ASSESSMENT OF SCAPULOTHORACIC AND GLENOHUMERAL FUNCTION AND CONSERVATIVE TREATMENT APPROACHES FOR CHILDREN WITH BRACHIAL PLEXUS BIRTH PALSY

Transcription

1 ASSESSMENT OF SCAPULOTHORACIC AND GLENOHUMERAL FUNCTION AND CONSERVATIVE TREATMENT APPROACHES FOR CHILDREN WITH BRACHIAL PLEXUS BIRTH PALSY by Stephanie A. Russo A dissertation submitted to the Faculty of the University of Delaware in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomechanics and Movement Science Spring Stephanie Russo All Rights Reserved

2 UMI Number: All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, MI

3 ASSESSMENT OF SCAPULOTHORACIC AND GLENOHUMERAL FUNCTION AND CONSERVATIVE TREATMENT APPROACHES FOR CHILDREN WITH BRACHIAL PLEXUS BIRTH PALSY by Stephanie Russo Approved: Charles B. Swanik, Ph.D. Director of the Biomechanics and Movement Science Program Approved: Kathleen S. Matt, Ph.D. Dean of the College of Health Sciences Approved: James G. Richards, Ph.D. Vice Provost for Graduate and Professional Education

4 I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: James G. Richards, Ph.D. Professor in charge of dissertation I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: Jill S. Higginson, Ph.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: William C. Rose, Ph.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: Scott H. Kozin, M.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: Dan A. Zlotolow, M.D. Member of dissertation committee

5 ACKNOWLEDGMENTS This work would not have been possible without the support of my family and friends. I would like to thank each of my committee members for helping me develop a project that aligned with my long-term career and research interests. This would not have come together without Dr. Richards unwavering support and efforts to make my circuitous route through school as smooth as possible. The collaborations developed with Philadelphia Shriners Hospital have, without a doubt, changed the path of my career and life for the better. This project would have been impossible without the help of the Motion Analysis Lab team at Shriners and Luisa Rodriguez for believing she could move mountains - or at least scapulas - with two small pieces of tape. Kristen Nicholson, thank you for always jumping in when I need a hand, or a shoulder; and thanks each of my labmates and fellow BIOMS students for sharing in this journey over the last four years. iv

6 TABLE OF CONTENTS LIST OF TABLES... vii LIST OF FIGURES... viii ABSTRACT... ix Chapter 1 INTRODUCTION... 1 Aim 1: Determine ST and GH parameters involved in achieving hand to spine modified Mallet position... 4 Aim 1: Hypotheses... 4 Aim 2: Determine the effectiveness of scapular stabilization during passive stretching of the GH joint and the accuracy of clinical evaluations of shoulder range of motion... 5 Aim 2: Hypotheses... 5 Aim 3: Determine the effect of therapeutic taping on ST and GH joint function... 6 Aim 3: Hypotheses GLENOHUMERAL EXTENSION: AN IMPORTANT FACTOR FOR REACHING BEHIND THE BACK... 8 Introduction... 8 Methods Results Discussion EVALUATION OF SHOULDER RANGE OF MOTION MEASURES AND STRETCHING TECHNIQUES Introduction Methods Results v

7 Discussion POTENTIAL BENEFIT OF THERAPEUTIC TAPING FOR SCAPULAR STABILIZATION Introduction Methods Results Discussion CONCLUSION REFERENCES Appendix A SUBJECT MALLET SCORES AND JOINT ANGLES B SHOULDER JOINT STRETCH DATA C JOINT ANGLE MEASUREMENT TECHNIQUES D INSTITUTIONAL REVIEW BOARD APPROVAL DOCUMENTS vi

8 LIST OF TABLES Table 1 Subject characteristics and surgical histories related to the shoulder Table 2 Means ± standard deviations of each measurement technique in degrees Table 3 Subject histories and previous shoulder surgeries Table 4 Scapulothoracic (ST), glenohumeral (GH) and humerothoracic (HT) joint angles (mean ± standard deviation [SD] in degrees) that demonstrated statistically significant differences with scapular taping. 34 Table 5 Modified Mallet scores and joint angles for each subject Table 6 Table 7 Table 8 Table 9 Table 10 Scapulothoracic joint displacements for the abduction stretch with and without scapular stabilization Glenohumeral joint displacements for the abduction stretch with and without scapular stabilization Scapulothoracic joint displacements for the external rotation stretch with and without scapular stabilization Glenohumeral joint displacements for the external rotation stretch with and without scapular stabilization Glenohumeral cross-body adduction and humerothoracic external rotation angles determined by motion capture, goniometer and clinical estimate vii

9 LIST OF FIGURES Figure 1 Modified Mallet classification Figure 2 Figure 3 Figure 4 Marker placement. Scapular markers on the trigonum spinae and inferior angle were repalpated in each tested position Scapulothoracic (a) and glenohumeral (c) cross-body adduction angles. The middle image (b) demonstrates glenohumeral cross-body abduction as the long axis of the humerus is posterior to the plane of the scapula Kinsio tape applied to the left shoulder to augment middle and lower trapezius for scapular stabilization viii

10 ABSTRACT Approximately one out of every 1000 live births results in a brachial plexus injury that causes sustained impairments, including reduced strength and range of motion, scapular winging and glenohumeral dysplasia. Children with brachial plexus birth palsy have difficulty with movements such as reaching behind their backs. Early, conservative interventions, such as passive stretching and therapeutic taping, are focused on maximizing range of motion. Clinical assessment of passive range of motion is important for determining appropriate treatment plans. The purpose of this study was to determine which scapulothoracic and glenohumeral motions are needed to reach behind one s back, whether scapular stabilization for passive stretching improves the stretch achieved at the glenohumeral joint, the accuracy of different measurement techniques of glenohumeral and humerothoracic range of motion, and the effect of scapular taping on scapulothoracic and glenohumeral joint function. Children with brachial plexus birth palsy were recruited for this study. Modified Mallet scores and clinical estimates of passive humerothoracic external rotation and glenohumeral cross-body adduction were determined by a pediatric hand surgeon. Humerothoracic external rotation and glenohumeral cross-body adduction were also measured with a goniometer by an occupational therapist. Finally, humerothoracic, scapulothoracic and glenohumeral joint angles were measured using a motion capture system. Subjects held their arms in a neutral, resting position and actively held each of the modified Mallet positions. Additionally, passive cross-body adduction was measured, as well as external rotation and abduction stretches with and ix

11 without scapular stabilization performed by an occupational therapist. An occupational therapist certified in Kinesio taping then applied Kinesio tape to augment the lower and middle trapezius. Subjects then repeated the neutral position and each of the modified Mallet positions. A combination of glenohumeral extension and internal rotation was needed to achieve the hand to spine position. For passive stretching, scapular stabilization did not increase stretch at the glenohumeral joint; in fact, it was decreased in abduction. There were no significant differences between the clinical estimate, goniometer measure and motion capture measure for glenohumeral cross-body adduction; however, all three measurement techniques were significantly different than each other for humerothoracic external rotation. Finally, Kinesio taping reduced scapular winging and demonstrated potential for providing stretch to the glenohumeral joint. The findings of this study support the inclusion of the hand to belly internal rotation position in the modified Mallet classification as a better measure of functional internal rotation than the hand to spine position, which requires both glenohumeral internal rotation and extension. Additionally, scapular stabilization during passive stretching hindered stretch at the glenohumeral joint in the population assessed in this study. However, scapular stabilization may be more effective in infants and this should be investigated further. Performing measurements of joint range of motion over time to monitor progress and assess intervention outcomes by the same clinician using the same measurement technique may reduce the risk of error. Finally, Kinesio taping for scapular stabilization has the potential to improve scapulothoracic and glenohumeral joint function; however, further studies are needed to investigate the long-term effects. x

12 Chapter 1 INTRODUCTION The primary goal of this study is to improve understanding of shoulder function and intervention efficacy in children with brachial plexus birth palsy (BPBP). Brachial plexus birth palsy (BPBP) occurs in approximately 0.4 to 4.6 of every 1000 live births [1-3]. The most common type of BPBP affects the upper trunk of the brachial plexus (C5 and C6) and is referred to as Erb s palsy [4, 5]. Damage to C5, C6 and C7, or extended Erb s palsy, is the next most frequent classification of BPBP [5]. While some infants fully recover, approximately one-third of these patients experience lifelong complications [1, 6]. Residual BPBP is known to cause a number of anatomical changes and functional deficits of the affected upper extremity including: reduced limb length [7-9] and girth [8, 9], abnormal scapular morphology [4, 10-16], glenohumeral (GH) dysplasia and subluxation [4, 10, 13-21], muscle weakness and range of motion limitations [9, 13, 22-25]. These effects of BPBP have a dramatic impact on self-reports of function and quality of life in these children. Mean reported upper-extremity subscores on the Pediatric Outcomes Data Collection Instrument for children with BPBP range from and are substantially lower than typicallydeveloping control children whose reported subscores range from [26, 27]. Additionally, these scores reflect less satisfaction with upper extremity function than the mean subscore of 84.6 reported in children with unilateral upper extremity amputation [28]. 1

13 Clinical measures, such as the modified Mallet classification, are used to assess development and progression over time, as well as functional outcomes of surgery [9, 29]; however, these measures provide no information regarding the scapulothoracic (ST) or GH contributions utilized to achieve these tasks [23, 24, 30]. Knowledge regarding ST and GH function is critical because coordinated control of ST and GH movement is necessary for typical shoulder motion [12, 31]. Additionally, a number of both conservative and surgical interventions commonly applied to the BPBP population target either ST or GH function. Currently, reliable, quantitative measures of ST and GH joint contributions remain difficult to obtain [32-37]. Bone pins, radiographic imaging and magnetic resonance imaging are accurate, but all are either exceedingly invasive or expensive, limited to static positions within a confined range of motion and, in the case of radiographic imaging, involve radiation exposure [13, 35, 38-40]. Scapular tracking jigs designed to help identify scapular orientation are cumbersome to use and must be held in place by the clinician during measurement [32, 35, 41, 42]. Magnetic tracking sensors or marker clusters fixed to the acromion process enable dynamic, 3D kinematics [32, 34, 35], but soft tissue deformation at the attachment site leads to poor accuracy [41, 43]. Additionally, regression modeling to predict the orientation of the scapula has also been reported [44], but the results are not useful in clinical settings. The equations, developed using data from a group of 10 subjects, lacked precision and reflected an approach based on tendencies averaged within a group of subjects. Applying this approach to groups with much greater individual variability (such as BPBP patients) would result in estimates of ST orientation that would be useless when applied to an individual patient. Finally, palpation has been determined to be accurate 2

14 to within two degrees for static, 3D measurements of scapular orientation [45]. Despite the high accuracy associated with palpation, the recording of palpated orientations in three-dimensions has not been developed for clinical use. Measurement of humerothoracic (HT) kinematics has been recommended [37]; however, this approach sacrifices valuable information regarding ST and GH function, particularly when the patient population of interest is undergoing surgical interventions designed to improve GH function. Due to the difficulty in accurately measuring scapular orientation [23, 24, 32], knowledge of upper extremity function lags behind understanding of lower extremity function [23, 24, 46]. The ability to describe ST and GH function is anticipated to facilitate clinical assessment and treatment planning of upper extremity conditions including BPBP [12]. For example, further investigation of the ST and GH movement strategies utilized to achieve tasks that are particularly difficult for children with BPBP to perform, such as reaching behind their backs, will help clinicians better understand this functional deficit. Improved understanding of how the task is achieved in unaffected limbs and what factors limit performance of this task in limbs affected by BPBP may help in the development of new intervention strategies to improve functionality of children with BPBP. Additionally, there are a number of interventions currently utilized for children with BPBP that have limited evidence demonstrating clinical benefit, including scapular stabilization during passive stretching of the structures surrounding the GH joint and therapeutic taping of the shoulder. Quantifying the effects of such interventions on ST, GH and humerothoracic (HT) function will provide objective evidence supporting or refuting these commonly utilized interventions. 3

15 The expected outcomes of this study include: 1) better understanding of the ST and GH displacements that contribute to performance of a task that is difficult for nearly all children with BPBP, 2) improved understanding of the impact of scapular stabilization on passive stretching and 3) evaluation of the efficacy of therapeutic taping on ST, GH and HT function. These findings address important voids in the current understanding of shoulder function and intervention validity. Aim 1: Determine ST and GH parameters involved in achieving hand to spine modified Mallet position Imbalance between the shoulder rotators often leads to an internal rotation contracture of the shoulder in children with BPBP [4, 5, 18, 21, 24, 25, 47-53]. There are a variety of surgeries that aim to improve external rotation, but a risk of these procedures is loss of too much internal rotation [5, 18, 29, 50, 52-55]. Traditionally, the hand to spine Mallet position has been considered a measure of shoulder internal rotation [29, 54]; however, an additional internal rotation position has been recommended for better assessment of midline function [9, 29]. Many children with BPBP have difficulty performing the hand to spine position, making it difficult to measure loss of internal rotation using the hand to spine Mallet score as an outcome measure [29, 54]. Furthermore, poor hand to spine performance may be associated with limited GH extension, in addition to internal rotation [56]. Aim 1: Hypotheses There were eight hypotheses associated with this aim. (1) GH extension in the hand to spine position will be significantly greater in children who achieve a Mallet score of 3 or higher than children with Mallet scores of 2 or lower. (2) GH internal rotation in the hand to spine position will be significantly greater in children who 4

16 achieve a Mallet score of 3 or higher than children with Mallet scores of 2 or lower. (3) ST horizontal adduction will negatively correlate with hand on spine performance. (4) GH horizontal adduction will positively correlate with hand on spine performance. (5) GH extension will positively correlate with hand on spine performance. (6) GH internal rotation will not correlate with hand on spine performance. (7) Internal rotation modified Mallet score will not correlate with hand on spine Mallet score. (8) GH extension in the hand to spine position will not significantly differ from GH extension in maximal HT extension in the sagittal plane. Aim 2: Determine the effectiveness of scapular stabilization during passive stretching of the GH joint and the accuracy of clinical evaluations of shoulder range of motion BPBP patients typically lack shoulder abduction and external rotation [4, 5, 17, 18, 21, 24, 25, 30, 47-51, 57, 58]. The less affected internal rotators dominate the unbalanced shoulder, and internal rotation contractures develop in many BPBP children. This can lead to GH dysplasia as early as six months of age and may progress to serious deformity, including glenoid retroversion and posterior subluxation of the humeral head, by age two [4, 5, 13, 14, 16, 49, 54, 59, 60]. Early intervention is aimed at the prevention of GH dysplasia. Passive stretching of the GH joint in external rotation with scapular stabilization is recommended beginning in infancy [4, 5, 9, 16, 54, 61-66]. However, shoulder exercises requiring scapular stabilization may be difficult for untrained caretakers to perform correctly [67]. Aim 2: Hypotheses There were three hypotheses associated with this aim. (1) ST displacements would be significantly smaller during passive stretching with scapular stabilization 5

17 performed by a therapist compared to passive stretching without scapular stabilization. (2) GH displacements would be significantly greater during passive stretching with scapular stabilization performed by a therapist compared to passive stretching without scapular stabilization. (3) GH orientations estimated by clinicians, measured by goniometer and measured using a motion capture system would be significantly different. Aim 3: Determine the effect of therapeutic taping on ST and GH joint function Conservative management of BPBP is aimed at preventing muscle tightness and subsequent joint contractures, as well as improving muscle strength. Modalities such as active and passive range of motion exercises, therapeutic taping, splinting and electrical stimulation are frequently utilized [61]. However, little evidence supporting the efficacy of these conservative treatments exists. One case study claimed that a therapeutic taping intervention using Kinesio tape improved GH congruity and decreased scapular winging in a child with BPBP [68]. According to the manufacturer, Kinesio tape reduces muscle fatigue, stimulates strengthening of weak muscles, and assists with awareness [69]. Kinesio tape may promote functional improvement by allowing the child to move in an optimally aligned position [69]. Although it is frequently utilized, evidence demonstrating the efficacy of scapular taping is lacking [70-75]. Aim 3: Hypotheses There were three hypotheses associated with this aim. (1) There would be no change in ST, GH or HT neutral positions with and without therapeutic tape. (2) There would be no change in ST or GH joint displacements measured during the 6

18 modified Mallet positions with and without therapeutic tape in place. (3) There would be no change in ST, GH or HT orientations in the modified Mallet positions with and without therapeutic tape in place. 7

19 Chapter 2 GLENOHUMERAL EXTENSION: AN IMPORTANT FACTOR FOR REACHING BEHIND THE BACK Introduction BPBP often leads to an internal rotation contracture of the shoulder [4, 5, 18, 21, 24, 25, 47-53] and scapular winging [5, 55, 62, 66, 76-78] that is associated with a GH cross-body abduction contracture [77]. There are a variety of secondary surgeries, such as GH joint reductions and tendon transfers, that aim to improve external rotation, but a risk of these procedures is loss of too much internal rotation causing impaired midline function [5, 18, 29, 50, 52-55]. Traditionally, the hand to spine Mallet position has been considered a measure of shoulder internal rotation [29, 54]. However, many children with BPBP have difficulty performing this task before surgery making it difficult to detect functional loss using the hand to spine Mallet score as an outcome measure [29, 54]. This led to recommendation for a modified Mallet classification (Figure 1) that adds an internal rotation position, which is tested by asking children to place their palms on their bellies [9, 29]. 8

20 Figure 1 Modified Mallet classification. Observation of children performing the modified Mallet classification indicated that children with BPBP often have difficulty executing the hand to spine task in the presence of seemingly adequate shoulder internal rotation. This suggests that additional factors aside from sufficient internal rotation are necessary for successful performance of this task. A previous evaluation of the ST and GH contributions to the modified Mallet positions suggested that difficulty performing the hand to spine position may be related to a lack of GH extension [56]. Additionally, increased scapular winging (ST cross-body adduction) is associated with decreased GH cross-body adduction [77]. Successful completion of the hand to spine position 9

21 requires some degree of ST cross-body adduction. However, too much ST cross-body adduction may make productive GH motion difficult; therefore, we postulated that increased ST cross-body adduction and/or decreased GH cross-body adduction may be associated with poor performance of this task. The purpose of this study was to determine the ST and GH parameters involved in successful performance of the hand to spine position. We hypothesized that GH internal rotation and GH extension in the hand to spine position would each be significantly greater in children who achieve a hand to spine Mallet score of three or higher than children with Mallet scores of two or lower. We also hypothesized that GH cross-body adduction and GH extension would positively correlate with the hand on spine Mallet score, while ST cross-body adduction would negatively correlate with it. Additionally, we hypothesized that the neither the GH internal rotation angle nor the internal rotation modified Mallet score would not correlate with the hand on spine Mallet score. Finally, we hypothesized that the GH extension angle in the hand to spine position represents maximal GH extension and, therefore, would not be significantly different from the GH extension angle in maximal HT extension in the sagittal plane. Methods Thirty-two children (8.9 ± 3.9 years) with BPBP were recruited for this study following the informed consent/assent procedures of Philadelphia Shriners Hospital for Children and the University of Delaware. Modified Mallet scores were determined by a pediatric hand surgeon. A seven-camera motion capture system (Motion Analysis Corporation, Santa Rosa, CA) operating at 60Hz was used to capture the three-dimensional locations of retroreflective markers placed on the following 10

22 anatomic locations: spinous processes of T1, T4 and T8; medial and lateral epicondyles of the humerus; and acromion process, trigonum spinae and inferior angle of the scapula (Figure 2). Coordinate data were collected in the hand to spine and hand to mouth Mallet positions and maximal HT extension in the sagittal plane. The scapular markers placed on the trigonum spinae and inferior angle were re-palpated in each of these positions. The hand to mouth position was used as a measure of ST and GH cross-body adduction because this position requires the most cross-body adduction of the modified Mallet classification positions and has been previously used for assessment of cross-body adduction [77]. Figure 2 Marker placement. Scapular markers on the trigonum spinae and inferior angle were repalpated in each tested position. Coordinate systems for the thorax, scapula and humerus were constructed such that the axes align with those recommended by the International Society of 11

23 Biomechanics (ISB) [79]. Scapulothoracic cross-body adduction and GH cross-body adduction and extension were calculated using a planar projection method with custom-written software (LabVIEW, National Instruments Corporation, Austin, TX) for the hand to spine and hand to mouth positions. Scapulothoracic cross-body adduction was defined as the rotation of the scapula about the thoracic superior/inferior axis in the thoracic transverse plane. If the plane of the scapula were aligned with the thoracic coronal plane, the ST cross-body adduction angle would be zero. The more anterior the scapular plane is relative to the thoracic coronal plane, the larger the ST cross-body adduction angle (Figure 3a). Glenohumeral cross-body adduction was defined as the rotation of the long axis of the humerus about the superior/inferior axis (medial border) of the scapula. When the humerus is abducted in the scapular plane ( scaption ), the cross-body adduction angle is zero. The more anterior the long axis of the humerus is relative to the scapular plane, the larger the GH cross-body adduction angle (Figure 3c). The more posterior the long axis of the humerus is relative to the scapular plane, the larger the GH cross-body abduction angle (Figure 3b). Glenohumeral extension angles were calculated for the hand to spine and maximal extension in the sagittal plane positions. Glenohumeral extension was defined as rotation of the humerus about the medial/lateral axis of the scapula (vector from the trigonum spinae to the acromion process) in the sagittal plane of the scapula. The more posterior the humerus is relative to the scapular plane, the larger the GH extension angle. 12

24 Figure 3 Scapulothoracic (a) and glenohumeral (c) cross-body adduction angles. The middle image (b) demonstrates glenohumeral cross-body abduction as the long axis of the humerus is posterior to the plane of the scapula. This planar projection method deviates from the ISB recommendation of using a specific Euler sequence (YXZ with the X axis in the anterior direction, Y axis in the superior direction and Z axis to the right) for calculation of ST joint angles. However, experts in the field have recommended using a predetermined rotation sequence tailored to the measured motion and have stated that some motions, such as circumduction, are poorly represented by all Euler sequences (see Biomech-L post from Ton Van Den Bogert titled, Re: How to choose Euler angles sequence of rotation posted on 3/12/09). Euler sequences best align with clinical observation of motion when the first rotation in the sequence corresponds to the axis about which the greatest motion occurs and the last rotation occurs about the appropriate axis (usually internal/external rotation) with respect to the distal segment. Therefore, the Euler sequence that is standard for lower extremity gait analysis (i.e. knee, hip) follows the order of flexion/extension, abduction/adduction, internal/external rotation. Without knowing the axis associated with the greatest scapular rotation in the motions tested in this study, it is likely the ISB recommended rotation sequence departs from the 13

25 concept of choosing axes according to amount of rotation in at least some motions and/or select patients. For example, if the scapula s primary rotation for a tested motion is upward/downward rotation, the recommended YXZ order would fail dramatically. Therefore, we elected to utilize an order-independent approach that reliably measures joint angles for all tested motions. Glenohumeral internal rotation and GH extension angles were compared between children with Mallet scores of three or higher and two or lower using a oneway ANOVA (α = 0.05) and compared between the hand to spine position and maximal extension in the thoracic sagittal plane using a one-way ANOVA with repeated measures (α = 0.05). Correlations between hand to spine and internal rotation modified Mallet scores and hand to spine score and ST cross-body adduction angle, GH cross-body adduction angle and GH extension angle were assessed using Pearson s product correlations. A Pearson s correlation coefficient of 0.7 or larger was considered strongly correlated, 0.3 to 0.69 moderately correlated, and less than 0.3 weakly correlated. The statistical analysis was performed using SPSS (SPSS v20, IBM, Armonk, NY). Results Subject characteristics and relevant surgical histories are shown in Table 1. Children with higher hand to spine scores demonstrated significantly (p = 0.005) larger GH extension angles (17.8 vs ) and a nonsignificant (p = 0.099) trend toward increased GH internal rotation angles (24.1 vs. 1.9 ). Additionally, the GH extension angle significantly (p = 0.021) correlated with the hand to spine score (Pearson s r = 0.407). Neither the ST cross-body adduction (p = 0.626) nor the GH cross-body adduction (p = 0.487) angles significantly correlated with the hand to spine 14

26 score. The GH internal rotation angle did significantly correlate (p = 0.030, Pearson s r = 0.384) with the hand to spine score. Hand to spine and internal rotation modified Mallet scores also correlated significantly (p = 0.007, Pearson s r = 0.469). However, of the 13 participants with internal rotation scores of four, hand to spine scores ranged from two (n = 7) to four (n = 4). Finally, glenohumeral extension was significantly (p = 0.002) larger in the hand to spine position (3.8 ) than maximal extension in the sagittal plane (-8.2 ). The complete data are displayed in Appendix A. 15

27 Table 1 Subject characteristics and surgical histories related to the shoulder. Additionally, subject 2 had a triangle tilt procedure, and subject 10 had a pectoralis and subscapularis release. Finally, subject 32 had a posterior capsulodesis. *Indicates the patient had subscapularis release in addition to their tendon transfer. Diagnosis Subject Erb s Extended Total Age Primary nerve surgery Shoulder tendon transfer Arthroscopic release Humeral Osteotomy X* 4 5 X 5 9 X X 6 11 X 7 5 X X X 12 6 X X X X X X X X X* 21 4 X 22 6 X X X 27 8 X X 28 7 X 29 6 X X X X X* 16

28 Discussion The results of this study demonstrate that both sufficient GH extension and internal rotation are needed to successfully reach behind one s back. Children with hand to spine Mallet scores of three or higher utilized significantly more GH extension and demonstrated a trend towards greater GH internal rotation. This was further supported by significant, moderate correlations between the hand to spine Mallet score and (1) the GH extension angle in the hand to spine position, (2) the GH internal rotation angle in the hand to spine position and (3) the internal rotation modified Mallet score. The findings of this study do not support a relationship between ST or GH cross-body adduction and hand to spine performance. Additionally, children demonstrated greater GH extension during the hand to spine task than when they were asked to perform maximal HT extension in the thoracic sagittal plane. This is likely due to the children s ability to use the contact between their hands and torsos to gain further extension in the hand to spine position. This contact point and resultant potential for gaining leverage against the torso was not possible in the maximal extension position. It should also be noted that children were instructed to perform the motion slowly and were neither permitted to walk their hands farther than they could actively reach nor to utilize ballistic, swinging motions. The cohort of patients in this study represented a variety of injury levels and surgical histories, including procedures with a risk of reducing internal rotation. These are potentially confounding factors; however, this represents a realistic sample of the children with BPBP who are assessed using the modified Mallet classification. 17

29 Additionally, the children with no surgical interventions spanned all Mallet scores seen in this cohort. Although both GH extension and internal rotation are used to reach behind the back, the hand to spine Mallet position appears to more consistently test extension than internal rotation, as has been suggested previously [56]. The trend toward greater GH internal rotation with higher hand to spine Mallet scores was not statistically significant. Additionally, the majority of the children with the highest internal rotation modified Mallet scores (score of four) in this cohort, scored only a two for the hand to spine position; however, hand to spine scores for these children ranged from two to four. This variability indicates that the hand to spine position is not a good test of functional internal rotation. Utilizing the hand to belly internal rotation position of the modified Mallet classification for assessment of functional internal rotation, i.e. performance of midline tasks, may be more appropriate [9, 29]. Additionally, these findings corroborate previous assertions that the hand to spine Mallet position is not well suited to pick up functional losses in internal rotation following surgical interventions [29, 54]. While reaching behind one s back also holds value as a measure of the ability to perform activities of daily living such as dressing and toileting, it is important to recognize that it represents a coordinated, multi-planar motion that is difficult to achieve for many children with BPBP and is not a good representation of pure internal rotation. 18

30 Chapter 3 EVALUATION OF SHOULDER RANGE OF MOTION MEASURES AND STRETCHING TECHNIQUES Introduction Brachial plexus injuries affecting the upper trunk of the brachial plexus (C5 and C6) are the most common, representing approximately percent of cases of BPBP [4-6, 9, 61, 80, 81]. Upper trunk injuries, known as Erb s palsy, affect shoulder abduction, shoulder external rotation, elbow flexion and forearm supination [61, 82]. The combination of weak shoulder external rotators and relatively stronger shoulder internal rotators leads to development of an internal rotation contracture at the shoulder and, subsequently, GH joint dysplasia [1, 4, 9, 13, 19, 54, 55, 61-63, 81, 82]. A clinical indication of GH dysplasia is loss of passive external rotation [4, 16, 52, 54, 62, 63, 66, 81-84]. Early management of BPBP is focused on maintaining full passive range of motion of all involved joints. Typically, a home stretching program is initiated around one week of age [66, 82] and supplemented with formal therapy [5, 9, 64, 66, 82]. The mainstay of treatment has been passive GH external rotation stretching with scapular stabilization [4, 5, 9, 16, 54, 61, 62, 64-66], but passive GH stretching in other planes while maintaining scapular stabilization has also been recommended [5, 62, 77]. However, the recommendation for scapular stabilization with passive stretching is based on the assumption that scapular stabilization allows more focused, 19

31 maximal stretch of the GH joint [9, 54, 61, 65], but this has not been evaluated objectively. Monitoring passive shoulder motion over time is important in children with BPBP as loss of passive external rotation is a sign of GH dysplasia and may be an indication for further assessment and intervention [4, 16, 52, 54, 62, 63, 66, 81-84]. However, the validity of the passive range of motion measurements has not been previously established. When assessing passive range of motion, pediatric hand surgeons make a visual estimate of range of motion. However, occupational and physical therapists measure the range of motion using a goniometer. In both cases, the scapula is firmly stabilized against the rib cage while the arm is externally rotated and then the orientation of the humerus relative to the trunk is measured. This practice is based on the theory that with the scapula stabilized against the trunk, the ST orientation will be effectively the same for all patients. Measuring the orientation of the humerus relative to the trunk (the zero axis pointing anteriorly in the thoracic sagittal plane) is easier to visualize and is believed to differ from a true GH measurement by a constant offset between patients. Previously, GH cross-body adduction was not routinely measured. However, decreased GH cross-body adduction is associated with scapular winging, and there is a need to establish a means of clinically measuring GH cross-body adduction. Given the importance of maintaining and measuring passive motion in children with BPBP, this study aimed to determine the most effective means of stretching the GH joint and taking clinical measures of passive joint motion. We hypothesized that ST displacements would be significantly smaller during passive stretching with scapular stabilization performed by an occupational therapist compared to passive 20

32 stretching without scapular stabilization. On the other hand, we hypothesized that GH displacements would be significantly larger during passive stretching with scapular stabilization performed by an occupational therapist compared to passive stretching without scapular stabilization. Additionally, we hypothesized that there would be significant differences between GH and HT joint angles estimated by pediatric hand surgeons, measured by an occupational therapist using a goniometer and measured using a motion capture system. Methods Twenty-six children (9.9 ± 3.2 years) with BPBP were recruited for this study utilizing the institution s informed consent/assent procedures. A pediatric hand surgeon visually estimated each child s passive HT external rotation and passive GH cross-body adduction. Then an occupational therapist measured the same parameters using a goniometer. Motion capture data was then collected without repositioning the child, whenever possible. For the motion capture measurements, markers were placed on the spinous processes of T2 and T8, sternal notch, acromion process and medial and lateral epicondyles of the humerus. Two additional scapular markers, placed on the trigonum spinae and inferior angle, were re-palpated in each position. An eight-camera motion analysis system (Vicon, Centennial, CO) operating at 60Hz collected threedimensional coordinate data in each of the following positions: neutral with the arm resting by the side, external rotation with scapular stabilization, external rotation without scapular stabilization, abduction with scapular stabilization, abduction without scapular stabilization and cross-body adduction in 90 degrees of HT elevation with scapular stabilization. 21

33 Coordinate systems for the thorax, scapula and humerus were constructed such that the axes aligned with those recommended by the ISB [79]. Scapulothoracic joint angles (upward/downward rotation, internal/external rotation and anterior/posterior tilt) were calculated using a helical method [85]. Glenohumeral joint angles (crossbody adduction/abduction, elevation and internal/external rotation) were calculated using a modified globe method [86, 87]. Joint displacements between each tested position and the neutral position were calculated. This method was chosen in spite of the ISB recommendation to use predetermined Euler angle sequences for ST and GH joint angle calculations due to the rationale described in Chapter 2. Similar to planar projection, both helical (or axis-angle) measurements and the globe method are order-independent and do not depend on accurate prediction of the distal segment s primary axis of rotation. For this study, we made two modifications to the previously described globe method [86] to adapt it for use with GH joint angles rather than HT joint angles. First, the scapula was used in place of the thorax as the proximal segment in order to calculate GH joint angles. Second, GH internal/external rotation was calculated such that zero degrees of rotation corresponded to the orientation of the humerus from the neutral trial rotated by the angle of elevation from each trial in the plane of elevation for each trial. The internal or external rotation angle was then determined by calculating the number of degrees the mathematically manipulated neutral humerus needed to be rotated to align with the humerus from each trial. For comparison of ST displacements with passive stretching performed with and without scapular stabilization, one-way MANOVAs (α = 0.05) were run for each position, external rotation and abduction. A Bonferroni correction was applied to account for testing two positions. The factor levels consisted of manual scapular 22

34 stabilization or no scapular stabilization, and the dependent variables were each of the three ST displacements (about the three anatomic axes). In the event of a significant Wilk s Lambda, univariate ANOVAs were performed to determine which ST displacements were significantly different. A Bonferroni correction was also applied to the univariate test. The same procedure was followed for the GH joint displacements. For comparison of joint orientations estimated by clinicians, measured by goniometers and measured by motion capture, the one-way ANOVAs with repeated measures were performed. The factor levels consisted of measurement type (clinical estimate, goniometer and motion capture), and the dependent variables were the GH or HT joint angles. A Bonferroni correction was used to account for testing two positions. The statistical analysis was performed using SPSS (SPSS v20, IBM, Armonk, NY). Motion capture was considered the gold standard. Results The clinical estimate of GH cross-body adduction was not available for one patient, and the motion capture measurement of cross-body adduction could not be collected for one patient. These two subjects were excluded from that portion of the analysis. When comparing passive external rotation stretching with and without scapular stabilization, there were no significant differences in ST displacements (p = 0.133) or GH displacements (p = 0.029), given the Bonferroni correction for multiple comparisons (critical p = 0.025). However, for the abduction stretches, the MANOVAs for both ST (p < 0.001) and GH (p < 0.001) displacements were statistically significant. Univariate ANOVAs revealed that ST upward rotation displacement was significantly decreased (p < 0.001) from 58.4 to 47.0 and ST external rotation displacement was significantly increased (p < 0.001) from 2.5 to 23

35 10.8 with scapular stabilization. Glenohumeral elevation significantly decreased (p < 0.001) from 42.7 to 30.0 and GH external rotation significantly increased (p = 0.003) from 30.2 to 41.0 with scapular stabilization. Individual subjects data are shown in Appendix B. Comparison of clinical estimates, goniometer measurements and motion capture measurements demonstrated no significant differences (p = 0.751) for GH cross-body adduction. However, the MANOVA comparing HT external rotation measures established statistical significance (p < 0.001), and the univariate ANOVAs demonstrated that all measures were significantly different from each other. The motion capture measurement was significantly different from both the clinical estimate (p < 0.001) and goniometer measurement (p = 0.003), and the clinical estimate was significantly different (p = 0.002) from the goniometer measurement. The mean values are shown in Table 2, and the complete data are shown in appendix C. Table 2 Means ± standard deviations of each measurement technique in degrees. (GH Glenohumeral; HT Humerothoracic) Joint Angle Motion Capture GH Cross-body Adduction 27.9 ± 18.4 HT External Rotation 6.7 ± 22.0 Goniometer 27.3 ± ± 23.2 Clinical Estimate 30.0 ± ± 20.2 Discussion Although the effect of scapular stabilization on GH stretching has previously not been objectively assessed, the overwhelming assumption was that scapular stabilization would allow more focused, maximal stretch of the GH joint [9, 54, 61, 24

36 65]. However, passive stretching with scapular stabilization did not improve stretch (assessed by GH displacement) at the GH joint. For external rotation, there were no significant differences in ST and GH joint displacements. However, for abduction, there were significant differences indicating that the scapula was restrained, but not fully prevented from moving. Although there was less upward rotation of the scapula with stabilization, the scapula still upwardly rotated 47.0, on average. Surprisingly, the GH elevation displacement was approximately 13 smaller with scapular stabilization. The lack of significant differences for external rotation stretching with and without scapular stabilization may be due to the anatomic limitations on ST external rotation. The scapula is capable of very little external rotation before abutting the rib cage. Once this position is reached, the rib cage provides sufficient scapular stabilization for the stretch. In abduction, some degree of scapular stabilization was achieved; however, there was still substantial upward rotation of the scapula and less elevation of the GH joint. This may be due to the age of the children assessed in this study. Anecdotally, the occupational therapist noted that scapular stabilization was more difficult in older children. The different measurement techniques (visual estimate, goniometer, and motion capture) were more consistent for GH cross-body adduction than HT external rotation. This is likely due to the procedure used clinically for measuring external rotation as it is not a true measurement of either HT or GH range of motion. True HT range of motion would include both ST and GH motion (i.e. no scapular stabilization), and true GH range of motion needs to be measured with respect to the orientation of the scapula. Measuring true GH external rotation may improve the accuracy of the 25

37 measurements, particularly given that there were no significant differences between the measurements of GH cross-body adduction. The scapular stabilizations for the goniometer measurements and motion capture measurements were performed by the same occupational therapist, while the clinical estimate was performed by a pediatric hand surgeon. Therefore, potential differences due to varying technique or proficiency performing scapular stabilization could not be determined. Another limitation of this study was the age of the participants. Although passive stretching exercises remain important throughout development, particularly during growth spurts, they are especially important in infancy. Scapular stabilization might be more effective in infants as adequate stabilization of a relatively smaller scapula may be easier to achieve. The findings of this study indicate that scapular stabilization may be detrimental to passive stretching of the GH joint in children. However, assessment of stretching with and without scapular stabilization in infants should be performed prior to changing treatment recommendations in this age group. Visual estimates and goniometer measures of external rotation, performed according to current standard of care, were not consistent in this cohort. Until further investigation of intra-rater and inter-rater reliability is performed, clinicians should ensure that the same individual and same measurement technique are used to assess joint range of motion over time, as well as before and after interventions. Additionally, accuracy of passive external rotation measures may improve if the orientation of the humerus relative to the scapula is assessed. 26

38 Chapter 4 POTENTIAL BENEFIT OF THERAPEUTIC TAPING FOR SCAPULAR STABILIZATION Introduction Scapular winging (i.e. ST internal rotation) is a frequent complaint of children with BPBP and their caretakers [55, 62, 66, 76, 77] and is thought to be compensatory for decreased GH cross-body adduction [77]. Similarly, increased ST excursion in all planes has been noted [66, 82]; however, measurement of ST contributions to the modified Mallet positions demonstrated scapular excursion was similar to unaffected limbs, but the resting position of the scapula differed [56]. Conservative treatment for BPBP is aimed at preventing muscle tightness and subsequent joint contractures and includes modalities such as passive and active range of motion exercises, therapeutic taping, splinting, and electrical stimulation [61, 82]. However, there is little objective evidence supporting these treatments [70-75]. Existing reports evaluating the efficacy of scapular taping are inconsistent [68, 70-75, 88-92] and represent different types of tape, tape application techniques and populations [71]. Kinesio tape has been reported to change scapular kinematics [72, 90], muscle activity [70, 90] and proprioceptive feedback index [70]. However, a randomized control trial comparing therapeutic Kinesio taping and sham taping (two strips of Kinesio tape applied without tension) in young adults with rotator cuff pathology found that therapeutic taping did not affect goniometer-measured scapular range of motion during pain-free, maximum active range of motion trials in abduction, 27

39 forward flexion and scapular plane elevation [75]. For children with BPBP, there is one case study reporting improved GH congruity and decreased scapular winging following a therapeutic taping intervention using Kinesio tape [68]. The manufacturer states that Kinesio tape stimulates strengthening of weak muscles, reduces muscle fatigue by providing support, and provides proprioceptive input to assist with awareness [69]. Kinesio tape may encourage functional improvement by allowing the child to move in an optimally aligned position [69]. The purpose of this study was to assess the effect of therapeutic taping intended to stabilize the scapula on ST and GH joint function. We hypothesized that there would be no differences in ST, GH or HT orientations in a resting, neutral position. Additionally, we hypothesized that there would be no differences in the ST, GH or HT joint angles in each of the modified Mallet positions. Finally, we hypothesized that there would be no differences in the ST and GH displacements from the neutral position to each of the modified Mallet positions. Methods Twenty-six children (9.9 ± 3.2 years) with BPBP were recruited for this study following the institution s informed consent/assent procedures. An eight-camera motion analysis system (Vicon, Centennial, CO) operating at 60Hz was used to collect three-dimensional coordinate data of markers placed on the following anatomic landmarks: spinous processes of T2 and T8, sternal notch, acromion process and medial and lateral epicondyles of the humerus. Markers on the trigonum spinae and inferior angle of the scapula were repalpated in each tested position. Data were collected in a neutral position and each of the modified Mallet positions (Figure 1). 28

40 An occupational therapist who is a Certified Kinesio Taping Practitioner then applied Kinesio Tex tape (Kinesio USA, Albuquerque, NM) to augment the middle and lower trapezius (Figure 4) on the affected side. Subjects were asked to maximally retract their scapulae toward their spines, and this motion was manually augmented by the therapist during tape application. The Kinesio tape was anchored laterally and applied toward the spine with paper-off tension [69]. Following application of the tape, the motion capture data were recollected for all positions. As the selected therapeutic taping was intended to augment the middle and lower trapezius, patients who had spinal accessory nerve transfers or lower trapezius tendon transfers were excluded from the study. Additionally, the occupational therapist confirmed that all enrolled subjects were appropriate candidates for scapular stabilization therapeutic taping. The therapist subjectively assessed children for scapular winging that was increased compared to the unaffected limb and could be improved with manual manipulation. Additionally, poor skin integrity or open wounds were considered contraindications for therapeutic taping. 29

41 Figure 4 Kinsio tape applied to the left shoulder to augment middle and lower trapezius for scapular stabilization. Coordinate systems for the thorax, humerus and scapula were constructed such that the axes aligned with those recommended by the ISB [79]. Helical angles were used to calculate the ST joint angles (upward/downward rotation, internal/external rotation and anterior/posterior tilt) [85]. A modified globe method was used to calculate GH and HT joint angles (cross-body adduction/abduction, elevation and internal/external rotation) as described in Chapter 3 [86, 87]. This deviated from the ISB recommended Euler sequences for calculating ST, GH and HT angles. The rationale for selecting order-independent approaches that did not require predetermination of the primary axis of rotation was identical to that described in Chapters 2 and 3. Scapulothoracic and GH joint displacements from the appropriate neutral position to each of the modified Mallet positions were also calculated (neutral 30