Personalized endoprostheses for the proximal humerus and scapulohumeral joint in dogs: Biomechanical study of the muscles' contributions during locomotion.

Osteosarcoma represents one of the most common bone tumours in dogs. It commonly occurs in the proximal humerus, the most affected anatomic site. Until recently, amputation or limb-sparing surgery leading to an arthrodesis coupled with chemotherapy were the only available treatments, but they often lead to complications, reduced mobility and highly impact dog's quality of life. Prototypes of both articulated and monobloc (no mobility) patient-specific endoprostheses have been designed to spare the limb afflicted with osteosarcoma of the proximal humerus. This study focuses on the biomechanical effects of endoprostheses and shoulder muscle kinematics. For each of the endoprosthesis designs, a minimal number of muscles needed to ensure stability and a certain degree of joint movement during walking is sought. A quasi-static study based on an optimization method, the minimization of the sum of maximal muscle stresses, was carried out to assess the contribution of each muscle to the shoulder function. The identification of the most important muscles and their impact on the kinematics of the prosthetic joint lead to an improvement of the endoprosthesis design relevance and implantation feasibility.

Comparison of ultrasound with electrodiagnosis of scapular winging: A prospective case control study.

OBJECTIVE: Compare high-resolution ultrasound (HRUS) and electrodiagnostic examination (EDX) in the diagnostic workup of patients with scapulae alatae. METHODS: 27 patients with scapulae alatae and 41 healthy subjects (HS) and underwent a standardized clinical examination (CEX), EDX and HRUS. We measured the thickness of the serratus anterior (SER), rhomboid major and trapezius muscles and the diameter of the long thoracic (LTN), dorsal scapular and spinal accessory nerves (SAN). RESULTS: Twenty patients showed medial winging and six patients showed lateral winging on CEX. One patient had both lateral and medial winging. In patients with medial winging, the SER muscle was thinner and the LTN diameter was larger on the symptomatic side compared with the asymptomatic side and with the dominant side in HS. In this group, both EDX and HRUS detected abnormalities of SER muscle/ LTN with sensitivity of 65%, and with specificity of 100% and 57%, respectively. EDX and HRUS detected abnormalities of the trapezius muscle/ SAN with sensitivity of 60% and 40%, and specificity of 91%, and 86 % a, respectively. There was no significant difference between the two methods. CONCLUSION: HRUS can contribute to the diagnostic workup of scapulae alatae by demonstrating atrophy of muscles and enlargement in nerve diameter. SIGNIFICANCE: HRUS supplements EDX in the diagnostic workup of scapulae alatae.

A Clinical Evaluation of Scapular Dyskinesis Among Professional Bus Drivers With Unilateral Upper Quadrant Musculoskeletal Pain.

BACKGROUND: Professional bus drivers report a high prevalence of upper quadrant musculoskeletal pain which could be associated with scapular dyskinesis (SD). However, the evidence for valid and reliable screening methods for this condition is limited as SD among bus drivers is an emerging area of research. Therefore, the main aim of the study was to investigate the reliability of dynamic scapular motion test (DSMT) using video analysis as an accurate method to evaluate SD and to identify patterns of SD among bus drivers. METHODS: In total, 32 bus drivers from a private bus company with unilateral upper quadrant musculoskeletal pain participated in the study. The DSMT was conducted and the SD was captured in the video during shoulder flexion-abduction movements. Two investigators analyzed the video recordings and identified the patterns of SD. The intra- and interrater reliability were determined using the percentage of agreement and weighted Kappa coefficients (Kw). Descriptive analysis was used to examine the patterns of SD. FINDINGS: The intra- and interrater reliability of DSMT using video analysis were excellent (Kw coefficient: 0.762-0.878 and 0.87-1.00, respectively). About 56.2% and 53.1% of bus drivers presented SD with the shoulder flexion and abduction movements during DSMT. Medial border prominence (Type II pattern of SD) was identified as the common pattern of SD. CONCLUSION/APPLICATION TO PRACTICE: The DSMT using video analysis showed excellent intra- and interrater reliability to evaluate SD. Occupational health practitioners can consider DSMT using video analysis to identify SD among people with upper quadrant musculoskeletal pain at the workplace.

Scapular dyskinesis: the origo of shoulder lesions? / Scapuladyskinesis: a vállelváltozások origója?

Összefoglaló. Bevezetés: A megváltozott statikus és/vagy dinamikus lapockapozíciót, azaz a scapuladyskinesist gyakran vonják párhuzamba a vállelváltozásokkal. Mindemellett a lapocka kinematikai eltérései nagy számban jelen lehetnek tünetmentes egyéneknél is, melegágyat biztosítva a késobbi vállelváltozások kialakulásának. Célkituzés: Munkánk fo célja az volt, hogy felhívja a figyelmet ezen problémakör fontosságára, valamint hogy megvizsgálja a scapuladyskinesis elofordulásának gyakoriságát és körülményeit az átlagpopulációban. Módszer: Mintánk 70 fobol állt (átlagéletkor: 22,17 ± 1,77 év). 67%-uk férfi, míg 33%-uk no volt. A scapuladyskinesis fennállását McClure-féle 'Scapular Dyskinesis Test'-tel vizsgáltuk. A résztvevok vállfájdalmának intenzitását vizuális analóg skála segítségével, habituális testtartásukat fotogrammetriás módszerrel, fobb lapockastabilizáló izmaik izomerejét pedig Kendall-féle manuális izomerotesztekkel mértük fel. Mindemellett felvettük antropometriai adataikat, valamint megkérdeztük, hogy milyen gyakran végeznek sporttevékenységet. Eredmények: A résztvevok 53%-ánál találtunk valamilyen fokú scapuladyskinesist. A habituális testtartást vizsgáló fotogrammetriás felmérés eredményei és a scapuladyskinesist méro McClure-féle teszt eredményei között szignifikáns összefüggést találtunk (p = 0,01). A sportolási gyakoriság és a scapuladyskinesis elofordulása között jelentos összefüggést tapasztaltunk (p = 0,01). A fájdalom erossége és a scapuladyskinesis elofordulása között szignifikáns volt az összefüggés (p = 0,03). A scapuladyskinesist méro McClure-féle teszt és az azonos oldali felso végtagon izomero-csökkenést mutató tesztek eredményei között szintén szignifikáns összefüggést tapasztaltunk (p = 0,01). Következtetés: Az elit sportolók mellett az átlagos populációban is jelentos mértékben jelen lehetnek a lapocka kinematikai eltérései. Mindez jelentos összefüggésben állhat az adott személy életmódjával és egészségmagatartásával, valamint kiemelt szerepet játszhat a krónikus vállfájdalom kialakulásában. Orv Hetil. 2021; 162(15): 587-594. INTRODUCTION: The altered static and/or dynamic scapular position, i. e., scapular dyskinesis, is often paralleled with shoulder pathologies. However, shoulder kinematic abnormalities may also be present in large numbers in asymptomatic individuals. OBJECTIVE: The main goal of our work was to draw attention to the importance of scapular dyskinesis in shoulder pathologies. METHOD: The final sample consisted of 70 people (average age: 22.17 ± 1.77 years), 67% of them was male and 33% female. The presence of scapular dyskinesis was assessed by McClure's Scapular Dyskinesis Test. Visual analog scale was used to examine the shoulder pain of the participants, photogrammetric method was used to document their habitual posture. Kendall's manual muscle testing methods were used to determine the muscle strength of the individual muscles of the shoulder girdle; we also recorded their anthropometric data and asked them about their sporting habits. RESULTS: In 53% of the participants, some degree of scapular dyskinesis was found. We observed significant correlation between the sporting habits and scapular dyskinesis (p = 0.01). Significant correlation was observed between the posture and scapular dyskinesis (p = 0.01). Between the strength of pain and the dyskinesis, we found a significant correlation (p = 0.03). There was a significant correlation between the results of the McClure's test and the tests showing muscle strength loss around the scapula (p = 0.01). CONCLUSION: In addition to elite athletes, scapular dyskinesis may also be significantly present in the average population and can play a key role in the development of shoulder pain. Orv Hetil. 2021; 162(15): 587-594.

Shoulder function after constraint-induced movement therapy assessed with 3D kinematics and clinical and patient reported outcomes: A prospective cohort study.

INTRODUCTION: We hypothesised that reduced shoulder function post stroke improves during constraint-induced movement therapy and that improvement in scapula upward rotation measured with three-dimensional kinematics is associated with improvements in clinical and patient reported outcomes. METHODS: Thirty-seven patients were tested pre and post constraint-induced movement therapy and again at three-month follow-up. Kinematic outcome measures - with scapula upward rotation as the primary outcome - during tasks 5 (ReachLow) and 6 (ReachHigh) from the Wolf Motor Function Test were included together with clinical and patient reported outcomes. Changes in outcome measures were analysed with linear mixed models and logistic regression analysis. FINDINGS: Scapula upward rotation was reduced from 16.2° pre intervention through 15.9° post intervention to 15.6° at three-month follow-up during ReachHigh. Statistically significant reductions of <2° were also found for shoulder flexion during ReachLow and trunk lateral flexion during ReachHigh. The clinical and patient reported outcomes showed improvements post constraint-induced movement therapy, and at follow-up, the outcomes resembled post values. INTERPRETATION: The minimal improvements in selected 3D kinematic measures of upper extremity movements did not reflect any clinically meaningful changes. Therefore, the clinical and patient reported improvements could not be related to restitution of shoulder function.

Discriminating the precision of inertial sensors between healthy and damaged shoulders during scaption movement: A cross-sectional study.

BACKGROUND: Shoulder assessment in rehabilitation is focused on kinematic properties due to the variability of symptomatology and clinical expression of shoulder injuries. AIM: To perform a receiver operating characteristic analysis of the kinematic variables involved in the functional mobility of the shoulder that allow the identification of discriminating variables between healthy and diseased shoulders during scaption motion. METHOD: Analytical cross-sectional study of diagnostic effectiveness was performed in 27 subjects suffering from shoulder damage and 14 asymptomatic controls. Scaption kinematics were evaluated using four inertial sensors placed on the humerus, scapula, forearm and sternum. Three variables (mobility, velocity and acceleration) were obtained from each sensor and the norm of the resultant vector was calculated from each axis. A discriminatory receiver operating characteristic analysis was performed, obtaining the area under the curve, sensitivity and specificity. FINDINGS: Significant differences from both the resultant vectors and the axis depended on the body segment analysed were observed. Greater movement velocity and acceleration were observed in the asymptomatic group. Receiver operating characteristic analysis, scapular protraction-retraction mobility distinguished with a diagnostic sensitivity of 83.3% and specificity of 90.9% between asymptomatic and shoulder-damaged patients. These diagnosis values were 83.3% and 72.7% for scapular anterior-posterior velocity. Scapular kinematics, in terms of mobility and velocity, are the key variables in shoulder assessment. INTERPRETATION: This study discriminated between patients suffering from shoulder damage and asymptomatic subjects based on shoulder kinematics during scaption motion. Scapular mobility and velocity were found to be key variables in shoulder assessment, along with the humerus.

A computer tablet software can quantify the deviation of scapula medial border from the thoracic wall during clinical assessment of scapula dyskinesis.

PURPOSE: Aim of this study is to establish an objective and easily applicable method that will allow clinicians to quantitatively assess scapular dyskinesis during clinical examination using a computer tablet software. Hypothesis is that dyskinetic scapulae present greater motion-deviation from the thoracic wall-compared to the non-dyskinetic ones and that the software will be able to record those differences. METHODS: Twenty-five patients and 19 healthy individuals were clinically evaluated for the presence of dyskinesis or not. According to the clinical diagnosis, the observations were divided into three groups; A. Dyskinetic scapulae with symptoms (n = 25), B. Contralateral non-dyskinetic scapulae without symptoms (n = 25), C. Healthy control scapulae (n = 38). Then, all individuals were tested using a tablet with the PIVOT™ image-based analysis software (PIVOT, Impellia, Pittsburgh, PA, USA). The motion produced by the scapula medial border and inferior angle deviation from the thoracic wall was recorded. RESULTS: The deviation of the medial border and inferior angle of the scapula from the thoracic wall was 24.6 ± 7.3 mm in Group A, 14.7 ± 4.9 mm in Group B, and 12.4 ± 5.2 mm in Group C. The motion recorded in the dyskinetic scapulae group was significantly greater than both the contralateral non-dyskinetic scapulae group (p < 0.01) and the healthy control scapulae group (p < 0.01). CONCLUSION: The PIVOT™ software was efficient to detect significant differences in the motion between dyskinetic and non-dyskinetic scapulae. This system can support the clinical diagnosis of dyskinesis with a numeric value, which not only contributes to scapula dyskinesis grading but also to the evaluation of the progress and efficacy of the applied treatment, thus providing a feedback to the clinician and the patient. LEVEL OF EVIDENCE: IV, laboratory study.

Feedback improves the scapular-focused treatment effects in patients with shoulder impingement syndrome.

PURPOSE: This study aimed to evaluate the effects of scapular-focused treatment with (SFTF) and without (SFT) feedback on pain, function, and scapular kinematics in patients with Shoulder Impingement Syndrome (SIS). METHODS: Seventy-five males and females with SIS were randomly assigned into SFTF (n = 25), SFT (n = 25) and control (n = 25) groups. The primary outcome was pain, assessed by Visual Analog Scale (VAS). The secondary outcomes were function and scapular kinematics, assessed by DASH Questionnaire and a 3-D motion capture, respectively. All outcomes were measured at the baseline and after the 8-week interventions. RESULTS: A post hoc analysis performed to show significant differences between groups after the 8-week interventions. For pain, there were significant differences between SFTF vs. SFT (ES (95% CI) = - 0.3(- 0.4 to - 0.1); P = 0.04), SFTF vs. control (ES (95% CI) = 1.3(0.7-1.9); P = 0.01). For DASH, also, there were significant differences between SFTF vs. SFT (ES (95% CI) = 1.8(1.1-2.4); P = 0.03), SFTF vs. control (ES (95% CI) = 4.4(3.3-5.4); P = 0.01), and SFT vs. control (ES (95% CI) = 2.6(1.8-3.4); P = 0.01). For scapular internal rotation (the sagittal or scapular planes), scapular upward rotation, and the scapular tilt, however, there were no differences between SFTF vs. SFT. CONCLUSION: Based on the study results, a rehabilitation program integrated with verbal feedbacks is effective to relieve pain, and improve function and scapular kinematics in patients with SIS. Adding feedback to an exercise therapy could clinically enhance outcomes in patients with SIS. LEVEL OF EVIDENCE: Level II. TRIAL REGISTRATION: This study was prospectively registered at UMIN-CTR website, and the unique trail number is UMIN000036399.

The critical shoulder angle, the acromial index, the glenoid version angle and the acromial angulation are associated with rotator cuff tears.

PURPOSE: To compare the critical shoulder angle (CSA), acromion index (AI), acromion angulation (AA) and glenoid version angle (GVA) between patients with full-thickness rotator cuff tears (RCTs) and patients with intact rotator cuffs. METHODS: Between 2014 and 2018, the CSA, AI, AA and GVA were measured in consecutively included patients aged > 40 years who underwent shoulder arthroscopy for full-thickness RCTs. A total of 437 patients with RCTs and a mean age of 51.2 years (± 5.8) were included, 35.7% of whom were male. In the control group, there were n = 433 patients (36.3% male) with an intact rotator cuff, and the mean age was 50.7 years (± 5.3). RESULTS: The mean AI for the RCT group was 0.7 ± 0.1, which was significantly higher than the mean AI for the control group (0.6 ± 0.1, p < 0.001). The mean CSA for the RCT group was 33.6° ± 3.9°, which was significantly higher than the mean CSA for the control group (31.5° ± 4°, p < 0.001). The mean AA for the RCT group was 13.9° ± 9°, which was significantly higher than the mean AA for the control group (12.4 ± 8.6, p = 0.012). The mean GVA for the RCT group was - 3.5° ± 4.6° and significantly retroverted compared with the mean GVA for the control group (- 2.2° ± 4.6°, p < 0.001). The cutoff values determined by the ROC curve analyses were as follows: 0.6 for AI, 31.4° for CSA, 9.6° for AA and - 2.6° for GVA. CONCLUSION: The CSA, AI, GVA and AA values measured by MRI were determined to be significantly related to full-thickness rotator cuff ruptures. The AI, CSA, AA and GVA may be considered risk factors for degenerative rotator cuff tears. Assessing the CSA, AI, GVA and AA can be helpful for diagnostic evaluation of patients with full-thickness RCTs. LEVEL OF EVIDENCE: III.

Tight shoulders: A clinical, kinematic and strength comparison of symptomatic and asymptomatic male overhead athletes before and after stretching.

A tightness of the posterior structures of the throwing shoulder has been hypothesised to be associated with injuries and pain because of alterations of the scapular kinematics and muscular imbalances. The aims of this study were to identify the clinical and biomechanical profile of symptomatic and asymptomatic overhead athletes with a tight shoulder and to evaluate the efficiency of a self-applied stretching program. Twenty male overhead athletes were recruited. Half of them reported a painful shoulder at the beginning of the study. For four weeks, the volunteers performed daily stretching exercises. Before and after the stretching program, gleno-humeral mobility, scapular kinematics, rotator muscles strength and pain were evaluated. Before stretching, the main difference between the groups was more impingement syndrome and rotator cuff tendon lesion positive tests in the symptomatic group (p < 0.027, effect size = 0.51). After the program, pain reported by the symptomatic volunteers was reduced by approximately 40% and the gleno-humeral internal rotation bilateral difference was significantly reduced by 77.6% (p < 0.009, effect size = 0.84). In the symptomatic group, the scapula at rest was significantly more posteriorly tilted (p = 0.027, effect size = 0.69) after the stretching; a position that has been shown to limit the risk of impingement. The absence of significant differences of the profiles of the symptomatic and asymptomatic overhead athletes before stretching may indicate that the initiation of early prevention programs, including self-applied stretching, should not rely solely on biomechanical and clinical parameters and might be recommended to all players with a tight shoulder.

Recruitment of Shoulder Complex and Torso Stabilizer Muscles With Rowing Exercises Using a Suspension Strap Training System.

BACKGROUND: Suspension training systems, which use body weight resistance under unstable conditions, may be effective for muscle strengthening in persons with scapular dyskinesis or subacromial impingement syndrome. HYPOTHESIS: Greater arm, scapular, and trunk muscle recruitment will occur during horizontal abduction row exercises. STUDY DESIGN: Descriptive laboratory study. LEVEL OF EVIDENCE: Level 5. METHODS: Surface electromyography data were collected from 28 participants (14 men, 14 women). A total of 13 right-sided muscles were studied at a sampling frequency of 1000 Hz. Maximal voluntary isometric contractions (MVICs) were established. Participants completed 3 repetitions per exercise in random order. We compared muscle recruitment during 3 rowing exercises: low row, high row, and horizontal abduction row. Data were compared with repeated-measures analyses of variance and post hoc Bonferroni corrections. RESULTS: For high row and horizontal abduction row conditions, the upper, middle, and lower trapezius and posterior deltoid demonstrated >60% MVIC magnitudes of recruitment, and the upper erector spinae demonstrated 40% to 60% MVIC magnitudes of recruitment, respectively. In contrast, in the low row exercise, 40% to 60% MVIC magnitudes of recruitment were observed only in the middle trapezius, latissimus dorsi, and posterior deltoid. CONCLUSION: With the suspension system, high row and horizontal abduction row exercises promote muscle strengthening (>50% MVIC) in the upper, middle, and lower fibers of the trapezius, posterior deltoid, and upper erector spinae. CLINICAL RELEVANCE: Rowing exercises performed with suspension straps may be recommended for muscle strengthening in patients with scapular dyskinesis and subacromial impingement syndrome as well as for healthy persons in need of enhanced scapular muscle performance.

Validity of Clinical Measurement Instruments Assessing Scapular Function: Insufficient Evidence to Recommend Any Instrument for Assessing Scapular Posture, Movement, and Dysfunction-A Systematic Review.

OBJECTIVE: To determine the construct validity, criterion validity, and responsiveness of measurement instruments evaluating scapular function. DESIGN: Systematic review of measurement properties. LITERATURE SEARCH: The MEDLINE, Embase, CINAHL, and SPORTDiscus databases were systematically searched from inception until March 2019. STUDY SELECTION CRITERIA: Studies published in Dutch, English, or German were included when they evaluated at least 1 of the measurement properties of interest. No restrictions were made regarding participants' health status. DATA SYNTHESIS: Two reviewers independently evaluated study quality using the COSMIN checklist and extracted and analyzed data. Quality of evidence was graded by measurement property for each distinctive type of measurement. RESULTS: Thirty-one measurement instruments in 14 studies were categorized into instruments to measure scapular posture and movement, and to assess scapular dyskinesis. Quality of evidence was at most moderate for 4 instruments with respect to criterion validity. Of these, criterion validity for instruments measuring scapular protraction/retraction posture and rotation angles up to 120° of thoracohumeral elevation was sufficient. Criterion validity for instruments measuring asymmetrical scapular posture, range of motion, and the lateral scapular slide test was insufficient. Quality of evidence for measurement properties of all other instruments was graded lower. CONCLUSION: There is currently insufficient evidence to recommend any instrument for the clinical examination of scapular function. Measurement instruments to assess scapular dyskinesis are prone to misinterpretation and should therefore not be used as such. J Orthop Sports Phys Ther 2020;50(11):632-641. doi:10.2519/jospt.2020.9265.

Reliability of assessment methods for scapular dyskinesis in asymptomatic subjects: A systematic review.

OBJECTIVE: The aim of this systematic review was to evaluate the available published evidence on the intra- and inter-rater reliabilities of assessment methods used for identifying and measuring scapular dyskinesis (SD) in asymptomatic subjects. METHODS: A systematic electronic literature search was performed in PubMed, Physiotherapy Evidence Database, Scopus, and the Cochrane Library, and studies on the intra- and inter-rater reliabilities of physical examination tests used for identifying SD in asymptomatic people were identified. Methodological quality of the studies meeting the inclusion criteria was assessed using the Quality Appraisal of Reliability Studies (QAREL) checklist by two reviewers. The overall level of evidence of this systematic review was determined by the Modified Cochrane Back Pain Criteria based on previous research which was modified for reliability studies of the shoulder complex. RESULTS: The literature search generated 388 results, and only 14 articles met the inclusion criteria. In these studies, reliabilities of two qualitative and five quantitative methods for the assessment of SD were analyzed. The QAREL checklist revealed that 12 studies had moderate risk of bias and 2 had high risk of bias. Additionally, none of the studies were of high quality. On the basis of the Modified Cochrane Back Pain Criteria, the overall level of evidence was moderate. Most of the studies including quantitative measurement methods found good to excellent inter- and intra-rater reliability values. Most of the studies including qualitative methods found low-to-moderate intra- and inter-rater reliability values. CONCLUSION: Considering the available published evidence, there is lack of high-quality studies evaluating the inter- and intra-rater reliabilities of qualitative or quantitative methods used for the assessment of SD. There are no qualitative methods with high reliability that are fit for clinical applications. Some quantitative methods with higher reliability are present, but clinicians should be aware of the methodological flaws that studies evaluating these methods suffer from. LEVEL OF EVIDENCE: Level II, Diagnostic study.

Influence of Scapula Training Exercises on Shoulder Joint Function After Surgery for Rotator Cuff Injury.

BACKGROUND The aim of this study was to assess the clinical effectiveness of scapula training exercises on shoulder function after surgery for rotator cuff injury. MATERIAL AND METHODS Forty-six patients with rotator cuff injury after surgery were randomized into the experiment group or control group. Both groups were treated with conventional therapeutic exercise and physical therapy, and scapular training exercise was added to the experiment group. Patient status was evaluated by Constant-Murley scale (CMS), visual analogue scale (VAS), and the active range of motion (ROM) of the shoulder before and after 6 weeks and 12 weeks of treatment. RESULTS After 6 weeks and 12 weeks of treatment, all evaluations of the 2 groups were significantly improved as compared with those before treatment (P0.05). After 12 weeks of treatment, all items in the experimental group were significantly improved compared to the control group (P<0.05). CONCLUSIONS The combination of conventional rehabilitation interventions and scapular training exercise were an effective treatment of the shoulder dysfunction. Moreover, increased Scapula training exercise had better effect on the improvement of shoulder function.

Shoulder pain and scapular dyskinesis associated with lower trapezius dysplasia - A case report.

BACKGROUND: Scapular dyskinesis (SD) has been associated with shoulder soft-tissue tightness as well scapular muscle strength and/or activation deficits. Inadequate development of the trapezius muscle (trapezius dysplasia) is a relatively rare condition inconsistently associated with shoulder dysfunction. CASE DESCRIPTION: a 24-year old male complaining of left scapular area pain associated with SD and scapular muscle weakness was noted to present with a smaller ipsilateral lower trapezius (LT). Further inquiry including electromyography, rehabilitative ultrasound imaging (RUSI) and magnetic resonance imaging ruled out nerve palsy and demonstrated a hypoplastic left LT. This led to a greater emphasis on serratus anterior (SA) training along with the addition of neuromuscular electrical stimulation of the LT. OUTCOMES: Following 12 sessions over a 5-month period the patient reported no pain or functional deficits, and was able to resume all recreational activities. The patient's subjective shoulder value increased from 55% to 80%, and LT strength was markedly improved. DISCUSSION: Scapular muscle dysplasia may represent a less recognized cause of SD. A more thorough inspection of scapular muscle shape and orientation, possibly augmented by RUSI may be indicated in patients presenting with SD. Neuromuscular electrical stimulation is a potentially useful modality for addressing scapular muscle activation and strength deficits and future research into its efficacy under these circumstances may be warranted.

A cadaveric morphometric analysis of coracoid process with reference to the Latarjet procedure using the "congruent arc technique".

INTRODUCTION: Congruent arc Latarjet procedure involves rotating the coracoid process so that its inferior surface is flush with the glenoid face, owing to their matching radius of curvature (ROC). However, there has been no cadaveric study to actually measure and compare the ROC of coracoid with glenoid, especially in Indian population. MATERIALS AND METHODS: 44 shoulders were dissected in 24 cadavers to measure usable length of coracoid process, width, height, ROC of coracoid and glenoid as well as ulnar length (as proxy of cadaver height). Critical coracoid height and length were estimated based on screw sizes of 2.7 mm, 3.5 mm, 4 mm and 4.5 mm, and pair concordance between height and length calculated. ROC of coracoid and glenoid were compared to measure extent of congruency. RESULTS: The mean usable length of coracoid process, width and height at mid-point were 21.8 mm, 13.7 mm and 8.6 mm, respectively. Out of the different screw sizes, 2.7 mm screws were found safe in 82% shoulders. 24 coracoid-glenoid pairs fulfilled the operational definition (≤ 5 mm) of congruency while rest 20 were seemingly incongruent chiefly due to coracoid variations, with mean ROC difference 4.13 mm (95% CI 1.51-6.74 mm). The ulnar length was significantly smaller in the incongruent ROC group (p = 0.0002). CONCLUSIONS: The available length as well as height of the transferred coracoid must be considered when deciding optimum diameter fixation screws in Latarjet procedure. Owing to smaller anatomic dimensions of coracoid in Indian population, 2.7-mm screws provide the safest fixation option. Also, the ROC of coracoid and glenoid does not match in substantial proportion of the cadavers. Pre-operative planning should include a CT-based assessment of glenoid and coracoid dimensions to decide the technique of Latarjet procedure and the optimum diameter fixation screws required.

Association of Both Scapular Upward Rotation and Scapulothoracic Muscle Lengths With Shoulder Pain, Function, and Range of Movement.

OBJECTIVE: Our aim was to analyze whether shoulder pain is related to scapular upward rotation (SUR) or to the lengths of the pectoralis minor and levator scapulae muscles. METHODS: This cross-sectional, observational study was carried out in 3 primary-care centers; 54 individuals with chronic shoulder pain participated. Scapular upward rotation and the lengths of the pectoralis minor and levator scapulae muscles were assessed. RESULTS: The level of association was small between shoulder pain and function and (1) the lengths of the pectoralis minor (r = 0.08, P = .93) and levator scapulae (r = -0.01, P = .57) muscles and (2) SUR at 45° (r = 0.17, P = .21), 90° (r = 0.08, P = .57), and 135° (r = 0.10, P = 0.45) of shoulder elevation. CONCLUSION: The relationship was small between shoulder pain and function and (1) SUR (45°, 90°, and 135° of shoulder elevation) and (2) the lengths of the pectoralis minor and levator scapulae muscles. Thus, the use of SUR and pectoralis minor and levator scapulae lengths in shoulder assessment should be undertaken with caution. Other factors such as psychological factors, central/peripheral sensitization, and intrinsic properties of the tissue have to be taken into account.

Reliable interpretation of scapular kinematics depends on coordinate system definition.

BACKGROUND: Interpretation of shoulder motion across studies has been complicated due to the use of numerous scapular coordinate systems in the literature. Currently, there are no simple means by which to compare scapular kinematics between coordinate system definitions when data from only one coordinate system is known. RESEARCH QUESTION: How do scapular kinematics vary based on the choice of coordinate system and can average rotation matrices be used to accurately convert kinematics between scapular local coordinate systems? METHODS: Average rotation matrices derived from anatomic landmarks of 51 cadaver scapulae (29 M/22 F; 59 ±â€¯13 yrs; 26R/25 L; 171 ±â€¯11 cm; 70 ±â€¯19 kg; 23.7 ±â€¯5.5 kg/m2) were generated between three common scapular coordinate systems. Absolute angle of rotation was used to determine if anatomical variability within the cadaver population influenced the matrices. To quantify the predictive capability to convert kinematics between the three coordinate systems, the average rotation matrices were applied to scapulothoracic motion data collected from 19 human subjects (10 M/9 F; 43 ±â€¯17 yrs; 19R; 173 ±â€¯9 cm; 71 ±â€¯16 kg; 23.6 ±â€¯4.5 kg/m2) using biplane fluoroscopy. Root mean squared error (RMSE) was used to compare kinematics from an original coordinate system to the kinematics expressed in each alternative coordinate system. RESULTS: The choice of scapular coordinate system resulted in mean differences in scapulothoracic rotation of up to 23°, with overall different shapes and/or magnitudes of the curves. A single average rotation matrix between any two coordinate systems achieved accurate conversion of scapulothoracic kinematics to within 4° of RMSE of the known solution. The average rotation matrices were independent of sex, side, decomposition sequence, and motion. SIGNIFICANCE: Scapulothoracic kinematic representations vary in shape and magnitude based solely on the choice of local coordinate system. The results of this study enhance interpretability and reproducibility in expressing scapulothoracic motion data between laboratories by providing a simple means to convert data between common coordinate systems. This is necessitated by the variety of available motion analysis techniques and their respective scapular landmark definitions.

Risk Factors of Overuse Shoulder Injuries in Overhead Athletes: A Systematic Review.

CONTEXT: Shoulder injuries are highly prevalent in sports involving the upper extremity. Some risk factors have been identified in the literature, but consensus is still lacking. OBJECTIVES: To identify risk factors of overuse shoulder injury in overhead athletes, as described in the literature. DATA SOURCES: A systematic review of the literature from the years 1970 to 2018 was performed using 2 electronic databases: PubMed and Scopus. STUDY SELECTION: Prospective studies, written in English, that described at least 1 risk factor associated with overuse shoulder injuries in overhead sports (volleyball, handball, basketball, swimming, water polo, badminton, baseball, and tennis) were considered for analysis. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Data were extracted from 25 studies. Study methodology quality was evaluated using the Modified Coleman Methodology Score. RESULTS: Intrinsic factors, previous injury, range of motion (lack or excess), and rotator cuff weakness (isometric and isokinetic) highly increase the risk of future injuries. Additionally, years of athletic practice, body mass index, sex, age, and level of play seem to have modest influence. As for the effect of scapular dysfunction on shoulder injuries, it is still controversial, though these are typically linked. Extrinsic factors, field position, condition of practice (match/training), time of season, and training load also have influence on the occurrence of shoulder injuries. CONCLUSION: Range of motion, rotator cuff muscle weakness, and training load are important modifiable factors associated with shoulder injuries. Scapular dysfunction may also have influence. The preventive approach for shoulder injury should focus on these factors.

Injury Mechanism of Acute Anterior Shoulder Dislocation Associated with Glenoid and Greater Tuberosity Fractures: A Study Based on Fracture Morphology.

OBJECTIVE: Based on the morphological characteristics of glenoid and greater tuberosity (GT) fractures and the relationship between them, we explored the injury mechanism of acute anterior shoulder dislocation associated with glenoid and GT fractures. METHODS: From December 2013 to December 2019, we retrospectively reviewed the clinical data of patients who were diagnosed with acute anterior shoulder dislocation associated with glenoid and GT fractures in our hospital. According to the fracture site, a glenoid fracture group and a greater tuberosity fracture (GT) group were established, and the morphological characteristics of both glenoid and GT fractures were measured and statistically analyzed. RESULTS: A total of 41 patients (43 shoulders) met the inclusion criteria (39 unilateral shoulders and 2 bilateral shoulders). The mean age was 50.21 years (range, 22-71 years). A total of 27 shoulder injuries (62.8%) were split GT fractures and 33 shoulder injuries (76.7%) were combined with rotator cuff tears. The mean size of glenoid fragments was 30.16% and the mean displacement was 8.85 mm. The mean size of GT fragments was 28.43 mm. The mean superoinferior and anteroposterior displacements of the GT fragment were 6.77 mm and 4.96 mm, respectively. There was a negative correlation between the size of glenoid and GT fracture fragments (r = -0.64, P < 0.05). The glenoid fragments in the Ideberg type Ia glenoid fracture group were smaller than those in the Ideberg type II glenoid fracture group (28.41% and 40.95%, respectively), while the size of GT fragments in the type Ia group were larger than those in the type II group (29.77 mm and 20.21 mm, respectively) (P < 0.05). The GT fragments in the split GT fracture group were larger than those in the avulsion or depression GT fracture group (33.69 mm, 19.07 mm and 21.12 mm, respectively), while the size of glenoid fragments in the split GT fracture group were smaller than those in the avulsion or depression GT fracture group (23.57%, 41.37%, and 43.42%, respectively) (P < 0.05). As for the displacement direction of GT fragments, depression fractures were mainly inferior displacements, avulsion fractures were mainly anterosuperior displacements, while split fractures were mainly posteroinferior displacements (P < 0.05). Multiple regression analysis suggested that the type and the fragment size of GT fractures have a significant influence on the size of glenoid fragments. CONCLUSION: Acute anterior shoulder dislocations associated with glenoid and GT fractures are often combined with rotator cuff tears. There is a negative correlation between the size of glenoid and GT fragments, and split GT fractures are most common. Such injuries are highly correlated to the relative spatial location between the GT and the glenoid when the shoulder dislocates.