Jenny McConnell, 1 Cyril Donnelly, 2 Samuel Hamner, 3 James Dunne, 2 Thor Besier 4

Transcription

1 Effect of Shoulder Taping on Maximum Shoulder External and Internal Rotation Range in Uninjured and Previously Injured Overhead Athletes during a Seated Throw Jenny McConnell, 1 Cyril Donnelly, 2 Samuel Hamner, 3 James Dunne, 2 Thor Besier 4 1 Center for Sports Medicine, University of Melbourne, Melbourne, Australia, 2 School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia, 3 Department of Mechanical Engineering, Stanford University, Palo Alto, California, 4 Human Performance Laboratory, Department of Orthopaedics, Stanford University, Palo Alto, California Received 3 October 2010; accepted 7 February 2011 Published online 15 March 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI /jor ABSTRACT: The purpose of our study was to investigate whether shoulder taping affects shoulder kinematics in injured and previously injured overhead athletes during a seated throw. Twenty-six overhead college athletes threw a handball three times with and without tape, while seated on a chair. An 8-camera Vicon Motion Capture system recorded markers placed on the upper limb and trunk during each of the throwing conditions. Scaled musculoskeletal models of the upper limb were created using OpenSim and inverse kinematics used to obtain relevant joint angles. Shoulder taping had no main effect on external (ER) and internal (IR) rotation range (ROM) of the shoulder, but a significant interaction effect was found (p ¼ and 0.02, respectively), depending on previous injury status, whereby both the ER and IR ROM of the shoulder in the group of previously injured athletes decreased when taped ( and , respectively), but increased in the group who had never been injured ( and , respectively). Maximum abduction range and ball velocity were not affected by the application of shoulder taping, regardless of previous injury status. Thus, application of shoulder taping has a differential effect on maximum shoulder ER and IR ROM during throwing depending on previous injury status. These findings have implications for returning athletes to sport after injury and for screening athletes at risk of injury. ß 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: , 2011 Keywords: shoulder; taping; rotation range; volleyball; tennis Shoulder injuries are common in overhead athletes with the incidence ranging from 25% to 60%. 1 4 The forceful and repetitive nature of overhead activities is hypothesized to cause microtrauma to the anterior capsule, causing an anterior shift of the humeral head, changing the rotational arc of the shoulder, increasing external rotation (ER) and decreasing internal rotation (IR). 4 7 Burkhart et al. 7 suggested that the shoulder is susceptible to injury if an athlete demonstrates glenohumeral IR deficit, where the increase in ER is less than the decrease in IR, so the rotational arc is 10% less than the contralateral side. Alteration in the coordination of the scapular muscles (scapular dyskinesis) during throwing has also been suggested to cause this anterior shift of the humeral head, increasing the risk of shoulder dysfunction. 2,6 8 Many investigators have shown the change in the rotational axis of the throwing shoulder is due to humeral retrotorsion from repetitive, large rotational loads applied to the proximal physis during overhead activities Throwers with chronic shoulder pain have less humeral retrotorsion, suggesting they have more strain on their anterior capsules during overhead activities, so are more likely to develop chronic pain. 10 The causes of shoulder injuries and pain in overhead athletes are multi-factorial, and many issues must be addressed if treatment is to be effective. Applying tape to the shoulder either to the humeral head or scapula Correspondence to: Jenny McConnell (T: þ ; F: þ ; jennymcconnell@bigpond.com) ß 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. has been utilized as a method of minimizing pain in symptomatic individuals. Scapular taping causes an immediate decrease in shoulder pain. 12,13 One study demonstrated that taping was effective in decreasing upper trapezius and increasing lower trapezius activity in individuals with shoulder impingement during overhead reaching tasks, thus improving scapular dyskinesis. 12 However, studies on the effectiveness of tape around the shoulder in asymptomatic individuals are disparate. Some report no difference between the tape and no tape conditions for scapular muscle activation, 14 joint laxity, proprioception, or handball accuracy, 15 whereas others found an alteration in scapular muscle activation with tape 16,17 McConnell and McIntosh 18 found in elite junior tennis players with no history of shoulder injury that shoulder taping, not placebo taping (tape applied in the same position without tension), increased the passive range of ER and IR ROM of the throwing shoulder, hypothesizing that taping the shoulder improved the anterior shift. To date, no studies have been conducted investigating the effectiveness of shoulder taping on shoulder kinematics during a fast, dynamic activity such as throwing. As shoulder tape is increasingly being used for athletes for both therapeutic and prophylactic reasons, and as both excessive and restricted shoulder ER ROM is hypothesized to cause shoulder injuries, we aimed to investigate whether taping affected shoulder kinematics, particularly maximum ER ROM during a seated throw. If tape had an effect, a secondary aim was to determine whether the effect 1406

2 TAPE EFFECT ON SHOULDER ROTATION 1407 was similar for the uninjured and previously injured, now asymptomatic, overhead athletes. Additionally, we wanted to determine whether tape on the shoulder influenced ball velocity. METHODS Subjects Twenty-six elite college overhead athletes (mean age 20 years, range years) from Stanford University volleyball, baseball, and tennis teams participated in the study (Table 1). Subjects were excluded if they had a current shoulder injury making them unable to play or train in their selected sport, or if they could not perform a maximal effort throw. The subjects completed a questionnaire regarding their training schedule, years spent playing their sport, and details of injuries including location, time off from sport, and, if it were a shoulder injury, the type of treatment received and if they needed to modify their overhead activity as a result of the injury. All individuals provided informed written consent, and ethics approval was obtained from the University s Institutional Review Board. Procedure Subjects were seated on a chair and threw a handball into a net (Fig. 1). The use of a seated throw isolated the throwing to the upper body and decreased the variability of the throwing action of athletes from different sports. The subjects warmed up for 1 min by gradually increasing their throwing intensity. The subjects were asked to perform three maximal throws. The average of the three throws was used for data analysis. Throwing trials were repeated with and without shoulder taping using the taping protocol of McConnell and McIntosh 18 (Fig. 2). The no tape and tape conditions were randomly assigned. Subjects rested for 5 min between the two conditions and performed the same warm up for each condition. Data Collection An 8-camera Vicon Motion Capture system (Oxford Metrics, Oxford, UK), operating at a rate of 120 Hz, recorded markers placed on the upper limb and trunk. Anatomical markers were placed on: the anterior and posterior superior iliac spines of the pelvis; sternal notch; spinous process of C7; distal clavicle of the throwing arm; head of the ulna; and head of the radius. Clusters of three markers were placed on the upper arm and forearm of the throwing limb. These marker clusters were used to track arm motion during the throw. A static calibration trial was captured prior to the throwing trials, which included markers placed on the medial and lateral humeral epicondyles (to define the elbow joint center), medial and lateral aspects of the radial and ulnar heads (to define the wrist joint center), acromion process, and anterior Figure 1. a net. Experimental set up, subject seated throwing into and superior aspects of the shoulder, 2 cm below the acromion (to define the shoulder joint center). A kinematic model of the upper limb 19 was scaled to match the estimated joint centers from the static calibration trial, and inverse kinematics was used to estimate motions of the shoulder (3 degrees of freedom [dof]) and elbow (2 dof) using OpenSim software 20 (Fig. 3). Kinematic variables were determined by visual inspection from the Vicon workstation. 21 Peak external shoulder rotation was measured one frame after full cock with initiation of elbow velocity in the sagittal plane. Peak IR was measured at zero elbow velocity after ball release. Zero elbow velocity was defined as the frame following ball release where elbow movement was zero in the sagittal plane. Ball release was defined as the frame in which the ball and hand were no longer in contact (Fig. 4). Statistical Analysis To determine any main effects of tape on shoulder ROM, 2-way repeated measures ANOVAs were performed, and any Table 1. Subject Characteristics Age (years) Height (cm) Weight (kg) Mean SD Mean SD Mean SD Volleyball Tennis Baseball All (3 M, 10 F) 7 (6 M, 1 F) 6 (M) Uninjured (6 F) 6 (5 M, 1 F) 5 (M) Injured (3 M, 4 F) 1 (M) 1 (M) M, male; F, female.

3 1408 MCCONNELL ET AL. Figure 4. Shoulder abduction, elevation angle, and shoulder rotation from Full cock (A) to zero elbow velocity (C) in sagittal plane. The dashed line represents when ball release (B) occurs. Figure 2. Subject in the taped condition, markers in situ ready to throw handball. interaction effect of previous injury status determined. Each subject served as their own control. Measures for each subject were obtained for the no tape and tape conditions. Confidence intervals (CI) at 95% for differences between conditions were calculated; an alpha of p < 0.05 was used to determine significance. For all comparisons, the exact p-value is reported along with the effect size, calculated using Cohen s d. 22 Statistical analyses were performed using SPSS v17.0 (SPSS, Inc., Chicago, IL). RESULTS All the athletes who had indicated they had suffered previous shoulder problems were fully participating in their sports. Two athletes (both volleyball players) felt they had modified their overhead techniques because of their shoulder injury. Most of the previously injured athletes had received physical therapy for their injuries, but none had needed surgery. No main effect of shoulder taping was found on maximum ER and IR, shoulder abduction ROM, or ball velocity (Table 2). However, a significant interaction effect of shoulder taping was found depending on previous injury status (p ¼ 0.003), on maximum ER, which increased with tape from 131 to 1358 in the uninjured group (17 subjects) and decreased with tape from 143 to 1388 in the previously injured group (nine subjects) (Fig. 5). Similarly, a significant interaction effect occurred with IR with previous injury status (p ¼ 0.02), with tape increasing the range from 42 to 448 in the uninjured and decreasing the range from 54 to 518 in the previously injured (Fig. 6). Total rotation ROM in the previously injured was therefore decreased by tape from 197 to 1888, whereas for the uninjured group, it increased with tape from 174 to 1788, a significant interaction effect (p ¼ 0.003) (Table 2). No interaction effect was found with shoulder taping and previous injury status with shoulder abduction or ball velocity. DISCUSSION The glenohumeral joint is extremely mobile, relying on the passive and active soft tissues for stability. As overhead athletes are often using their shoulders at the end of their ER ROM to achieve maximal upper limb velocity, shoulder pain, and injuries are common in these athletes. Speculation exists as to the Figure 3. Sagittal view of full-cock (A), ball-release (B), and zero elbow velocity (C) events used to define the release (A to B) and breaking (B to C) phases of an overhead seated throw.

4 TAPE EFFECT ON SHOULDER ROTATION 1409 Table 2. Within Subject Kinematic Comparisons of No Tape and Taped Conditions during a Seated Throw Untaped Mean SD Taped Mean SD p-value for Main Effect All Subjects Tape/No Tape p-value for Interaction Effect With Injury Status Effect Size Ball velocity (m/s) Angle in degrees Shoulder max ER (uninjured) Shoulder max ER (prev injured) Shoulder IR at ZEV (uninjured) Shoulder IR at ZEV (prev injured) Shoulder total rotation (uninjured) Shoulder total rotation (prev injured) Shoulder Ab just after FC (uninjured) Shoulder Ab just after FC (prev injured) ER, external rotation; IR, internal rotation; Ab, abduction; max, maximum; prev, previous; ZEV, zero elbow velocity; FC, full cock. mechanism of these injuries, whether it is due to: elongation of the anterior structures, allowing increased anterior translation of the humeral head; tightness of the posterior capsule, causing a limitation of IR range relative to the increases in ER; scapular dyskinesis, resulting in an unstable platform for shoulder movement; or a bony torsion of the humerus, causing an adaptive increase in ER We investigated the effect of a therapeutic intervention, shoulder taping, on the dynamic shoulder kinematics in two groups of asymptomatic overhead athletes an uninjured group and a previously injured group. We found that taping the shoulder had an almost equal and opposite effect on shoulder rotation during throwing depending on the history, with the previously injured group demonstrating a 5% decrease in rotation ROM and the uninjured group demonstrating a 3% increase. An ideal amount of ER may exists for which the shoulder is stable and the anterior structures are not placed under large strains. If the athlete does not have sufficient ER ROM, perhaps because there is less humeral retrotorsion, more strain may exist on the anterior structures of the shoulder, so the shoulder is more susceptible to injury. 10 Jobe and Figure 5. Means of the maximum external rotation range of the shoulder in the no tape and tape conditions for the uninjured and previously injured overhead athletes. Figure 6. Means of the maximum internal rotation range of the shoulder in the no tape and tape conditions for the uninjured and previously injured overhead athletes.

5 1410 MCCONNELL ET AL. Pink 5 postulated that athletes who exhibit increased ER ROM have increased laxity in the antero-inferior capsuloligamentous structures that increases the micro-instability of the shoulder and the athlete s potential for pain. Increased AP and inferior translations associated with elongation of the anterior band of the inferior glenohumeral ligament were found in cadavers when ER was forced beyond the normal limits of passive ER range. 23 Kedgley et al. 24 found greater translations of the humeral head occurred during passive motion than during simulated active loading of the rotator cuff and the deltoid, where the motion was reduced by 1.5 mm. Shoulder taping may reduce the anterior translation of the humeral head by altering the muscle activation patterns of the rotator cuff and/or the scapular stabilizers. Marked changes in function have been associated with small movement and ROM changes. Mihata et al. 25 found that cutting the posterior band of the anterior oblique ligament of the ulnar collateral ligament in cadavers increased apparent shoulder ER by 4.18 when compared to the ER ROM when the elbows were intact. Delp and Maloney 26 found that a 2 cm change in the hip center location affected the force and moment generating capacity of the hip musculature by almost 50%, whereas Amed et al. 27 found that only a 5 mm lateral displacement of the patella decreased the tension in the vastus medialis obliquus by 50%. Small changes in the location of the shoulder joint center could significantly affect the moment generating capacity of the shoulder muscles. Therefore, although taping only produced a 4 68 change in ER ROM during throwing, this small change in range could have great clinical significance for the stability and mobility of the shoulder. An athlete may be pain-free and ready to return to sport, but the muscle requirements may be still insufficient to control excessive anterior translation of the humeral head, changing the shoulder mechanics, perhaps resulting in further injury or decreased performance. The incidence of shoulder re-injury, particularly rotator cuff strain, is high and more common than a new injury. 28 Therefore, shoulder taping may be useful, particularly when the athlete first returns to sport, for improving shoulder kinematics, and minimizing the risk of re-injury, by decreasing the maximum ER and IR of the shoulder, thus controlling the excessive range of shoulder motion during overhead activities. Shoulder taping increased the maximal ER and IR for the asymptomatic group by almost 48. Repetitive overhead activities may cause a change in the center of axis of rotation in the dominant arm, so shoulder taping may alter the rotation starting position, supporting the findings of McConnell and McIntosh, 18 who found shoulder taping increased the passive ER and IR ROM of the shoulder. Clinicians could use shoulder taping as a screening tool to determine an athlete s susceptibility to shoulder injury by measuring shoulder ROM pre and post tape. If taping increases the dynamic shoulder ER and IR ROM, any ROM deficit could be redressed during training. However, taping did not impede or improve the athletes throwing ability, as neither abduction range nor ball velocity were affected, regardless of previous injury status, but we did not analyze the accuracy of the throw. All the athletes in our study were participating fully in their sports, because we wanted to eliminate pain as a confounding variable. Many studies on shoulder taping for asymptomatic individuals were equivocal in their findings and often have only examined the effects of placing tape (placebo) on the shoulder or scapula Only a few studies examined the effect of tape on a pain free, previously injured group. Bennell et al. 29 found that therapeutic tape, not placebo tape, when applied to the patella of previously symptomatic patellofemoral pain subjects, resulted in increased knee flexion in the stance phase of gait. Similarly, Kilbreath et al. 30 found that therapeutic gluteal taping, not placebo taping, improved hip extension at the end of single support in subjects who had experienced a stroke between 2 and 10 years previously. Kilbreath et al. 30 concluded that therapeutic taping may assist the hip extensors to produce a greater force. The same hypothesis may apply to subjects with previously injured shoulders, where taping may enhance the neuromotor control of the rotator cuff and scapular stabilizing muscles, providing a more stable platform for overhead activity. 17 Further studies are required to establish the mechanisms for the effects of shoulder taping during throwing. Limitations of our study included that we tested a relatively small number of athletes from a variety of sports, and most of the previously injured subjects were volleyball players. Although a seated throw allowed us to standardize the throwing technique, it may not represent how these athletes use their shoulders when playing their sport, so the testing protocol may have altered the range of motion required at the shoulder. However, the same position was used for both the tape and no tape conditions, and the tape condition was randomized during testing. We used a standard handball that was an unfamiliar ball type for all the athletes in this study, so this could have influenced throwing performance, but none of the athletes commented on the ball, and all the athletes were allowed to throw for one minute before data collection commenced. In conclusion, shoulder taping had a differential effect on shoulder ER rotation range, whereby uninjured overhead athletes increased their ROM, but previously injured athletes decreased their ROM. The fine control of humeral translation may be improved by the specific application of tape, minimizing strain on the anterior structures and improving the stability of the shoulder. These findings have implications for rehabilitating shoulder injuries, returning athletes to sport after injury, and for screening athletes at risk of injury.

6 TAPE EFFECT ON SHOULDER ROTATION 1411 ACKNOWLEDGMENTS This study was funded by the NSW Sporting Injuries Committee. The authors thank Rebecca Shultz from the Human Performance Laboratory at Stanford for her help with data collection, Roger Adams from the University of Sydney for his statistical help, Eitan Gelber for his enthusiasm for organizing the subjects, and the Stanford athletes for being involved in the study. REFERENCES 1. Lo YP, Hsu YC, Chan KM Epidemiology of shoulder impingement in upper arm sports events. Br J Sports Med 24: Kibler WB, Safran M Tennis injuries. Med Sport Sci 48: Reeser JC, Joy EA, Porucznik CA, et al Risk factors for volleyball-related shoulder pain and dysfunction. PM&R 2: 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 34: Jobe FW, Pink M Classification and treatment of shoulder dysfunction in the overhead athlete. J Orthop Sports Phys Ther 18: Van der Hoeven H, Kibler WB Shoulder injuries in tennis players. Br J Sports Med 40: Burkhart SS, Morgan CD, Kibler WB The disabled throwing shoulder: spectrum of pathology. Part I: pathoanatomy and biomechanics. Arthroscopy 19: Borsa PA, Laudner KG, Sauers EL Mobility and stability adaptations in the shoulder of the overhead athlete: a theoretical and evidence-based perspective. Sports Med 38: Edelsten G The development of humeral head retrotorsion. J Shoulder Elbow Surg 9: Pieper HG Humeral torsion in the throwing arm of handball players. Am J Sports Med 26: Taylor RE, Zheng C, Jackson RP, et al The phenomenon of twisted growth: humeral torsion in dominant arms of high performance tennis players. Comput Methods Biomech Biomed Eng 12: Selkowitz DM, Chaney C, Stuckey SJ, et al The effects of scapular taping on the surface electromyographic signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome. J Orthop Sports Phys Ther 37: Thelen MD, Dauber JA, Stoneman PD The clinical efficacy of kinesio tape for shoulder pain: a randomized, double-blinded, clinical trial. J Orthop Sports Phys Ther 38: Cools AM, Witvrouw EE, Danneels LA, et al Does taping influence electromyographic muscle activity in the scapular rotators in healthy shoulders? Man Ther 7: Alexander CM, Stynes S, Thomas A, et al Does tape facilitate or inhibit the lower fibres of trapezius? Man Ther 8: Bradley T, Baldwick C, Fischer D, et al Effect of taping on the shoulders of Australian football players. Br J Sports Med 43: Lin JJ, Hung CJ, Yang PL The effects of scapular taping on electromyographic muscle activity and proprioception feedback in healthy shoulders. J Orthop Res 29: McConnell J, McIntosh B The effect of tape on glenohumeral rotation range of motion in elite junior tennis players. Clin J Sport Med 19: Holzbaur KRS, Murray WM, Delp SL A model of the upper extremity for simulating musculoskeletal surgery and analyzing neuromuscular control. Ann Biomed Eng 33: Delp SL, Anderson FC, Arnold AS, et al OpenSim: open-source software to create and analyze dynamic simulations of movement. IEEE Trans Biomed Eng 55: Reid M, Elliott B, Alderson J Lower-limb coordination and shoulder joint mechanics in the tennis serve. Med Sci Sports Exerc 40: Cohen J The t-test for means. In: Statistical power analysis for the behavioral sciences, 2nd ed. NJ: Lawrence Erlbaum Associates; p Mihata T, Lee Y, McGarry MH, et al Excessive humeral external rotation results in increased shoulder laxity. Am J Sports Med 32: Kedgley AE, Mackenzie GA, Ferreira LM, et al Humeral head translation decreases with muscle loading. J Shoulder Elbow Surg 17: Mihata T, Safran MR, McGarry MH, et al Elbow valgus laxity may result in an overestimation of apparent shoulder external rotation during physical examination. Am J Sports Med 36: Delp SL, Maloney W Effects of hip center location on the moment-generating capacity of the muscles. J Biomech 26: Amed A, Shi S, Hyder A, et al The effect of quadriceps tension characteristics on the patellar tracking pattern. In Transactions of the 34th Orthopaedic Research Society, Atlanta, Rauh MJ, Macera CA, Ji M, et al Subsequent injury patterns in girls high school sports. J Athl Train 42: Bennell K, Duncan M, Cowan S Effect of patellar taping on vasti onset timing, knee kinematics, and kinetics in asymptomatic individuals with a delayed onset of vastus medialis oblique. J Orthop Res 24: Kilbreath SL, Perkins S, Crosbie J, et al Gluteal taping improves hip extension during stance phase of walking following stroke. Aust J Physiother 52:53 56.