors to normal movement and allows for a quick screen of the region to identify potential impairments that may lead to musculoskeletal injury. The inability to perform the movement without limitation or with symmetry suggests an underlying impairment during a basic functional movement pattern. If the added demands of speed and repetition associated with athletic activity are applied, these impairments may contribute to the inability to properly move throughout the upper extremity kinetic chain in a complex pattern without compensatory means, exposing the region to injury risk. Musculoskeletal screening does not identify the specific impairments to the dysfunctional movement pattern, it only allows for an identification of a potential problem. Further examination can allow for the identification of impairments contributing to a basic movement dysfunction. Contributors to dysfunction during the FMS shoulder mobility test may include thoracic extension mobility limitations, scapular mobility or stability limitations, and GH joint stability or mobility impairments. If the thoracic spine lacks the ability to extend, then the behind back reach internal rotation pattern can be limited. Lack of scapular mobility from tissue extensibility dysfunctions can also contribute to a lack of normal shoulder girdle movement that has been associated with injury.,7,9,38 Rotator cuff insufficiency has been shown to alter glenohumeral joint translation during active movements which can contribute to mobility deficits.39-42 Identifying causes of asymmetry found during movement screening may assist in the correction of functional movement and aid in injury prevention measures. A limitation of this study can be found in the measurement error inherent with goniometry. Mullaney et al43 found that a 9⬚ change or greater is necessary to be sure a meaningful change in GH joint rotation occurs when accounting for goniometry measurement error. The authors attempted to address that concern by using a 10⬚ threshold of side-to-side
differences to determine the presence of an asymmetry. However, this concern may not have been totally addressed by using the 10⬚ threshold, as the level of agreement used to calculate this meaningful change threshold in the Mullaney study was for either internal or external rotation, not total rotation measures. The TRROM was calculated by adding the two separate measurements. The use of a level on the goniometer and a two-measurer methodology was chosen to limit measurement error inherently associated with goniometry. Though Wilk et al35 were able to demonstrate that the method used in the current study for goniometric measures of internal rotation had a higher reliability when compared to other methods, the reliability of this technique is still only fair (intraclass correlation reported at 0.62). Reliability of the TRROM measurement method was not a part of the current study, which may be a limitation. CONCLUSION The FMS shoulder mobility test may provide information regarding scapular and thoracic mobility as well as contributors to glenohumeral mobility, however it is not related to passive TRROM measures of the glenohumeral joints in overhead athletes. Therefore, it is not likely to identify meaningful asymmetries in TRROM. Conversely, TRROM assessment does not consider any contributor to shoulder girdle movement other than glenohumeral joint ROM. Clinicians working with overhead athletes should consider using both assessments as a complete screening tool for injury prevention measures. REFERENCES 1. Conte S, Requa RK, Garrick JG. Disability days in major league baseball. Am J Sports Med.2001; 29(4):431–436. 2. Fleisig GS, Barrentine SM, Escamilla RF, et al. Kinetics of baseball pitching with implications about injury mechanisms.. Am J Sports Med.1995;23(2):421-437. 3. McFarland EG, Wasik M. Epidemiology of collegiate baseball injuries. Clin J Sport Med.1998;8(1):10–13. 4. Ellenbecker TS, Roetert EP, Bailie DS, et al. Glenohumeral joint total rotation range of motion in elite tennis players and baseball pitchers. Med Sci Sports Exerc.2002;34(12):2052-2056. 5. Ellenbecker TS, Roetert EP, Piorkowski PA, et al. Glenohumeral joint internal and external rotation range of motion in elite junior tennis players. J Orthop Sports Phys Ther. 1996;24(6):336-341.
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6. Hurd WJ, Kaplan KM, ElAttrache NS,et al. A profile of glenohumeral internal and external rotation motion in the uninjured high school baseball pitcher, part I: motion. J Athl Train. 2011;46(3):282-8. 7. Reeser JC, Joy EA, Poruczknik CA, et al.Risk factors for volleyball-related shoulder pain and dysfunction. PM R. 2010;2(1):27-36. 8. Torres RR, Gomes JL. Measurement of glenohumeral internal rotation in asymptomatic tennis players and swimmers. Am J Sports Med. 2009;37(5):1017–1023. 9. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology. Part I: pathoanatomy and biomechanics. Arthroscopy. 2003;19(4):404–420. 10. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology. Part II: evaluation and treatment of SLAP lesions in throwers. Arthroscopy.2003;19(5):531–539. 11. Dines JS, Frank JB, Akerman M, et al. Glenohumeral internal rotation deficits in baseball players with ulnar collateral ligament insufficiency. Am J Sports Med. 2009;37(3):566–570. 12. Garrison JC, Cole MA, Conway JE,et al. Shoulder range of motion deficits in baseball players with an ulnar collateral ligament tear. Am J Sports Med.2012;40(11):2597-603. 13. Myers JP, Laudner KG, Pasquale MR,et al. Glenohumeral range of motion deficits and posterior shoulder tightness in throwers with pathologic internal impingement. Am J Sports Med.2006;34(3):385-391. 14. Wilk KE, Macrina LC, Fleisig GS,et al. Correlation of glenohumeral internal rotation deficit and total rotational motion to shoulder injuries in professional baseball pitchers. Am J Sports Med. 2011;39(2):329– 335. 15. Crockett HG, Gross LB, Wilk KE, et al. Osseous adaptation and range of motion at the glenohumeral joint in professional baseball pitchers. Am J Sports Med.2002;30(1):20-26. 16. Edelson G. The development of humeral head retroversion. J Shoulder Elbow Surg. 2000;9(4):316318. 17. Meister K, Day T, Horodyski M,et al. Rotational motion changes in the glenohumeral joint of the adolescent/Little League baseball player. Am J Sports Med.2005;33(5):693-698.
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34. Manske RC, Wilk KE, Davies GJ, Ellenbecker TE, Reinold M. Glenohumeral loss of motion: Friend or foe?. Int J Sports Phys Ther. 2013;8(5):537-551. 35. Wilk KE, Reinold MM, Macrina LC, et al. Glenohumeral internal rotation measurements differ depending on stabilization techniques. Sports Health. 2009;1(2):131-136. 36. Morrissey D, Morrissey MC, Driver W, et al. Manual landmark identification and tracking during the medial rotation test of the shoulder: an accuracy study using three-dimensional ultrasound and motion analysis measures. Man Ther. 2008;13(6):529535. 37. Norkin C, White DJ. Measurement of Joint Motion: A Guide to Goniometry. 2nd ed. Philadelphia, PA: Davis; 1995. 38. Laudner KG, Moline MT, Meister K. The relationship between forward scapular posture and posterior shoulder tightness among baseball players. Am J Sports Med. 2010 Oct;38(10):2106-12.
39. Byram IR, Bushnell BD, Dugger K, et al. Preseason shoulder strength measurements in professional baseball pitchers: identifying players at risk for injury. Am J Sports Med. 2010;38(7):1375-82. 40. Hwang E, Carpenter JE, Hughes RE,et al. Shoulder labral pathomechanics with rotator cuff tears. J Biomech. 2014;47(7):1733-8. 41. San Juan JG, Kosek P, Karduna AR. Humeral head translation after a suprascapular nerve block. J Appl Biomech. 2013;29(4):371-9. 42. Terrier A1, Reist A, Vogel A,et al. Effect of supraspinatus deficiency on humerus translation and glenohumeral contact force during abduction. Clin Biomech (Bristol, Avon). 2007;22(6):645-51. 43. Mullaney MJ, McHugh MP, Johnson CP,et al. Reliability of shoulder range of motion comparing a goniometer to a digital level. Physiother Theory Pract. 2010; 26(5):327-333.
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