Changes in Shoulder Rotation Based on Elevation in Children With Brachial Plexus Birth Injury.

PURPOSE: Lack of shoulder external rotation is common in children with brachial plexus birth injuries. Development of glenohumeral (GH) dysplasia is associated with progressive loss of passive external rotation. Some authors recommend measuring external rotation with the arm adducted, whereas others recommend measurement with the arm in 90° of abduction. The purpose of this study was to compare active and passive external rotation and internal rotation measured in adduction versus abduction. METHODS: Fifteen children with brachial plexus birth injuries held their affected arms in maximal external and internal rotation with the arm adducted and the arm at approximately 90° of abduction. Active and passive rotations were measured with three-dimensional motion capture. Scapulothoracic (ST) internal/external rotation and GH internal/external rotation joint angles were calculated and compared using multivariable, one-way repeated measures analyses of variance. RESULTS: There were no significant differences for active or passive ST rotation in external rotation in adduction versus abduction. Glenohumeral external rotation was significantly increased with the arm in abduction compared with adduction both actively and passively. There were no differences in ST rotation in active versus passive conditions, but all GH rotations were significantly greater passively. CONCLUSIONS: Shoulder internal/external rotation in abduction and adduction is not interchangeable. Comprehensive assessment of shoulder external and internal rotation should include both adduction and abduction. CLINICAL RELEVANCE: For children with brachial plexus birth injuries, both active and passive GH external rotations were greater in abduction. Therefore, early GH joint dysplasia may be missed if GH external rotation is measured in abduction. Additionally, consistency in arm position is important for comparison over time. The entire ST rotation capacity was used to perform maximal internal and external rotation, but the entire passive GH range of motion was not actively used. This highlights an area for potential surgical intervention to improve motion.

Shoulder Motion Overestimated by Mallet Scores.

BACKGROUND: Brachial plexus birth injuries (BPBI) occur in up 0.4 to 4.6 per 1000 live births. Weakness about the shoulder and development of glenohumeral joint contractures are common sequalae of BPBI. Shoulder function in children with BPBI is frequently assessed using the modified Mallet classification to evaluate upper extremity motion deficits. The purpose of this study was to assess the accuracy of the abduction, external rotation, and hand-to-mouth Mallet classification scores in children with BPBI using motion capture. METHODS: A retrospective study of 107 children with BPBI who underwent motion capture assessment and Mallet scores on the same date were reviewed. Motion capture measurements were used to calculate humerothoracic elevation and external rotation joint angles in the abduction/hand-to-mouth and external rotation positions, respectively. The humerothoracic joint angles were converted to the corresponding Mallet scores. Discrepancies between the Mallet scores determined by clinicians and those determined by motion capture were assessed. RESULTS: For abduction, 24.3% of Mallet scores were misclassified during clinical examination. Of the misclassified scores, 22 were overestimated by 1 point and 4 were underestimated by 1 point compared with motion capture. For external rotation, 72.9% of Mallet scores were misclassified during clinical examination. Only 5 patients had an HT elevation that was less than 40 degrees, with 4 of them (80%) having a Mallet hand-to-mouth score of 4. There were no differences in proportion of patients with HT elevation less than 40 degrees who had a Mallet score of 4 or a Mallet score less than 4. CONCLUSIONS: There was better agreement in global abduction Mallet scores compared with external rotation and hand-to-mouth Mallet scores. This difference was likely due to the complex compensatory strategies that patients employ while performing external rotation and hand-to-mouth positions. The inaccuracy of the clinically determined Mallet scores is alarming given that they are frequently utilized to assist with surgical indications and are commonly used as outcome measures. LEVEL OF EVIDENCE: Level IV Case series.

Creating an autoencoder single summary metric to assess gait quality to compare surgical outcomes in children with cerebral palsy: The Shriners Gait Index (SGI).

Gait for individuals with movement disorders varies widely and the variability makes it difficult to assess outcomes of surgical and therapeutic interventions. Although specific joints can be assessed by fewer individual measures, gait depends on multiple parameters making an overall assessment metric difficult to determine. A holistic, summary measure can permit a standard comparison of progress throughout treatments and interventions, and permit more straightforward comparison across varied subjects. We propose a single summary metric (the Shriners Gait Index (SGI)) to represent the quality of gait using a deep learning autoencoder model, which helps to capture the nonlinear statistical relationships among a number of disparate gait metrics. We utilized gait data of 412 individuals under the age of 18 collected from the Motion Analysis Center (MAC) at the Shriners Children's - Chicago. The gait data includes a total of 114 features: temporo-spatial parameters (7), lower extremity kinematics (64), and lower extremity kinetics (43) which were min-max normalized. The developed SGI score captured more than 89% variance of all 144 features using subject-wise cross-validation. Such summary metrics holistically quantify an individual's gait which can then be used to assess the impact of therapeutic interventions. The machine learning approach utilized can be leveraged to create such metrics in a variety of contexts depending on the data available. We also utilized the SGI to compare overall changes to gait after surgery with the goal of improving mobility for individuals with gait disabilities such as Cerebral Palsy.

Lower-extremity kinematics and kinetics differ based on drop vertical jump variation: An assessment of methodology for a return-to-play protocol using motion analysis.

BACKGROUND: The drop vertical jump (DVJ) is commonly used in return-to-play evaluations to assess movement quality and risk during a dynamic task. However, across biomechanics literature, a multitude of DVJ variations have been used, influencing the generalizability and potential interpretation of the reported findings. RESEARCH QUESTION: The purpose of this study was to identify differences in lower extremity kinematics and kinetics between DVJ variations that differ based on horizontal jump distance, verbal instructions, and the use of a jump target. METHODS: A single-group repeated measures design was used in a laboratory setting. Twenty participants were tested, and three-dimensional angles and moments of the pelvis, hip, knee, and ankle were computed. Wilcoxon signed rank tests were performed to determine differences between DVJ variations. RESULTS: Reduced knee flexion at initial contact and greater knee extensor moments across the descent phase were observed with increased horizontal jump distance. Additionally, both verbal instructions and a jump target influenced movement strategies at the pelvis, hip, and knee. Ground reaction forces were found to be similar across conditions and jump height following the first landing increased with a target. SIGNIFICANCE: Although subtle, the biomechanical differences observed between task variations emphasize the importance of standardizing motion analysis protocols for research and clinical decision-making. Given the findings of the current study, the authors recommend using the Half Height variation in patients treated for a knee injury as it will likely be the most indicative of movement quality.

Evaluation of Upper Extremity Reachable Workspace in Children With Brachial Plexus Birth Injury.

PURPOSE: Brachial plexus birth injury (BPBI) results in upper extremity (UE) movement limitations. Current assessments of UE function used to inform clinical decision-making only evaluate a limited set of static postures and/or movements and have been criticized for being insensitive to certain meaningful differences in function. Reachable workspace provides a numeric and visual assessment of global UE movement ability by quantifying the regions in space that patients can reach with their hands, and it can be collected using real-time feedback to elicit a best-effort acquisition of function. This study evaluated the ability of a real-time feedback reachable workspace tool to assess UE movement in BPBI. METHODS: Twenty-two children with BPBI participated. Reachable workspace data were collected with three-dimensional motion capture using real-time visual feedback to measure UE reaching ability in all regions surrounding the body. All outer, far-from-body points reached by the hand were recorded and analyzed by region. A two-way, within-subjects analysis of variance was used to assess interlimb differences in percentage workspace reached and median reach distance for each of the six regions. RESULTS: The affected limb had significantly less percentage workspace reached than the unaffected limb for all six regions (mean interlimb differences by region, 5.7%-38.6%). The affected limb had significantly less median reach distance than the unaffected limb for all six regions (mean interlimb differences by region, 3.1%-36.8%). CONCLUSIONS: The workspace approach was capable of detecting UE movement impairments of the BPBI-affected limb. The reported deficits in workspace on the affected limb correspond to common movement impairments in BPBI, such as limitations in shoulder elevation, external rotation, extension, and elbow extension. CLINICAL RELEVANCE: The real-time feedback reachable workspace tool is sufficiently robust for assessing UE movement impairments in children with BPBI.

Using Motion Analysis in the Evaluation, Treatment & Rehabilitation of Pediatric & Adolescent Knee Injuries: A Review of the Literature.

Three-dimensional motion capture systems may improve evaluation, treatment, and rehabilitation of knee injuries, because quantitative assessment of the knee improves understanding of biomechanical mechanisms. The benefit of using motion analysis in pediatric sports medicine is that it allows closer and more focused evaluation of sports injuries using kinematics, kinetics, and electromyogram with physical and imaging to determine what is happening dynamically during sports. Future research investigating knee injuries should focus on identifying risk factors, assessing the effectiveness of surgical and nonsurgical interventions, and developing return to sport/rehabilitation protocols. The literature is focused on motion capture in adults with knee injuries.

Trunk and lower-extremity kinematics differ based on step-down tap variation: An assessment of methodology for a return-to-play protocol using motion analysis.

BACKGROUND: The step-down tap (SDT) is a commonly used task to assess unilateral neuromuscular control and to identify deficient movement patterns of the trunk and lower extremities. However, instruction of the SDT varies greatly in recent reports, which may alter the clinical interpretation of potential movement deficiencies. RESEARCH QUESTION: The purpose of this study was to identify differences in trunk and lower extremity kinematics between variations of a step-down tap that differ based on step direction, fixing the arms or stance foot, and trial collection methods. METHODS: This study followed a single-group repeated measures design in a laboratory setting. Three-dimensional angles of the trunk, hip, and knee of 18 participants were evaluated at 60 degrees of knee flexion and at maximum squat depth during six SDT variations. Wilcoxon signed rank tests were performed to determine the effects of an anterior verse lateral step direction, a fixed arm or stance foot position, and an individual verse continuous trial collection method. RESULTS: Knee flexion, external pelvic rotation, and external trunk rotation were greater in the anterior SDT, while the lateral SDT elicited greater pelvic tilt and hip flexion. Additionally, overall squat depth was greater across participants during the anterior SDT. Few clinically significant differences (≥3°) were observed due to fixing arm or stance foot position, and no differences were identified based on trial collection methods. SIGNIFICANCE: The standardization of task instructions for motion analysis protocols utilized for research purposes and/or clinical decision-making is crucial. Specifically, for the SDT, the authors recommend using the anterior step direction. A fixed arm and stance foot position is not necessary, and trials may be collected individually or continuously based on convenience for a small number of repetitions.

Assessment of approaches to estimate scapular orientation in children with brachial plexus birth injury.

BACKGROUND: Challenges in measuring dynamic scapular orientation limit assessment of scapulothoracic and glenohumeral contributions to shoulder function in children with brachial plexus birth injury (BPBI). Double calibration acromion marker cluster (D-AMC) and linear model approaches have been validated to estimate scapular motion in healthy adults, but neither has been evaluated in BPBI. RESEARCH QUESTION: Are the linear model and D-AMC approaches able to accurately estimate scapular orientation in children with BPBI at functional arm postures? METHODS: Seventeen children with BPBI positioned their affected limbs in 11 static positions while their segment orientations were measured with motion capture. Linear model and D-AMC estimates of scapular orientation were compared against palpation at six of the static positions with functional relevance to BPBI using a three-way repeat measures ANOVA and a comparison of root mean square errors (RMSE) against literature AMC values for healthy adults. RESULTS: The D-AMC was similar to palpation across all positions and scapular axes while the linear model differed from palpation in a few instances. RMSEs of the D-AMC (3.7-14.8°) and particularly the linear model (4.6-24.8°) were generally at or beyond the upper range of past AMC analyses on healthy adults (1.6-14.2°), especially for more complex, multiplanar arm postures. Despite the D-AMC outperforming the linear model, this approach still produced clinically meaningful (>10°) errors for roughly (12.7-22.5%) of subjects. SIGNIFICANCE: Current methods for estimating dynamic scapular orientation remain less than ideal for BPBI. Use of the D-AMC may be appropriate to gain broad insights into general dynamic scapulothoracic and glenohumeral function; however, given their potential for producing clinically meaningful errors, the D-AMC and linear model are not recommended for diagnostic purposes or outcomes assessment on an individual patient basis unless their patient-specific accuracy has been evaluated and confirmed prior to use.

Comparison of Shoulder Motion Measurements by Visual Estimate, Goniometer and Motion Capture.

BACKGROUND: Brachial plexus birth injuries (BPBI) can result in lasting impairments of external rotation and cross-body adduction (CBA) that disrupt functional activities such as dressing, grooming, or throwing a ball. The purpose of this study was to compare the quantification of shoulder humerothoracic (HT) external rotation (ER), and glenohumeral (GH) CBA by 3 methods - physician visual estimate, goniometer measurement by an occupational therapist, and motion capture. METHODS: Twenty-six patients with BPBI (average age of 9.9±3.2 y) participated in this study. Mallet scores and visual estimates of passive HT ER and GH CBA were recorded by a physician. The passive measures were repeated by an occupational therapist using a goniometer while motion capture measures were simultaneously collected. Active HT ER was also measured by motion capture. The passive measures were compared with analyses of variance with repeated measures, intraclass correlations, and Bland-Altman plots. External rotation Mallet scores determined by motion capture and by the physician were compared. RESULTS: The measures of GH CBA were not statistically different and demonstrated good agreement, but substantial variation. For HT ER, all measures were significantly different and demonstrated poor agreement and substantial variation. When the joint angles measured by motion capture were used to determine the Mallet score, 79% of external rotation Mallet scores assigned by the physician were incorrectly categorized, with the physician always scoring the participant higher than predicted motion capture Mallet score. CONCLUSIONS: Both GH CBA and HT ER measures demonstrated substantial variability between measurement types, but only HT ER joint angles were significantly different. In addition, more than three-quarters of external rotation Mallet scores were misclassified by the physician. Motion capture measurements offer the benefit of less susceptibility to patients' compensatory and/or out-of-plane movements and should be considered for clinical assessment of shoulder range of motion in children with BPBI. If motion capture is unavailable, the use of a goniometer provides more accurate clinical measures of shoulder motion than visual estimates and care should be taken to minimize and account for compensatory movement strategies. LEVEL OF EVIDENCE: Level IV Case series.

Trunk Range of Motion and Patient Outcomes After Anterior Vertebral Body Tethering Versus Posterior Spinal Fusion: Comparison Using Computerized 3D Motion Capture Technology.

BACKGROUND: Anterior vertebral body tethering (AVBT) for adolescent idiopathic scoliosis (AIS) is postulated to preserve motion compared with traditional posterior spinal fusion (PSF), but few studies exist to date. We used a validated computerized 3D model to compare trunk motion between patients treated with PSF and AVBT, and analyzed trunk motion in relation to the lowest instrumented vertebra (LIV). METHODS: This was a single-center retrospective review of a consecutive series of skeletally immature patients with AIS who underwent motion analysis prior to PSF (n = 47) or AVBT (n = 65) and 2 years postoperatively. Patients were divided into 4 groups on the basis of the LIV (≤L1, L2, L3, L4). Computerized 3D kinematic evaluations included thoracic and lumbar flexion, extension, side-bending, and rotation. Patient outcomes were assessed using the Scoliosis Research Society (SRS)-22 questionnaire. RESULTS: The LIV was ≤L1 in 48 patients treated with AVBT and 23 treated with PSF, L2 in 4 AVBT and 8 PSF patients, L3 in 10 AVBT and 8 PSF patients, and L4 in 3 AVBT and 8 PSF patients. PSF patients had a significant loss of motion in all 4 directions at 2 years postoperatively (e.g., flexion loss was 11° for ≤L1 to 30° for L4; p < 0.001). This equated to a 7° loss of trunk flexion per additional LIV level included in the fusion. AVBT patients only demonstrated loss of flexion and side-bending at 2 years postoperatively (e.g., flexion loss of 11° for L1 to 17° for L4; p < 0.001). Preoperative curve size and flexibility did not have any significant impact on differences in trunk motion between AVBT and PSF. SRS-22 scores were predominantly similar for AVBT versus PSF preoperatively and at 2 years postoperatively. CONCLUSIONS: Patients treated with AVBT experienced predominantly less motion loss compared with PSF patients at 2 years postoperatively. Patients treated with PSF demonstrated loss of motion in all planes that increased with each additional LIV from ≤L1 to L4, with 7° loss of flexion per additional LIV. However, the differences in total trunk motions were relatively modest for PSF and AVBT with an LIV of ≤L1. Preoperative curve magnitude and flexibility had no significant impact on trunk motion in either group. SRS-22 scores were similar for both groups at 2 years postoperatively. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Reachable workspace with real-time motion capture feedback to quantify upper extremity function: A study on children with brachial plexus birth injury.

Clinical upper extremity (UE) functional assessments and motion capture measures are limited to a set of postures and/or motions that may provide an incomplete evaluation of UE functionality. Reachable workspace analysis offers a more global assessment of UE function, but is reliant on patient compliance with instructions and may result in underestimates of a patient's true UE function. This study evaluated a clinical tool that incorporates real-time visual feedback with motion capture to provide an innovative means of engaging patients to ensure a 'best effort' quantification of their available UE workspace. Reachable workspace for 10 children with brachial plexus birth injury was collected with and without real-time feedback on the affected and unaffected limbs. Real-time feedback consisted of subjects reaching for virtual targets surrounding their physical space using a virtual cursor controlled by the real-time location of their hand. Real-time feedback resulted in significantly greater workspace in multiple regions on both the affected (3/6 octants; mean differences 10.8%-20.0%) and unaffected (6/6 octants; mean differences 24.3%-40.0%) limbs. Use of real-time feedback also yielded significant interlimb differences in workspace across more regions (4/6 octants; mean differences 29.0%-39.9% vs. 1/6 octants; mean difference 17%). Finally, real-time feedback resulted in significant interlimb differences in median reach distance across more regions (4/6 octants; mean differences 7.5%-44.8% vs. 1/6 octants; mean difference 11.2%). A reachable workspace tool with real-time feedback results in more workspace and UE function recorded and offers a highly visual and intuitive depiction of a patient's UE abilities.

Limited evidence for graft selection in pediatric ACL reconstruction: a narrative review.

Anterior cruciate ligament reconstruction is the preferred treatment to anterior cruciate ligament injury. With the increase in anterior cruciate ligament injuries in both adults and skeletally immature patients comes the need for individualized anterior cruciate ligament reconstruction graft selection whether it is the type of graft (auto vs. allograft) or the harvesting site (hamstrings, iliotibial band, quadriceps, patella). Several factors need to be considered preoperatively in order to optimize the patients' recovery and restore anterior cruciate ligament strength and function. These include age and bone maturity, preoperative knee flexor/extensor strength, sport participation, patient's needs and anatomical characteristics. This paper aims at bringing evidence supporting the use of a personalized approach in graft selection for faster and more efficient return to sport and propose a theoretical framework to support the approach.

Scapulothoracic and Glenohumeral Contributions to Humerothoracic Kinematics in Single Versus Double Tendon Transfers in Patients With Brachial Plexus Birth Injury.

PURPOSE: Evidence suggests that patients with brachial plexus birth injury are more likely to retain midline function following a teres major tendon transfer without a concomitant latissimus dorsi transfer. Both procedures increase shoulder external rotation and abduction, but whether increased loss of midline frequency following double transfer is due to glenohumeral (GH) joint motion or scapulothoracic (ST) compensation is unknown. We hypothesized that double tendon transfers would exhibit greater GH external rotation than single tendon transfers, thus requiring greater ST rotation to internally rotate the shoulder, while GH and ST contributions to elevation remained equivalent between both groups. METHODS: Twenty-six postsurgical children with C5/C6 brachial plexus birth injuries participated in this study. Thirteen patients with single tendon transfers were matched with 13 with double tendon transfer. Coordinate systems of the thorax, scapula, and humerus were measured utilizing motion capture in 6 arm positions. Joint angles were calculated by the helical (ST) and modified globe method (GH and humerothoracic [HT]). Differences between groups were compared with repeated measures of multivariate analyses of variance for each position. Pending significant multivariate analyses of variance, univariate analyses of variance determined joint differences between transfer groups. RESULTS: Joint rotations from neutral were similar between groups in 5 of 6 tested positions, with double tendon transfers consistently demonstrating 15°-20˚ more internal rotation at the GH and HT joints. Still, only the internal rotation position showed statistically significant differences in GH and HT joint angles. The ST joint angles were similar in this position (45.2˚ and 48.5˚). CONCLUSIONS: The arc of motion for patients with double tendon transfer was more internally rotated than in patients with single tendon transfer at the GH and HT joints for all positions. However, both groups demonstrated little active rotation from neutral. Based on this data, teres major-only tendon transfers may not reduce the risk of loss of midline function. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Assessment of the relationship between Brachial Plexus Profile activity short form scores and modified Mallet scores.

INTRODUCTION: This study aims to assess the relationship between the modified Mallet classification and the Brachial Plexus Profile activity short form (BP-PRO activity SF). The therapist or surgeon classifies upper extremity movement for the modified Mallet classification, while the BP-PRO assesses parents' perceptions of difficulty performing activities. PURPOSE: To provide a deeper understanding of the relationship of functional and perceived outcome measurements. STUDY DESIGN: Prospective, correlational design. METHODS: Eighty children with brachial plexus birth injuries were evaluated using the modified Mallet classification, while parents simultaneously answered the BP-PRO activity SF questions. All patients had undergone one of three surgical interventions to improve shoulder function. The relationship between the two measures, patient injury levels, and surgical histories were assessed. RESULTS: The average modified Mallet scores and BP-PRO activity SF scores weakly correlated (r = 0.312, P = .005) and both measures differentiated between C5-6 and C5-7 injury levels (P = .03 and P = .02, respectively). Conversely, the modified Mallet scores could differentiate between the three surgical groups (F = 8.2, P < .001), while the BP-PRO activity SF could not (P = .54). CONCLUSION: The results suggest that these tools measure different aspects of patient outcomes. The Mallet classification may be more focused on shoulder motion than the BP-PRO activity SF. Additional questions that specifically require shoulder function could be incorporated into the BP-PRO activity SF to improve understanding of patient/parent perceptions of shoulder function for children with brachial plexus injuries. Clinicians should be aware of the strengths, weaknesses, and limitations of each outcome assessment tool for appropriate use and interpretation of results.

Stiff Landings, Core Stability, and Dynamic Knee Valgus: A Systematic Review on Documented Anterior Cruciate Ligament Ruptures in Male and Female Athletes.

Anterior cruciate ligament (ACL) injuries are the most common ligament injury of the knee, accounting for between 100,000 and 200,000 injuries among athletes per year. ACL injuries occur via contact and non-contact mechanisms, with the former being more common in males and the later being more common in females. These injuries typically require surgical repair and have relatively high re-rupture rates, resulting in a significant psychological burden for these individuals and long rehabilitation times. Numerous studies have attempted to determine risk factors for ACL rupture, including hormonal, biomechanical, and sport- and gender-specific factors. However, the incidence of ACL injuries continues to rise. Therefore, we performed a systematic review analyzing both ACL injury video analysis studies and studies on athletes who were pre-screened with eventual ACL injury. We investigated biomechanical mechanisms contributing to ACL injury and considered male and female differences. Factors such as hip angle and strength, knee movement, trunk stability, and ankle motion were considered to give a comprehensive, joint by joint analysis of injury risk and possible roles of prevention. Our review demonstrated that poor core stability, landing with heel strike, weak hip abduction strength, and increased knee valgus may contribute to increased ACL injury risk in young athletes.

Effect of Glenohumeral Reduction Type Combined With Tendon Transfer for Brachial Plexus Injury on Objective, Functional, and Patient-Reported Outcomes.

PURPOSE: Glenohumeral (GH) joint reductions are frequently performed during tendon transfer surgery for brachial plexus birth injuries (BPBI); however, the effect of reduction method (none required, closed, surgical) has not been assessed. This study compared objective, functional, and patient-reported outcomes between children who underwent a tendon transfer and (1) did not require GH reduction, (2) required concomitant closed GH reduction, or (3) required concomitant surgical GH reduction. METHODS: Fifty-four children with BPBI who previously underwent teres major and/or latissimus dorsi transfer with or without concomitant GH reduction participated. Joint reduction method was classified as none required (n = 21), closed (n = 9), or surgical (n = 24). Motion capture was collected in a neutral position, abduction, external rotation, and internal rotation. Glenohumeral joint angles and displacements were calculated. Joint angular displacements represented the differences between the joint angles in each terminal position and the joint angles of the arm at rest in the neutral position. A hand surgeon determined modified Mallet scores. Participants' parents completed the Brachial Plexus Profile Activity Short Form (BP-PRO-SF) to assess physical activity performance. RESULTS: The no-reduction group had significantly less GH elevation than the surgical-reduction group for all positions and significantly less GH elevation than the closed-reduction group for the neutral, external rotation, and internal rotation positions. There were no differences in GH rotation angles. Glenohumeral joint displacements from neutral and modified Mallet scores were similar. The no-reduction group demonstrated significantly greater BP-PRO-SF scores than the surgical-reduction group. CONCLUSIONS: Patients who underwent a closed or surgical GH joint reduction consistently displayed more GH elevation. Clinically, this corresponds to an abduction contracture. Whereas increased abduction contracture provided a benefit of greater overhead motion, modified Mallet scores were similar between groups. The surgical-reduction group demonstrated lower BP-PRO-SF outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Analysis of Shoulder Complex Function After Posterior Spinal Fusion in Adolescents With Idiopathic Scoliosis.

BACKGROUND: Nonsurgically treated patients with AIS demonstrate altered scapular kinematics and decreased patient-reported shoulder function compared with typically developing adolescents. It is unknown whether surgical correction of the spine deformity has beneficial or detrimental effects on scapulothoracic joint function, as previous assessments of shoulder function following surgery have only focused on humerothoracic motion. The objective of this study was to perform a comprehensive analysis of scapular kinematics before and after PSF and compare postoperative scapular kinematics in AIS to those of a typically developing cohort. METHODS: Typically developing adolescents (n=33) and patients with AIS (n=20) with a planned PSF surgery were recruited. Motion capture was used to analyze scapular kinematics at rest and in full abduction. AIS subjects were evaluated before surgery and at a 6-month follow-up. Individual changes following surgery were assessed, and postoperative scapular kinematics were compared with the typically developing subjects. RESULTS: Patients with AIS patients in this study demonstrated significant losses of scapulothoracic range of motion for the convex side shoulder and gains of scapulothoracic range of motion for the concave side shoulder following PSF. When compared with typically developing adolescents, the resting scapular position of the postoperative AIS group seemed normalized, but the AIS group still exhibited altered scapular motion, particularly along the upward rotation and tilt axes. CONCLUSIONS: Patients with AIS demonstrated significant changes at the scapulothoracic joint following PSF. Compared with typically developing adolescents, scapular resting position normalized, but the AIS group still demonstrated altered scapular kinematics, including patterns associated with shoulder pathology. The results of this study will inform the course of short-term postoperative rehabilitation by addressing the upper extremity implications of PSF for individuals with AIS. LEVEL OF EVIDENCE: Level III.

Scapular Stabilization Limits Glenohumeral Stretching in Children With Brachial Plexus Injuries.

PURPOSE: To quantify the effects of scapular stabilization on scapulothoracic and glenohumeral (GH) stretching. METHODS: Motion capture data during external rotation and abduction with and without scapular stabilization were collected and analyzed for 26 children with brachial plexus birth palsy. These positions were performed by an experienced occupational therapist and by the child's caretaker. Scapulothoracic and GH joint angular displacements were compared between stretches with no stabilization, stabilization performed by the therapist, and stabilization performed by the caretaker. The relationship between the age and ability of the therapist and caretaker to perform the stretches with scapular stabilization was also assessed. RESULTS: During external rotation there were no significant differences in either the scapulothoracic or GH joint during stabilization by either the therapist or the caretaker. During abduction, both scapulothoracic and GH joint angular displacements were statistically different. Scapulothoracic upward rotation angular displacement significantly decreased with scapular stabilization by the therapist and caretaker. Glenohumeral elevation angular displacement significantly decreased with scapular stabilization performed by the therapist and caretaker. There were only weak correlations between age and the differences in scapulothoracic and GH joint angular displacement performed by both the therapist and the caretaker. CONCLUSIONS: The findings of this study indicate that scapular stabilization may be detrimental to passive stretching of the GH joint in children, as demonstrated by a reduced stretch. Based on the findings of this study, we have changed our practice to recommend passive stretches without scapular stabilization for children aged 5 years and older with brachial plexus birth palsy. In infants and children aged less than 5 years, we now recommend stretching with and without scapular stabilization until the effect of scapular stabilization is objectively assessed in these age groups. LEVEL OF EVIDENCE/TYPE OF STUDY: Therapeutic IV.

Shoulder Complex Mechanics in Adolescent Idiopathic Scoliosis and Their Relation to Patient-perceived Function.

BACKGROUND: Proper contribution of the scapulothoracic joint is necessary for adequate shoulder complex function. Associations between trunk shape and abnormal scapular kinematics and subsequent shoulder dysfunction have been established; however, the extent of shoulder dysfunction in adolescent idiopathic scoliosis (AIS) is still poorly understood. The purpose of this study was to perform a comprehensive analysis of scapular kinematics during multiplanar arm motion in patients with AIS and compare kinematics and patient-reported function with that of a typically developing cohort. METHODS: Typically developing adolescents (n=33) and patients with AIS (n=26) with no history of spine or shoulder surgery were recruited for this study. A 3-dimensional optoelectronic motion capture system was used to analyze scapular kinematics in 4 positions: rest, full abduction, forward reach, and hand to spine. Subjects in each group also completed the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire as a measure of patient-reported function. RESULTS: The convex shoulders of the patients with AIS exhibited deficits in scapular upward rotation and posterior tilt in all positions and reduced protraction range of motion during reaching. The AIS group also reported worse patient-perceived shoulder function than the typically developing group; however, this dysfunction was not related to specific scapular kinematic patterns. CONCLUSIONS: Patients with AIS show alterations in scapular kinematics that are associated with shoulder pathology. Despite displaying an unaffected ability to place the hand in space, the underlying joint mechanics place these adolescents at risk for future pathology. Accordingly, consideration of scapulothoracic and glenohumeral joint function is warranted in the treatment of AIS. LEVEL OF EVIDENCE: Level III-cross-sectional comparison.