Scapular positioning and movement in unimpaired shoulders, shoulder impingement syndrome, and glenohumeral instability

Three-dimensional scapular kinematics during commonly used rehabilitation exercises in patients 12 weeks after reverse shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (rTSA) is often used to restore functionality in patients with joint arthropathy and dysfunctional rotator cuff. As rTSA changes the biomechanical properties of the shoulder, an altered movement pattern of the arm and scapula is to be expected. Previous studies focused on changes of the scapulohumeral rhythm during functional elevation tasks. To our knowledge, no study exists examining scapular kinematics during rehabilitation exercises in a patient population with rTSA. Therefore, this study aimed to analyze 3-dimensional scapular kinematics during 3 commonly used rehabilitation exercises 12 weeks after rTSA surgery. It was hypothesized that scapular kinematics would be different between the horizontal and the vertical plane. Secondly, differences in scapular kinematics in the vertical plane between the open and closed chain were hypothesized.

METHODS

In this cross-sectional study, 48 patients (55 shoulders) aged 69 ± 7.4 years participated. Scapular kinematics in terms of anterior/posterior tilt, external/internal rotation, and upward/downward rotation were registered during 3 rehabilitation exercises. Exercises varied based on the plane (horizontal or vertical) and the modality (closed or open chain). Data were analyzed using statistical parametric mapping (SPM).

RESULTS

Post hoc pairwise analysis within SPM (SPM(t)) revealed no significant differences among the exercises regarding posterior tilt. During vertical plane exercises (standing wall slide 120° [WS] and standing reach 120° [REACH]), the scapula was more upwardly rotated for most of the time (14.93%-74.63%, P < .001) than during the exercise in the horizontal plane (seated bench slide). No statistically significant differences were found between the vertical open chain (REACH) and the vertical closed chain exercise (WS). For the internal/external rotation, significant differences were found between the horizontal (seated bench slide) and the vertical plane (WS and REACH) (0%-100%, P < .001), and between the open (REACH) and closed chain (WS) vertical exercises (3.0%-91.5%, P < .001), with more external rotation when performing the movement in the vertical plane, and in the closed chain compared with the horizontal plane and the open chain, respectively.

CONCLUSION

Scapular kinematics during rehabilitation exercises after rTSA differ, depending on the plane and modality of the exercise. Insight into the impact of changing the plane (horizontal/vertical), and training in open vs. closed chain, may assist physical therapists in the choice of exercises.

In vivo assessment of shoulder stability in dynamic rehabilitation exercises: A scoping review

BACKGROUND

The shoulder complex, which has the highest prevalence of instability, is currently, the subject of considerable debate regarding the methodologies used to assess shoulder stability during dynamic exercises.

RESEARCH QUESTION

The primary aim is to summarize evidence on various methodologies used to evaluate shoulder stability during dynamic exercises.

METHODS

This scoping review included cross-sectional studies focusing on various evaluation techniques to assess shoulder forces, kinetics, and stability during dynamic movements. In analyzing each study, the selected data included population profile, sample size, exercise type, and evaluation methodology used.

RESULTS

Twenty-seven studies with a total of 1187 subjects were included. Among the studies, various dynamic exercises were evaluated, including throwing exercises, movements with dumbbells or elastic bands, push-ups, and functional tasks. Most evaluation techniques were combined, with eleven studies using surface electromyography; seven used dynamometers to obtain direct strength measurements; two used six-force axis sensors; one utilized force platforms; and one was focused on the loss of speed using linear velocity transducers. Furthermore, motion capture systems such as high-speed cameras were used in fourteen studies. In conclusion, surface electromyography and high-speed cameras are the primary techniques for measuring muscle activity and kinetic and kinematic data. However, they do not directly measure glenohumeral stability, meaning further research is needed to develop reliable methodologies for this purpose.

SIGNIFICANCE

This study holds significant relevance in the field of shoulder instability and has clear clinical implications, as it establishes the primary tools for estimating glenohumeral stability, which could enable patient stratification and the design of optimal intervention programs based on these measurements.

Scapula dyskinesis in medium-sized full-thickness rotator cuff tear after subacromial Lidocaine infiltration and rotator cuff reconstruction

Purpose

In rotator cuff tears, scapular dyskinesis is often observed. The aim of our study is to better understand the cause and the role of scapular dyskinesis in rotator cuff tears and evaluate changes in scapulothoracic kinematics after Lidocaine subacromial injection and surgery in patients with medium-sized (1-3 cm) rotator cuff tear.

Methods

The scapular motion during humerus sagittal flexion of nine healthy persons (healthy group, HG) and nine persons with a medium-sized rotator cuff tear (surgery group, SG) was investigated using the VICON motion capture system and upper limb evaluation in movement analysis software. In addition, quality of life and functional outcomes were assessed in the SG group using American Shoulder and Elbow Surgeons, Oxford and Constant-Murley scores and rotator muscle force and Visual Analogue Scale score were evaluated. The SG was further divided into three subgroups: measurements were performed preoperatively (before surgery native subgroup-BSN), then after subacromial Lidocaine injection (before surgery injection subgroup-BSI) and 6 months after rotator cuff reconstruction (after surgery subgroup-AS). Changes observed after injection (BSI) and surgery (AS) were compared to the BSN.

Results

In the BSI, a significant reduction (p < .025) in protraction was observed in the raising phase between 20° and 70° comparing it to the BSN, protraction decreased by 5.3° ± 7.9° (mean ± standard deviation [SD]). In the lowering phase between 80° and 30°, we registered a decrease of protraction by 6.0° ± 8.3° (mean ± SD). In the AS, we observed an approximation of protraction to the HG, but no significant change was detected.

Conclusion

Significant reduction in scapular protraction was demonstrated with Lidocaine subacromial injection during both the arm raising and lowering phases. Six months of rehabilitation treatment in the postoperative period is not enough to fully eliminate scapular dyskinesis.

Level of Evidence

Level II.

Trans-axillary sonography in the ABER (ABduction and External Rotation) position: a window to the subscapularis, teres major and latissimus dorsi

Shoulder ultrasound is a key tool used by musculoskeletal practitioners to diagnose and treat a variety of upper girdle diseases. While magnetic resonance imaging is the cornerstone of shoulder imaging, sonography is readily available, practical and superior in its ability for dynamic assessment of musculoskeletal pathologies. The subscapularis, teres major and latissimus dorsi muscles are commonly involved in a myriad of pathology including myofascial pain and spasticity. There is scarce literature on the assessment of these muscles for diagnostic and therapeutic purposes. Conventional approaches to shoulder ultrasound have not included a dedicated assessment of the subscapularis muscle due to its inherent anatomical location deep to the scapular blade which blocks sound wave penetration. We describe an approach to visualizing the subscapularis muscle as a short addition to the established shoulder sonography format, which also permits assessment of both the latissimus dorsi and teres major muscles, which are important muscles for shoulder spasticity. The patient is imaged in a semi-recumbent position with the arms elevated above and behind the head in the ABduction and External Rotation (ABER) position. The relative ease of positioning and sonographic access to the musculature coupled with the potential for assessment and intervention makes this approach extremely desirable to the musculoskeletal practitioner looking to diagnose or treat muscle belly pathologies of the subscapularis, teres major or latissimus dorsi.

Kinematic stabilization after the Latarjet procedure: beyond the triple blocking effect

BACKGROUND

The rationale for the Latarjet procedure was described as the "triple blocking" effect. Satisfactory surgical outcomes have been reported after surgery. However, it has been reported that the "triple blocking" effect increases joint stability, but it does not fully restore it. Moreover, the procedure is nonanatomic and concerns remain regarding the effects. The study of scapulohumeral rhythm, which is a clinical parameter used for the functional evaluation of shoulder kinematics, can offer new perspectives on the rationale for the procedure. This study aimed to compare the shoulder kinematics of patients after the Latarjet procedure to the shoulders of a healthy population using magnetic and inertial measurement units with a motion analysis system.

METHODS

A retrospective study with prospective data collection was conducted on 28 patients who underwent the open Latarjet procedure for recurrent shoulder instability. At a minimum 12-month follow-up, each patient was evaluated by assessing the range of motion, the Rowe score, and the Constant-Murley score. Patients were examined using the ShowMotion 3D kinematic tracking system (NCS Lab, Modena, Italy), which uses wireless wearable noninvasive magnetic and inertial measurement units sensors to assess the three-dimensional kinematics of the shoulder. For each plane of elevation (ie, flexion and abduction), the scapulohumeral rhythm was described by three scapulothoracic rotations (ie, protraction-retraction, mediolateral rotation and posterior-anterior tilting) as a function of humeral anteflexion or humeral abduction.

RESULTS

The mean time from first shoulder dislocation to surgery was 6.6 ± 3 years (range, 1-12 years). No intraoperative complications occurred, and computed tomography (CT) performed 3 months after surgery showed graft union in all patients. After a mean follow-up time of 32.4 ± 20 months (range, 12-96), the mean Constant-Murley score and Rowe scores were 94.5 ± 4.8 (range, 84-100) and 96.7 ± 3.5 (range, 90-100), respectively. All patients showed no signs of glenohumeral arthritis on X-ray examination. Scapular posterior tilt and scapular internal rotation were significantly greater in the patient group than in the healthy population for the flexion-extension and abduction-adduction movements along the whole shoulder range of motion (all P < .05); no differences were found in upward/downward scapular rotation.

CONCLUSION

A greater scapular posterior tilt and scapular internal rotation were observed after the Latarjet procedure. The modified position of the scapula was maintained during the entire range of motion, suggesting a shoulder-stabilizing kinematic effect in addition to the bony, sling and bumper effects.

Effects of Sling-Suspension-Based Active Shoulder Joint Exercise on Shoulder Joint Subluxation, Pain, Muscle Strength, and Upper Limb Function in Patients with Subacute Stroke

Background and Objectives: We investigated the effects of sling-suspension-based active shoulder joint exercise training on shoulder joint subluxation, pain, muscle strength, and upper extremity function in patients with subacute stroke. Materials and Methods: Twenty-eight patients with subacute stroke were randomly assigned to either the sling-suspension-based active shoulder joint exercise (SASE) group (n = 14) or the motorized upper extremity exercise (MUEE) group (n = 14). The SASE group actively performed shoulder joint flexion, extension, abduction, adduction, external and internal rotation, and horizontal abduction and adduction using a sling suspension system, whereas the MUEE group underwent an exercise program using a motorized upper extremity exercise machine. All participants underwent a 4-week intervention with 30 min of exercise once a day for 5 days a week. Additionally, both groups received general physical therapy and functional electrical stimulation for 30 min twice a day for 5 days a week. Shoulder joint subluxation was measured by radiographic examination before and after training, and pain was evaluated in the splenius, upper trapezius, and infraspinatus muscles using pressure parameters. In addition, a manual muscle tester was used to assess the muscle strength of the shoulder joint flexors, extensors, abductors, adductors, and external and internal rotators, and the Fugl-Mayer Assessment (FMA) and Manual Functional Test (MFT) were used to evaluate upper extremity function. Results: A significant group-time interaction was observed for pain, with F-values of F(1, 26) = 7.470, p < 0.011 for the splenius and F(1, 26) = 9.623, p < 0.005 for the upper trapezius. A significant time-group interaction was observed for the muscle strength of the shoulder, with F-values of F(1, 26) = 13.211, p < 0.001; F(1, 26) = 4.974, p = 0.035 and F(1, 26) = 9.674, p = 0.004 for flexors, abductors, and external rotators, respectively. A significant time-group interaction was observed in the FMA, with F-values of F(1, 26) = 13.243, p < 0.001. When comparing the interaction effects between time and group for MFT scores, a significant difference was observed, with F-values of F(1, 26) = 32.386, p < 0.001. Conclusions: This study confirmed that sling-suspension-based active shoulder joint exercises are effective in improving shoulder joint subluxation, pain, muscle strength, and upper extremity function in patients with subacute stroke.

Biomechanical comparison shows increased stability of an arthroscopic subscapular sling procedure compared to an open Latarjet reconstruction for anterior shoulder instability in specimens with major glenoid bone defect

Purpose

Recurrent anterior glenohumeral instability (RASI) is commonly treated with arthroscopic techniques, though their effectiveness in providing stability may diminish in cases of critical glenoid bone loss. This study aimed to compare the stability outcomes and range of motion (ROM) associated with an arthroscopic subscapular sling procedure (SSP), first introduced in 2015.

Methods

Sixteen fresh-frozen human cadaveric shoulder specimens were biomechanically evaluated in four conditions: native, injured, post-SSP and post-LP. Glenohumeral translations were measured under anterior, anteroinferior and inferior loading, while external rotation ROM was assessed in neutral and abducted positions. Testing was conducted using a robotic system for precise force and torque application. Specimens were prepared with a 20% glenoid bone defect and subjected to stability testing sequentially.

Results

The SSP significantly reduced glenohumeral translations compared to LP, particularly under anterior loading in neutral (p < 0.001), external rotation (p = 0.007) and abduction (p < 0.001) positions. Although the SSP demonstrated superior stability in these key positions, it did not consistently outperform the LP across all scenarios, as stability was similar between the two in the abducted and rotated position under anterior loading (p = 0.379). Under anteroinferior loading, the SSP showed comparatively better stability at neutral (p = 0.003) and abduction (p < 0.001), whereas the LP led to greater anteroinferior translations in these same positions (p = 0.002 and p = 0.014, respectively). The SSP outperformed the LP under inferior loading in neutral (p = 0.005) and abduction (p = 0.02) positions, though it did not fully restore stability to native shoulder levels. The SSP maintained ROM similar to native shoulders. LP allowed greater ROM, potentially compromising stability.

Conclusion

The SSP provided greater stability than the open Latarjet in most positions and did not limit ROM, suggesting it could be a viable, less invasive option for managing shoulder instability.

Level of Evidence

Not applicable.

Scapulothoracic tenodesis using hamstring tendon graft for treatment of problematic scapula winging: A new surgical technique

Introduction

Winging of the scapula occurs due to dysfunction of its stabilising muscles, most commonly serratus anterior and/or trapezius, for example in facioscapulohumeral muscular dystrophy. Resultant loss of scapular control and abnormal kinematics can decrease shoulder function due to glenohumeral joint instability, loss of range of motion and pain. Previously described treatment for cases resistant to physiotherapy includes scapulothoracic arthrodesis which involves risk of non-union and metalwork failure, as well as reduced respiratory function due to immobilisation of a segment of the adjacent chest wall.

Technique

We present a novel surgical approach to the management of problematic scapular winging by using hamstring graft to achieve a scapulothoracic tenodesis.

Discussion

We believe this technique provides an adequately stable scapula for improved shoulder movement and function, a sufficiently mobile chest wall for improved lung function and avoidance of complications specifically associated with arthrodesis.

Preparation For Flight: The Physical Profile of Pre-Professional and Professional Circus Artists in the United States

Background

Established norms for fitness and performance measures are lacking in circus arts. These would assist healthcare professionals and coaches to screen for readiness to participate in training or performance, determine post-injury return to performance, and develop targeted conditioning programs.

Purpose

The purpose of this research was to establish norms for trunk and extremity physical exam and performance measures in circus artists by professional status, assigned sex at birth (ASAB), and age.

Study Design

Descriptive laboratory study.

Methods

Circus artists (n=201; ages 13-69y; 172 females ASAB, 29 males ASAB) from 10 cities across the United States underwent a baseline physical examination including shoulder, hip and trunk measures of passive (PROM) and active (AROM) range of motion, measures of flexibility (shoulder and hip), strength (manual muscle tests, grip strength), cardiovascular fitness (3 minute-step test), balance (single limb and handstand), and performance, (pull-ups, and the closed kinetic chain upper extremity stability test [CKCUEST]). ANOVAs were used to determine between group differences by age and T-tests to discern differences by ASAB or professional status.

Results

Differences existed by professional status for shoulder external rotation PROM, hip PROM, hip flexibility, shoulder and abdominal strength, and cardiovascular fitness. Sex differences were seen in active scapular upward rotation, hip and shoulder PROM and flexibility, hip and grip strength, and for functional performance measures (pull-ups, CKCUEST). Differences by age were limited to active scapular upward rotation, shoulder PROM, flexibility and strength, cardiovascular fitness, and balance. Overall, professionals outperformed pre-professionals for lower abdominal strength, pull-ups, handstand balance, cardiovascular fitness, hamstring, and straddle flexibility. Generally, males ASAB demonstrated greater shoulder flexibility and upper body functional strength while females ASAB had greater hip and lumbar flexibility and hip strength. No measures showed consistent declines with increasing age, though some showed differences between adolescents and adults.

Conclusion

These normative values for physical characteristics and functional performance in pre-professional and professional circus artists may be used to guide screening for readiness to participate in advanced training or performance, return to performance after injury, and the development of targeted strength and conditioning programs.

Level of Evidence

3.

Effectiveness of specific scapular therapeutic exercises in patients with shoulder pain: a systematic review with meta-analysis

Background

Therapeutic exercise has been considered a useful tool to rehabilitate shoulder pain, namely through its influence on scapular dynamics. Accordingly, the effectiveness of scapular therapeutic exercise needs to be explored. The present study aims to evaluate the effectiveness of scapular therapeutic exercises in shoulder pain and to identify the most effective exercise type (focal or multijoint) and ways of delivering them (as dose and progression).

Methods

Search was conducted at EMBASE, Cochrane Library, MEDLINE via PubMed, Web of Science, PEDro (Physiotherapy Evidence Database), and trial registration databases. The meta-analysis considered randomized controlled/crossover trials that compared the effect of scapular exercises against other types of intervention in the shoulder pain, shoulder function, scapular motion, and/or muscular activity. The risk of bias was assessed through the PEDro scale.

Results

From the 8318 records identified, 8 (high to low risk of bias- scoring from 4 to 8 on the PEDro scale) were included. The overall data, before sensitivity analysis, indicated that the scapular therapeutic exercises are: a) more effective than comparators in improving shoulder function (standardized mean difference [SMD] = 0.52 [95% Cl: 0.05, 0.99], P = .03, I2 = 76%); and b) as effective as comparators in reducing shoulder pain (SMD = 0.32 [95% Cl: -0.09, 0.73], P = .13, I2 = 70%). Subgroup analysis revealed that scapular exercises are more effective in improving shoulder function when the program duration is equal to or higher than 6 weeks (SMD = 0.43 [95% Cl: 0.09, 0.76] P = .01, I2 = 21%) and/or when the maximum number of exercise repetitions per session is lower than 30 (SMD = 0.79 [95% Cl: 0.15, 1.42], P = .01, I2 = 77%). Only 1 study considered scapular motion as an outcome measure, revealing therapeutic exercise effectiveness to improve scapular range of motion.

Conclusions

Intervention programs involving scapular therapeutic exercises are effective in improving shoulder function, presenting benefits when performed for 6 or more weeks and/or when used up to a maximum of 30 repetitions per exercise, per session.

Scapular Motor Control and Upper Limb Movement Quality in Subjects with and without Chronic Shoulder Pain: A Cross-Sectional Study

Despite the existence of several studies about the scapula’s position and motion, in shoulder pain conditions, there are still conflicting findings regarding scapular adaptations and reduced research about the scapula’s role during functional tasks. The present study aimed to compare scapular-related kinematic and electromyographic outcomes during different shoulder movements (with and without load) and the drinking task, between symptomatic and asymptomatic subjects. Forty subjects (divided into two groups) participated in this cross-sectional observational study. Scapulothoracic motion, scapulohumeral rhythm, and movement quality (considering trunk compensation, time-to-peak acceleration, and smoothness), as well as the relative surface electromyographic activity and muscle ratio considering the trapezius, serratus anterior, and levator scapulae (LS), were assessed. The symptomatic group presented the following: (1) changes in scapular upward rotation (p = 0.008) and winging (p = 0.026 and p = 0.005) during backward transport and drink phases; (2) increased muscle activity level of the middle trapezius (MT) in all tasks (p < 0.0001 to p = 0.039), of LS during shoulder elevation with load (p = 0.007), and of LS and LT during most of the drinking task phases (p = 0.007 to p = 0.043 and p < 0.0001 to p = 0.014, respectively); (3) a decreased serratus anterior lower portion activity level (SAlow) during shoulder lowering with load (p = 0.030) and drink phase (p = 0.047); and (4) an increased muscular ratio between scapular abductors/adductors (p = 0.005 to p = 0.036) and elevators/depressors (p = 0.008 to p = 0.028). Compared to asymptomatic subjects, subjects with chronic shoulder pain presented scapular upward rotation and winging adaptations; increased activity levels of MT, LT, and LS; decreased activity levels of SAlow; and increased scapular muscle ratios.

Differences in Osseous Shoulder Morphology, Scapulothoracic Orientation, and Muscle Volume in Patients With Constitutional Static Posterior Shoulder Instability (Type C1) Compared With Healthy Controls

BACKGROUND

Constitutional static posterior humeral decentering (type C1 according to ABC Classification) has been recognized as a pre-osteoarthritic deformity that may lead to early-onset posterior decentering osteoarthritis at a young age. Therefore, it is important to identify possible associations of this pathologic shoulder condition to find more effective treatment options.

PURPOSE

To perform a comprehensive analysis of all parameters reported to be associated with a C1 shoulder-including the osseous shoulder morphology, scapulothoracic orientation, and the muscle volume of the shoulder girdle in a single patient cohort.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective, comparative study was conducted analyzing 17 C1 shoulders in 10 patients who underwent magnetic resonance imaging (MRI) with the complete depiction of the trunk from the base of the skull to the iliac crest, including both humeri. The mean age of the patients was 33.5 years, and all patients were men. To measure and compare the osseous shoulder morphology (glenoid version, glenoid offset, humeral torsion, anterior acromial coverage, posterior acromial coverage, posterior acromial height, and posterior acromial tilt) and scapulothoracic orientation (scapular protraction, scapular internal rotation, scapular upward rotation, scapular translation, scapular tilt, and thoracic kyphosis), these patients were matched 1 to 4 according their age, sex, and affected side with shoulder-healthy patients who had received positron emission tomography (PET)-computed tomography. To measure and compare the muscle volume of the shoulder girdle (subscapularis, infraspinatus/teres minor, supraspinatus, trapezius, deltoid, latissimus dorsi/teres major, pectoralis major, and pectoralis minor), patients were matched 1 to 2 with patients who had received PET-MRI. Patients with visible pathologies of the upper extremities were excluded.

RESULTS

The C1 group had a significantly higher glenoid retroversion, increased anterior glenoid offset, reduced humeral retrotorsion, increased anterior acromial coverage, reduced posterior acromial coverage, increased posterior acromial height, and increased posterior acromial tilt compared with controls (P < .05). Decreased humeral retrotorsion showed significant correlation with higher glenoid retroversion (r = -0.742; P < .001) and higher anterior glenoid offset (r = -0.757; P < .001). Significant differences were found regarding less scapular upward rotation, less scapular tilt, and less thoracic kyphosis in the C1 group (P < .05). The muscle volume of the trapezius and deltoid was significantly higher in the C1 group (P < .05).

CONCLUSION

Patients with C1 shoulders differ from healthy controls regarding osseous scapular and humeral morphology, scapulothoracic orientation, and shoulder girdle muscle distribution. These differences may be crucial in understanding the delicate balance of glenohumeral centering.

Effect of scapular stabilization exercises on subacromial pain (impingement) syndrome: a systematic review and meta-analysis of randomized controlled trials

Objective

To evaluate the effectiveness of scapular stabilization exercises (SSE) in the treatment of subacromial pain syndrome (SAPS).

Methods

Clinical randomized controlled trials (RCTs) on SSE in the treatment of SAPS were searched electronically in PubMed, Science Direct, Cochrane Central Register of Controlled Trials (CENTRAL), EBSCOhost, Physiotherapy Evidence Database (PEDro), Web of Science, and other databases from 2000 to 2022, supplemented by manual search. Final RCTs were selected based on inclusion and exclusion criteria, and the Physiotherapy Evidence Database scale was used to evaluate the methodological quality of the study. A meta-analysis was conducted on data using the RevMan5.4 software.

Results

Eight RCTs involving 387 participants were included. The meta-analysis showed that the experimental group (SSE) had greater improvements in the Visual Analog Scale score [Weighted Mean Difference (WMD) = -0.94, 95% CI (-1.23, -0.65), p < 0.001] and the Shoulder Pain and Disability Index score [WMD = -10.10, 95% CI (-18.87, -1.33), p = 0.02] than the control group (conventional physical therapy). However, range of motion (ROM) was not found to be greater in the experimental group than in the control group.

Conclusion

Existing evidence moderately supports the efficacy of SSE for reducing pain and improving function in SAPS, without significant improvement in ROM. Future research should focus on larger, high-quality, standardized protocols to better understand SSE's effects across diverse SAPS populations, treatment, and outcome measures.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=307437, CRD42022307437.

Scapular muscle dynamic stiffness of asymptomatic subjects and subjects with chronic shoulder pain, at rest and isometric contraction conditions

Muscle stiffness had a crucial role in joint stability, particularly, at the shoulder complex. Although changes in upper trapezius muscle stiffness have been described for shoulder pain, contradictory findings have been obtained. Also, existing data regarding scapular muscles are, majorly, about trapezius. Myotonometry is a method used to assess stiffness; however, the reliability values of scapular muscle stiffness through this method have not been assessed in shoulder pain conditions. The present study aims to compare scapular muscles' stiffness (trapezius, serratus anterior, and levator scapulae) between subjects with and without chronic shoulder pain and to evaluate the related test-retest reliability. Twenty-two symptomatic and twenty-two asymptomatic subjects participated in a cross-sectional study. The dynamic muscular stiffness of scapular muscles, at rest and during an isometric contraction, was measured bilaterally with myotonometry, in two moments. The differences in bilateral averaged values between symptomatic and asymptomatic subjects and the effect of the group (group presenting pain in the dominant or non-dominant side, and asymptomatic group) and of the limb (unilateral painful or asymptomatic limb, and bilateral asymptomatic limbs) were investigated. Test-retest intra-rater reliability was determined. An effect of the group was observed at rest, for middle trapezius stiffness, and during contraction, for middle and lower trapezius stiffness. For middle trapezius, increased values were observed in the group presenting pain in non-dominant side comparing to both groups or to group presenting pain in dominant side. The intraclass correlation coefficient, majorly, ranged between 0.775 and 0.989. Participants with pain in the non-dominant side presented an increased middle trapezius' stiffness. Globally, high reliability was observed for scapular muscles dynamic stiffness.

Neutral posture education during cough can reduce urine leakage in women with cough-related stress urinary incontinence

BACKGROUND

Current literature highlights the difficulty in identifying an optimal educational technique for maintaining continence during cough.

OBJECTIVE

To characterize the effects of an educational intervention focusing on neutral posture during cough in women with cough-induced urinary incontinence (UI).

METHODS

This interventional study design included women with cough-induced UI. We recorded PFMs surface electromyographic (sEMG) peak activity, and assessed symptoms and quality of life (QoL) 6 weeks after the intervention. The effect of the experimental situation was estimated using a linear mixed model, sEMG measurements during coughing were indexed to each situation and adjusted to the resting value at, and a moderation analysis was used.

RESULTS/FINDINGS

Eighteen participants were included. The measurement situations (control versus experimental) did not have a statistically significant impact on sEMG peak activity during coughing: mean effect [95% CI] 3.42 [-1.28; 7.66]. Six weeks post-intervention, participants reported statistically significant decrease in urinary symptoms (P=0.0246) and significant improvement in QoL (P=0.00776). This was also particularly marked on the dimension related to effort activities (P=0.00162).

CONCLUSION

This study suggests that a brief educational intervention focusing on neutral posture during cough, without voluntary pre-contraction of the PFMs, has no clinically significant influence on sEMG peak activity of the PFMs in women with cough-induced UI. However, this intervention can lead to a significant improvement in urinary symptoms and QoL at 6 weeks. These improvements seem to be independent of electromyographic PFMs peak activity recorded during cough. As such, our preliminary results pave the way for future research.

LEVEL OF EVIDENCE

NP4.

Assessment of pediatric shoulder range of motion and loading response to evaluate the biofidelity of the Large Omni-directional Child (LODC) anthropomorphic test device (ATD) shoulder design

The shoulder girdle complex, through engagement with the seat belt, influences motor vehicle occupant upper body movement during frontal impacts, affecting the movement of the head and spine. The recently developed Large Omni-directional Child (LODC) anthropomorphic test device (ATD) was designed with flexible shoulder girdle structures that capture the unique kinematics in pediatric occupants. However, the LODC shoulder has not been evaluated for biofidelity due to the lack of biomechanical data available on pediatric shoulder responses. This study evaluated quasi-static pediatric shoulder girdle complex responses through non-invasive displacement measurements. These data were obtained to evaluate, and, if necessary, improve the biofidelity of the LODC ATD. Shoulder range of motion and anthropometric measurements were obtained from 25 pediatric volunteers, ages 8-12 years old. Loads were applied bilaterally exclusively to the shoulder complexes in increments of 25 N up to 150 N per shoulder at 90 and 135 degrees of shoulder flexion. Still photos were used to determine shoulder displacement in the sagittal plane from images captured prior to and following the load applications. Data analysis consisted of motion tracking to evaluate the absolute and relative displacement of the right acromion and T1. The displacements for each volunteer were normalized based on the volunteer's shoulder width compared to the shoulder width of the LODC ATD. For the 90° load, the acromion moved relative to T1 an average of 28.1 mm forward and 3.1 mm downward at maximum displacement. For the 135° load, the acromion moved relative to T1 an average of 15.5 mm forward and 42.7 mm upward at maximum displacement. Similar displacements at higher loads indicated that the volunteers achieved their maximum range of motion. The results of this study will be compared to the LODC ATD, assessing the biofidelity of the shoulder complex.

Scapular kinematics and muscle activity during Yi Jin Bang exercises

Introduction: Scapular dyskinesis is commonly associated with subacromial pain syndrome (SAPS). Addressing scapular dyskinesis is widely accepted as an important component of shoulder rehabilitation. Our previous randomized controlled trial showed that Yi Jin Bang (YJB) exercises could effectively manage SAPS, but scapular motions and muscle activity during YJB exercises remain unknown. This study examined scapular kinematics synchronously with scapular muscle activation during YJB exercises. Methods: Thirty healthy participants with no shoulder complaints were enrolled in this study. Three-dimensional (3D) scapular kinematics and electromyography (EMG) activation of the upper trapezius, middle trapezius, lower trapezius, serratus anterior, anterior deltoid, middle deltoid, and posterior deltoid were synchronously measured during nine YJB movements. Results: During all YJB movements, the scapula was upwardly rotated and anteriorly tilted, with more upward rotation and a similar or less anterior tilt than the mean resting scapular angle. Column rotation, arm crossover, shoulder support circle, and armpit support high lift generated more internal rotation than the mean resting scapular angle, with the angles of internal rotation significantly greater than the other five movements (p < 0.001). Regarding EMG activity, all YJB movements elicited low activity (1.42%-19.19% maximal voluntary isometric contraction [MVIC]) from the upper trapezius and posterior deltoid and low to moderate activity (0.52%-29.50% MVIC) from the middle trapezius, lower trapezius, serratus anterior, anterior deltoid, and middle deltoid. Conclusion: YJB exercises could be useful in the middle to later phases of shoulder rehabilitation. For patients with insufficient external rotation, some YJB movements should be prescribed with caution.

Exercise for rotator cuff tendinopathy: Proposed mechanisms of recovery

Rotator cuff (RC) tendinopathy is a common recurrent cause of shoulder pain, and resistance exercise is the first-line recommended intervention. Proposed causal mechanisms of resistance exercise for patients with RC tendinopathy consist of four domains: tendon structure, neuromuscular factors, pain and sensorimotor processing, and psychosocial factors. Tendon structure plays a role in RC tendinopathy, with decreased stiffness, increased thickness, and collagen disorganization. Neuromuscular performance deficits of altered kinematics, muscle activation, and force are present in RC tendinopathy, but advanced methods of assessing muscle performance are needed to fully assess these factors. Psychological factors of depression, anxiety, pain catastrophizing, treatment expectations, and self-efficacy are present and predict patient-reported outcomes. Central nervous system dysfunctions also exist, specifically altered pain and sensorimotor processing. Resisted exercise may normalize these factors, but limited evidence exists to explain the relationship of the four proposed domains to trajectory of recovery and defining persistent deficits limiting outcomes. Clinicians and researchers can use this model to understand how exercise mediates change in patient outcomes, develop subgroups to deliver patient-specific approach for treatment and define metrics to track recovery over time. Supporting evidence is limited, indicating the need for future studies characterizing mechanisms of recovery with exercise for RC tendinopathy.

The influence of shoulder position during multi-joint exercises in the relative scapular muscles activity in symptomatic and asymptomatic conditions

BACKGROUND

Scapular muscles changes, as increased upper trapezius activity and decreased middle and lower trapezius and serratus anterior muscle activity, have been demonstrated in shoulder pain specific or non-specific conditions. Shoulder external rotation exercises have been recommended to improve scapular activity in shoulder pain.

OBJECTIVE

To evaluate the relative scapular muscles activity during multi-joint exercises combining shoulder external rotation, trunk rotation and scapular squeeze.

METHODS

Forty-one participants with and without shoulder pain were assessed in a cross-sectional study. They performed isometric multi-joint exercises at 0∘ and 90∘ of shoulder abduction with and without support. The relative activity of upper, middle, and lower trapezius and serratus anterior (upper/middle and lower portions) was measured through electromyography. The scapular muscular balance was assessed by the ratio between relative activity of the upper trapezius and the other muscles.

Biomechanical and functional analysis of the shoulder complex and thoracic spine in patients with subacromial impingement syndrome: A case control study

The motions of the shoulder are mainly carried out through the glenohumeral joint, but are also assisted by the scapulothoracic joint. Therefore, changes in the biomechanics of the thoracic spine and scapula affect the function of the shoulder. However, there is limited information on the biomechanical and functional characteristics of the shoulder complex and thoracic spine in patients with subacromial impingement syndrome (SIS). In this study, the biomechanical and functional characteristics of the shoulder complex and thoracic spine were analyzed in patients with SIS compared to healthy individuals. A total of 108 participants were included in this study. Participants were classified into 2 groups, the SIS (n = 55) and healthy (n = 53) groups. The shoulder and thoracic range of motion (ROM), scapular position, and isokinetic shoulder strength were measured in all participants. The shoulder ROM was significantly decreased in the SIS group compared to the healthy group (P < .001). The thoracic spine ROM showed significantly limited extension in the SIS group (P < .001). The scapular position showed significantly increased anterior tilting (P = .005), internal rotation (P = .032), protraction (P < .001), and decreased upward rotation (P = .002) in the SIS group. The isokinetic shoulder external rotation (P < .001) and abduction (P < .001) strength were significantly lower in the SIS group. Patients with SIS showed reduced shoulder ROM and end-range extension of the thoracic spine compared to healthy individuals, and the scapula was in a more anterior-tilted, protracted, and downward rotated position. In addition, it showed lower external rotation and abduction strength. These results suggest the need for interventions to improve the limited thoracic extension and altered scapular position, which may affect shoulder ROM and muscle strength in the rehabilitation of patients with SIS.

Management of scapular dysfunction in facioscapulohumeral muscular dystrophy: the biomechanics of winging, arthrodesis indications, techniques and outcomes

Facioscapulohumeral muscular dystrophy (FSHD) is a common hereditary disorder which typically results in scapular winging due to wasting of the periscapular muscles affected by this condition. Scapulothoracic arthrodesis (STA) is the current surgical treatment for FSHD patients with severe winging and preserved deltoid muscle. There are several different techniques in the literature such as multifilament cables alone and cable or cerclage wires combined with single or multiple plates. We prefer cables without plates as it provides independent strong fixation points and strongly recommend utilization of autograft. The functional results of studies report that regardless of the technique used, shoulder elevation and thus quality of life is improved, as shown with outcome scores. There are several complications associated with STA. Pulmonary complications are common and usually resolve spontaneously. Meticulous surgical technique and effective postoperative analgesia may reduce the incidence. Scapular complications which are associated with the fixation may be encountered in the early or late period, which are related to the learning curve of the surgeon. In conclusion, STA is a reliable solution to a major problem in FSHD patients that helps them maintain their activities of daily living until a cure for the disease is found. A successful result is strongly dependent on patient selection, and a multidisciplinary team of neurologists, geneticists and orthopaedic surgeons is required to achieve good results.

Validity and Reliability of Wearable Motion Sensors for Clinical Assessment of Shoulder Function in Brachial Plexus Birth Injury

The modified Mallet scale (MMS) is commonly used to grade shoulder function in brachial plexus birth injury (BPBI) but has limited sensitivity and cannot grade scapulothoracic and glenohumeral mobility. This study aims to evaluate if the addition of a wearable inertial movement unit (IMU) system could improve clinical assessment based on MMS. The system validity was analyzed with simultaneous measurements with the IMU system and an optical camera system in three asymptomatic individuals. Test-retest and interrater reliability were analyzed in nine asymptomatic individuals and six BPBI patients. IMUs were placed on the upper arm, forearm, scapula, and thorax. Peak angles, range of motion, and average joint angular speed in the shoulder, scapulothoracic, glenohumeral, and elbow joints were analyzed during mobility assessments and MMS tasks. In the validity tests, clusters of reflective markers were placed on the sensors. The validity was high with an error standard deviation below 3.6°. Intraclass correlation coefficients showed that 90.3% of the 69 outcome scores showed good-to-excellent test-retest reliability, and 41% of the scores gave significant differences between BPBI patients and controls with good-to-excellent test-retest reliability. The interrater reliability was moderate to excellent, implying that standardization is important if the patient is followed-up longitudinally.

Patients with recurrent anterior shoulder instability exhibit altered glenohumeral and scapulothoracic joint kinematics during upper limb movement: A prospective comparative study

BACKGROUND

Altered shoulder kinematics in patients with recurrent anterior shoulder instability remains poorly understood. This prospective study aimed to quantify in vivo glenohumeral and scapulothoracic joint kinematics and joint-contact positions in patients with shoulder instability and healthy controls.

METHODS

Twenty patients with recurrent anterior shoulder instability (mean 28 years) and five patients without shoulder pathology (mean 39 years) were scanned using open CT in six static upper limb positions including 90° of abduction, combined abduction and external rotation, 90° of flexion, lift-off position (i.e. reaching behind the back) and the neutral shoulder with external rotation. Image datasets were digitally reconstructed to quantify shoulder joint kinematics and glenohumeral translation.

FINDINGS

At 90° of abduction, instability patients demonstrated significantly less glenohumeral abduction and a reciprocal increase in upward scapulothoracic rotation compared to controls (mean difference: 13.3°, p = 0.038). With the shoulder in combined abduction and external rotation, instability patients showed a significant increase in glenohumeral rotation and a reciprocal decrease in scapulothoracic rotation compared to controls (mean difference: 5.0°, p = 0.042). There were no significant differences in humeral head translation in the sagittal plane (anterior-posterior axis) for all motions tested (p > 0.05).

INTERPRETATION

Scapulothoracic and glenohumeral kinematics are significantly different between patients with recurrent anterior shoulder instability and those with a healthy shoulder. Instability patients compensate for reduced glenohumeral function during abduction by increasing scapular rotation. With the shoulder in combined abduction and external rotation position, greater glenohumeral joint angles without significantly increased humeral head translation suggest altered neuromuscular control in the unstable shoulder.

Fatigue Increases Muscle Activations but Does Not Change Maximal Joint Angles during the Bar Dip

The purpose of this study was to profile and compare the bar dip's kinematics and muscle activation patterns in non-fatigued and fatigued conditions. Fifteen healthy males completed one set of bar dips to exhaustion. Upper limb and trunk kinematics, using 3D motion capture, and muscle activation intensities of nine muscles, using surface electromyography, were recorded. The average kinematics and muscle activations of repetitions 2-4 were considered the non-fatigued condition, and the average of the final three repetitions was considered the fatigued condition. Paired t-tests were used to compare kinematics and muscle activation between conditions. Fatigue caused a significant increase in repetition duration (p < 0.001) and shifted the bottom position to a significantly earlier percentage of the repetition (p < 0.001). There were no significant changes in the peak joint angles measured. However, there were significant changes in body position at the top of the movement. Fatigue also caused an increase in peak activation amplitude in two agonist muscles (pectoralis major [p < 0.001], triceps brachii [p < 0.001]), and three stabilizer muscles. For practitioners prescribing the bar dip, fatigue did not cause drastic alterations in movement technique and appears to target pectoralis major and triceps brachii effectively.

Association between changes in pain or function scores and changes in scapular rotations in patients with subacromial shoulder pain: a prospective cohort study

Background

Scapular dyskinesis is reported as one of the potential factors contributing to the presentation of pain in subacromial shoulder pain. In clinical practice, the evaluation and control of scapular dyskinesis is considered important for managing the subacromial shoulder pain. The aim is to determine the association between changes in pain or function and changes in scapular rotations in participants with subacromial shoulder pain.

Method

Pain, function and scapular rotations were measured in 25 participants with subacromial shoulder pain at baseline and after 8 weeks. Pain was measured with Numeric Pain Rating Scale (NPRS) and function was measured with Patient Specific Functional Scale (PSFS). Scapular rotations were measured with a scapular locator at 60°, 90° and 120° of scapular arm elevation. Spearman rank correlations (r_s) were used to assess the association between variables.

Findings

No association was observed between changes in pain or function scores with changes in scapular upward/downward rotations (r_s = 0.03 to 0.27 for pain and − 0.13 to 0.23 for function) and scapular anterior/posterior tilt (r_s = − 0.01 to 0.23 for pain and − 0.13 to 0.08 for function) of arm at 60°, 90° and 120° elevation. Data associated with scapular internal/external rotation was not reported due to low reliability.

Conclusion

These findings reject associations between changes in pain or function scores and scapular rotations. Future observational study is warranted using a multifactorial approach to understand potential factors that contribute to the presentation of subacromial shoulder pain.

Altered corticospinal excitability of scapular muscles in individuals with shoulder impingement syndrome

The purpose of this study is to assess and compare corticospinal excitability in the upper and lower trapezius and serratus anterior muscles in participants with and without shoulder impingement syndrome (SIS). Fourteen participants with SIS, and 14 without SIS were recruited through convenient sampling in this study. Transcranial magnetic stimulation assessment of the scapular muscles was performed while the participants were holding their arm at 90 degrees scaption. The motor-evoked potential (MEP), active motor threshold (AMT), latency of MEP, cortical silent period (CSP), activated area and center of gravity (COG) of cortical mapping were compared between groups using the Mann-Whitney U tests. The SIS group demonstrated following significances, higher AMTs of the lower trapezius (SIS: 0.60 ± 0.06; Comparison: 0.54 ± 0.07, p = 0.028) and the serratus anterior (SIS: 0.59 ± 0.04; Comparison: 0.54 ± 0.06, p = 0.022), longer CSP of the lower trapezius (SIS: 62.23 ± 22.87 ms; Comparison: 45.22 ± 14.64 ms, p = 0.019), and posteriorly shifted COG in the upper trapezius (SIS: 1.88 ± 1.06; Comparison: 2.76 ± 1.55, p = 0.048) and the serratus anterior (SIS: 2.13 ± 1.02; Comparison: 3.12 ± 1.88, p = 0.043), than the control group. In conclusion, participants with SIS demonstrated different organization of the corticospinal system, including decreased excitability, increased inhibition, and shift in motor representation of the scapular muscles.

Assessment of the head, cervical spine, thoracic spine and shoulder girdle postures in people with and without chronic headache

Background/Aims

Cervical dysfunction is one of the common symptoms of chronic headaches. This study was conducted to assess the posture of the head, cervical and thoracic spine and the shoulder girdle in people with and without cervicogenic and migraine headaches.

Methods

The postural angles of the head, cervical and thoracic spine and the shoulder girdle in frontal and sagittal planes, as well as thoracic spine curvature, were measured on 90 people who were split into three groups: 20 people with cervicogenic headache, 20 people with migraine and 50 people as the control group.

Results

There were significant differences among the three groups in the craniovertebral angle, coronal head tilt angle and scapular upward rotation angle (P<0.05). There was no relationship between postural angles.

Conclusions

The results of this study revealed that forward head posture was evident in people with cervicogenic and migraine headache. Decreased scapular upward rotation seen in the migraine headache group highlights the importance of shoulder girdle-related dysfunctions in people with chronic headaches.

Publication Trends and Hot Spots in Subacromial Impingement Syndrome Research: A Bibliometric Analysis of the Web of Science Core Collection

Background

In recent years, the research on subacromial impingement syndrome (SIS) has gradually increased. Although the research directions are diverse, the overall research status and trend are not clear.

Objective

The aim of our study was to use bibliometric analysis to identify the trends in SIS-related research and to analyze the most highly cited scientific publications on SIS.

Methods

All data were retrieved from the Web of Science Core Collection database, and the year of publications, countries, journals, institutions and total number of citations were extracted and analyzed. The results related to countries, institutions and keywords were then analyzed using VOSviewer software and bibliometrics online analysis platform. And, we also identified the 100 most cited articles on SIS.

Results

A total of 548 articles related to AIS were identified. The frequency of publication on SIS has increased substantially over time. Among all countries, Turkey has contributed the most publications on SIS (n=118). The institution with the most articles was Istanbul University (n=17). Journal of Shoulder and Elbow Surgery topped the list of journals and has published 19 SIS-related publications. The hotspot of research changed from the former arthroscopic surgery to physical therapy and rehabilitation.

Conclusion

The scientific research on SIS has rapidly expanded in recent years. This study represents the first bibliometric analysis of SIS, gives us a systematic and comprehensive summary into the development of SIS.

Shoulder impingement: various risk factors for supraspinatus tendon tear: A case group study

A total of 680 cases of monolateral shoulder pain and functional impairment were included, and Chi-Squared tests was incorporated to test for possible associations.No relation between impingement syndrome and potential risk factors was found, such as presence of down slopping (P = .083), presence of ossification acromiale (P  = .102), presence of calcific tendinitis (P  = .144), types of acromion (I [P = .600], II [P = .536], III [P = .633] and IV [P = .832]) and grade of acromioclavicular degenerative changes (mild [P = .077], moderate [P = .111], and severe [P = .700]). However, a significant relationship was uncovered between impingement syndrome and risk factors such as gender (X2 = 7.004, df = 1, P = .08) (where females were more prone), history of shoulder dislocation (X2 = 19.440, df = 1, P = .001), presence of supraspinatus tendon tear or tendinopathy (X2 = 69.344, df = 1, P = .001) and supraspinatus complete tear (X2 = 13.593, df = 1, P = .001). A significant relationship was found between the type of supraspinatus pathology and factors such as gender (female more prone) (X2 = 34.719, df = 3, P = .01), presence of down slopping (X2 = 57.765, df = 3, P = .01), history of shoulder dislocation (X2 = 148.880, df = 3, P = .001), type III of the acromion (X2 = 12.979, df = 3, P = .005), presence of acromioclavicular generative changes mild (X2 = 76.408, df = 3, P = .001) and moderate (X2 = 29.697, df = 3, P = .001), and acromiohumeral distance of ≤3 mm (X2 = 18.915, df = 3, P = .001), 3.1 to 6 mm (X2 = 13.212, df = 3, P = .004), and 9.1-12 mm (X2 = 15.066, df = 3, P = .002). Overall, the Magnetic Resonance Imaging results yielded high sensitivity for detecting full-thickness supraspinatus tears.Considering the findings, this study may help radiologists understand the salient risk factors and identify which factors are mainly responsible for supraspinatus tendon tears and the respective grade of tear (articular partial, bursal partial, complete, or tendinopathy).

Clinical Characteristics of 100 Patients with Hypermobility Spectrum Disorders and Shoulder Complaints With or Without Mechanical Symptoms: A Cross-Sectional Study

OBJECTIVE

The aims were to describe the clinical characteristics of patients with hypermobility spectrum disorders (HSD) and shoulder complaints with or without mechanical symptoms, and to compare characteristics between these groups.

DESIGN

Descriptive study.

SETTING

Primary care PARTICIPANTS: One-hundred patients with HSD and shoulder complaints for at least three months were included from primary care.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Medical history, self-reported (shoulder pain and function, discomfort due to other symptoms, fatigue, fear of movement, quality of life) and objective (strength, range of motion, proprioception) characteristics were collected by physiotherapists. Mechanical symptoms (Yes/No) were defined as self-reported shoulder instability, subluxation, and/or laxity.

RESULTS

Sixty-seven reported mechanical symptoms. Patients in both groups reported impairments related to shoulder pain, function, fatigue, fear of movement, and quality of life. Patients with mechanical symptoms were younger (mean (95% CI): 35.1 (32.3; 37.9) vs. 43.3 (38.4; 48.1) years), had longer symptom duration (median: 46 (36; 66) vs. 24 (9; 56) months), reported a previous shoulder dislocation (25% (16; 37) vs. 3% (0; 16)), experienced that their shoulder was loose (64% (52; 76) vs. 15% (5; 32)), and reported discomfort due to other symptoms (OR 1.48 (1.17; 1.87)). Furthermore, a larger proportion had received supplemental treatment (analgesic medication, steroid injection/surgery).

CONCLUSION(S)

Both groups with HSD and shoulder complaints presented with substantial shoulder-related impairments. Two-thirds reported mechanical symptoms, were younger, and more severely impaired than those without mechanical symptoms. These findings highlight the importance of managing mechanical shoulder symptoms to fully address the patients' impairments.

Ratio between 3D glenohumeral and scapulothoracic motions in individuals without shoulder pain

This study determined the ratio between glenohumeral and three-dimensional scapular motion during arm elevation and lowering in 91 individuals without shoulder pain. Scapular kinematics were assessed using an electromagnetic tracking device. Individuals performed 3 repetitions of elevation and lowering of the arm in the sagittal plane. Two-way ANOVAs (interval: 30-60°, 60-90°, 90-120° x phase: elevation and lowering) and paired t-tests were used for data analysis. For scapular internal/external rotation, lesser scapular internal rotation contribution was found during the 60-90° interval as compared to the 90-60° interval. Lesser scapular external rotation was identified in the 60-30° interval of arm lowering. The ratio was greater during arm elevation (1.89) compared to lowering (1.74) across the entire motion arc. For scapular upward rotation, greater upward rotation contribution was observed during arm elevation at the 30-60° interval, and less scapular downward rotation contribution in the final range of arm lowering. For scapular tilt, lesser scapular posterior tilt contribution during arm elevation was observed compared to arm lowering. The ratios between glenohumeral elevation/lowering and each individual scapulothoracic motion showed either differences between intervals and/or between elevation and lowering during specific intervals in healthy individuals.

Diagnosis and epidemiology of winged scapula in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Winged scapula (WS) is a critical complication of axillary surgery in patients treated for breast cancer, and is associated with pain, impairment of the upper extremity's function and poor performance in daily activities.

SOURCES OF DATA

A systematic review and meta-analysis were performed following the PRISMA guidelines. Two independent reviewers searched PubMed, Embase and Virtual Health Library databases from January 1, 2000 to December 1, 2020. Clinical studies evaluating the diagnosis and epidemiology of WS among breast cancer surgery (BCS) patients were included.

AREAS OF AGREEMENT

The diagnosis of WS relies almost entirely on physical assessment. Studies have suggested a high variability in the report of the incidence of WS given the subjectivity of its diagnosis, and the different criteria used during clinical assessment.

AREAS OF CONTROVERSY

The diagnosis of WS in BCS patients remains a challenge given the lack of standardized diagnostic protocols. Physical examination cannot rely on one manoeuvre only, as it may overlook patients with subtle injuries or overweight and contributing to the underreporting of its incidence.

GROWING POINTS

BCS patients undergoing axillary lymph node dissection experience a significantly higher incidence of WS than those undergoing sentinel lymph node dissection. The global incidence of WS after BCS is 16.79%. Additionally, the anterior flexion test and the push-up test are the most commonly performed diagnostic manoeuvers.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies should aim for objective diagnostic tests, especially when the condition is not evident.

Shoulder-Abduction Angle and Trapezius Muscle Activity During Scapular-Retraction Exercise

CONTEXT

Scapular-retraction exercises are often prescribed to enhance scapular stabilization.

OBJECTIVE

To investigate upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT) activities and UT/MT and UT/LT ratios during scapular-retraction exercises with elastic resistance at different shoulder-abduction angles.

DESIGN

Descriptive laboratory study.

SETTING

Biomechanical analysis laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-five asymptomatic individuals.

MAIN OUTCOME MEASURE(S)

Surface electromyography was used to evaluate UT, MT, and LT activities during the scapular-retraction exercise at 0°, 45°, 90°, and 120° of shoulder abduction.

RESULTS

The mean muscle activity ranged from 15.8% to 54.7% maximal voluntary isometric contraction (MVIC) for UT, 30.5% to 51.6% MVIC for MT, and 21.4% to 25.5% MVIC for LT. A significant muscle × angle interaction was found (P < .001). Post hoc analysis revealed that the MT was more activated than the UT and LT during both retraction at 0° (P < .001 and P = .01, respectively) and 120° (P = .03 and P = .002, respectively). During retraction at 45° and 90°, the LT generated less activity than the UT (P = .02 and P = .03, respectively) and MT (P < .001 and P = .002, respectively). Further, UT/MT and UT/LT ratios during retraction at 0° were lower than at 45° (P = .03 and P = .001, respectively) and 90° (P < .001 and P < .001, respectively). Retraction at 90° resulted in a higher UT/LT ratio than at 45° (P = .004) and 120° (P = .004).

CONCLUSIONS

Due to less UT relative to MT activity, retraction at 0°, 45°, and 120° can be preferable in early shoulder training or rehabilitation. Additionally, retraction at 90° was the most effective exercise in activating all parts of the trapezius muscle.

Team Approach: Treatment of Shoulder Instability in Athletes

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Shoulder instability is a complex problem with a high rate of recurrence in athletes. Treatment of a first-time subluxation or dislocation event is controversial and depends on patient-specific factors as well as the identified pathology.

»

Athletic trainers and physical therapists are an integral part of the treatment team of an in-season athlete who has experienced a shoulder instability event. Through comprehensive physiological assessments, these providers can effectively suggest modifications to the patient's training regimen as well as an appropriate rehabilitation program.

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Surgical intervention for shoulder stabilization should use an individualized approach for technique and timing.

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A team-based approach is necessary to optimize the care of this high-demand, high-risk population.

Which Risk Factors Are Associated with Pain and Patient-reported Function in Patients with a Rotator Cuff Tear?

BACKGROUND

Patient-reported measures guide physicians in clinical decision making and therefore it is critical to determine what clinical factors are associated with these scores. Psychological and physical factors are commonly studied separately in patients with rotator cuff tears to determine their influence on outcomes. It is well established that psychological distress and scapular motion change in the presence of a symptomatic rotator cuff tear. However, these factors have not been studied simultaneously in a clinical setting to determine their association with shoulder outcome scores.

QUESTION/PURPOSE

After controlling for relevant confounding variables, what physical and psychological factors are associated with better (1) American Shoulder and Elbow Surgeons (ASES) scores for function, (2) ASES pain scores, and (3) total ASES scores?

METHODS

Fifty-nine patients with a potential symptomatic rotator cuff tear were recruited and agreed to participate in this cross-sectional study. Of those, 85% (50 of 59) met eligibility criteria for a primary diagnosis of an MRI-confirmed symptomatic partial-thickness or full-thickness rotator cuff tear without a history of shoulder surgery. Demographics, rotator cuff tear size, arm flexion, and clinical scapular motion during active arm flexion were evaluated by experienced examiners using standardized procedures. Patients completed the ASES questionnaire and the Optimal Screening for Prediction of Referral and Outcomes-Yellow Flag assessment form, which measures 11 different pain-related psychological distress symptoms. Three separate stepwise multiple linear regression analyses were performed for ASES pain, function, and total scores, with significance set at p < 0.05.

RESULTS

This model found that ASES function scores were associated with four factors: older age, increased arm flexion, increased percentage of scapular external rotation during arm flexion, and increased scores for acceptance of chronic pain (adjusted r2 = 0.67; p = 0.01). Those four factors appear to explain 67% of the observed variance in ASES function scores in patients with rotator cuff tears. Furthermore, increased percentage of scapular external rotation during arm flexion and decreased fear-avoidance beliefs related to physical activity scores (adjusted r2 = 0.36; p < 0.01) were associated with better ASES pain scores. And finally, better ASES total scores were associated with four factors: increased arm flexion, increased percentage of scapular upward rotation, increased scapular external rotation during arm flexion, and decreased fear-avoidance beliefs related to physical activity scores (adjusted r2 = 0.65; p < 0.001).

CONCLUSION

Our results favor adopting a comprehensive biopsychological clinical assessment for patients with rotator cuff tears that specifically includes humeral and scapular motion, fear-avoidance behaviors, and pain coping behaviors along with demographics. These particular physical and psychological variables were found to be associated with the ASES and, therefore, should be clinically examined simultaneously and targeted as part of a tailored treatment plan.

LEVEL OF EVIDENCE

Level II, prognostic study.

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review

STUDY DESIGN

This is a systematic review.

INTRODUCTION

Scapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear.

PURPOSE OF THE STUDY

The purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics.

METHOD

MEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment.

RESULTS

Eleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles.

DISCUSSION

Scapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial.

CONCLUSION

The results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.

Physiotherapy Rehabilitation in Subjects Diagnosed with Subacromial Impingement Syndrome Does Not Normalize Periscapular and Rotator Cuff Muscle Onset Time of Activation

Clinicians suggest that rehabilitation of Subacromial Impingement Syndrome (SIS) should target improving movement patterns to ensure better clinical outcomes. Understanding changes in onset time of activation patterns and associated changes in clinical outcomes could improve our understanding of rehabilitation strategies. In this prospective longitudinal study, we examined neuromuscular firing patterns and clinical features before and after a standardized physiotherapy program in subjects diagnosed with SIS. Electromyography (EMG) recordings of eleven shoulder muscles were taken at the initial and discharge consultation in 34 male volunteers diagnosed with SIS. EMG recording was performed during flexion, scaption, and abduction at slow, medium, and fast speeds with a loaded (3 kg) and unloaded arm, as well as rotational motion, rotational strength, pain, and shoulder function. Completion of standardized shoulder physiotherapy program for SIS resulted in improvements in clinical outcomes. Resulted showed inconsistent differences of onset time of activation mainly in some of the periscapular muscles for all movements. No differences were seen on the EMG recordings for rotator cuff muscles. Differences in range of motion, strength and function were shown. Despite some changes in onset time of activation, this study was not able to demonstrate consistent changes of onset time of activation of the periscapular and rotator cuff muscles.

The Relationship between Scapular Upward Rotation and Shoulder Internal and External Rotation Isokinetic Strength in Professional Baseball Pitchers

This study aims to assess the relationship between scapular upward rotation (SUR) across varying humeral-elevation angles (HEAs) and shoulder isokinetic strength and ratio in professional baseball pitchers. The subjects were professional baseball pitchers (n = 16) without a history of shoulder injury in the last six months. The subject’s SUR angles were measured with the humerus elevated at HEAs of 0° (at rest), 60°, 90°, and 120° to the scapular plane. Shoulder isokinetic strength was evaluated for shoulder internal rotation (IR) and external rotation (ER) strength (PT%BW and TW%BW), and the ER/IR strength ratios were determined at 60, 120 and 180°/s using an isokinetic dynamometer. The SUR angle at an HEA of 0° was positively correlated with IR strength at 120°/s (r = 0.535) and 180°/s (r = 0.522). The SUR angle at an HEA of 60° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.505) and 120°/s (r = −0.500). The SUR angle at an HEA of 90° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.574; r = −0.554) and 120°/s (r = −0.521; r = −0.589) as well as with ER strength at 180°/s (r = −0.591, r = −0.556). The SUR angle at an HEA of 120° was negatively correlated with ER strength at 60°/s (r = −0.558), 120°/s (r = −0.504; r = −0.524), and 180°/s (r = −0.543) and the ER/IR strength ratio at 60°/s (r = −0.517). In this study, we found that the ratio of isokinetic strength between ER and IR became closer to the normal range on increasing the SUR angle. In particular, an HEA of 90°, which resembles the pitching motion, showed a clear relationship between SUR, shoulder ER, and the ratio of ER/IR isokinetic strength in professional baseball pitchers.

Rehabilitation Following Posterior Shoulder Stabilization

Posterior shoulder instability has been noted in recent reports to occur at a higher prevalence than originally believed, with many cases occurring in active populations. In most cases, primary surgical treatment for posterior shoulder instability-a posterior labral repair-is indicated for those patients who have failed conservative management and demonstrate persistent functional limitations. In order to optimize surgical success and return to a prior level of function, a comprehensive and focused rehabilitation program is crucial. Currently, there is a limited amount of literature focusing on rehabilitation after surgery for posterior instability. Therefore, the purpose of this clinical commentary is to present a post-surgical rehabilitation program for patients following posterior shoulder labral repair, with recommendations based upon best medical evidence.

LEVEL OF EVIDENCE

5.

Scapulothoracic Dyskinesis: A Concept Review

PURPOSE OF REVIEW

Scapulothoracic dyskinesis (SD) occurs when there is a noticeable disruption in typical position and motion of the scapula, which can result in debilitating pain. The purpose of this review is to describe the current knowledge regarding the diagnosis and management of scapulothoracic dyskinesis by providing an evidence-based overview of clinical exams and treatment modalities available for orthopedic surgeons and provide insight into which treatment modalities require further investigation.

RECENT FINDINGS

SD is highly prevalent in athletes, particularly those participating in overhead activities (e.g., baseball, tennis, and swimming) and can coexist with several shoulder pathologies. A holistic approach in the diagnosis of SD has been supported in the literature; however, it is important to recognize that diagnosis is currently limited to the absence of a quantitative SD clinical assessment. The main goal of the treatment of SD is to regain proper scapular positioning and dynamics. The standard of care for the management of SD is conservative interventions aimed at optimizing scapular kinematics. Surgical intervention is only considered in the presence of concomitant pathology requiring surgery. Due to the complexity of coordinated movement of the shoulder girdle, recent literature has begun to move away from the use of traditional orthopedic tests, in favor of a more system-based approach for the diagnosis of SD. We present a concise review of clinical exams and treatment modalities available for orthopedic surgeons in the management of SD.

Acute effect of inhibitory kinesio-tape of the upper trapezius on lower trapezius muscle excitation in healthy shoulders

INTRODUCTION

Shoulder pain increases excitation of the upper trapezius (UT) and reduces excitation in the lower trapezius (LT). Despite inconclusive evidence, kinesio-tape (KT) is often used to modify muscular excitation within the UT and/or LT to help correct alterations in scapular position and motion associated with shoulder pain/injury. The objective of the current study was to determine if inhibitory KT to the UT acutely increases LT excitation and if load alters the magnitude of change in the excitation observed.

METHODS

Twenty-two (N = 22, 11 female) individuals with healthy shoulders (24 ± 3 years) completed 10 repetitions of an arm elevation task during 3 taping conditions (no-tape, experimental KT, sham KT) and 2 loading conditions (no load and loaded). Whole-muscle (mean grid) and spatial distribution (grid row) of LT excitation (root mean squared; RMS) was measured using a single high-density surface electromyography 32-electrode grid.

RESULTS

There was a main effect for loading condition on whole-muscle LT RMS, F (1, 19) = 38.038, p < .001, partial η² = 0.667. Whole-muscle LT RMS was significantly higher in the loaded condition (0.055 V ±0 .005) compared to the no-load condition (0.038 V ±0 .004). No effect of tape condition was observed on whole-muscle or spatial distribution of RMS.

CONCLUSION

Our findings suggest that inhibitory KT to the UT does not alter whole-muscle excitation or shift the distribution of excitation within the LT during a repeated arm elevation task in healthy shoulders.

Scapular kinematics during unloaded and maximal loaded isokinetic concentric and eccentric shoulder flexion and extension movements

Characterization of scapular kinematics under demanding load conditions might aid to distinguish between physiological and clinically relevant alterations. Previous investigations focused only on submaximal external load situations. How scapular movement changes with maximal load remains unclear. Therefore, the present study aimed to evaluate 3D scapular kinematics during unloaded and maximal loaded shoulder flexion and extension. Twelve asymptomatic individuals performed shoulder flexion and extension movements under unloaded and maximal concentric and eccentric loaded isokinetic conditions. 3D scapular kinematics assessed with a motion capture system was analyzed for 20° intervals of humeral positions from 20° to 120° flexion. Repeated measures ANOVAs were used to evaluate kinematic differences between load conditions for scapular position angles, scapulohumeral rhythm and scapular motion extent. Increased scapular upward rotation was seen during shoulder flexion and extension as well as decreased posterior tilt and external rotation during eccentric and concentric arm descents of maximal loaded compared to unloaded conditions. Load effects were further seen for the scapulohumeral rhythm with greater scapular involvement at lower humeral positions and increased scapular motion extent under maximal loaded shoulder movements. With maximal load applied to the arm physiological scapular movement pattern are induced that may imply both impingement sparing and causing mechanisms.

Evaluation of scapular mobilization and comparison to pectoralis minor stretching in individuals with rounded shoulder posture: A randomized controlled trial

BACKGROUND

Rounded shoulder posture (RSP) is a common postural condition which can alter scapular position. Although, there is no consensus on the relationship between posture and musculoskeletal dysfunction, some evidence suggests a significant relationship between RSP and shoulder dysfunction. Therefore, treatment of this postural condition is important. Various treatment methods are used to correct RSP. However, the effectiveness of scapular mobilization, (SM) as a method which can alter scapular kinematics, has not been investigated.

OBJECTIVE

To evaluate the effects of SM on scapular resting position in individuals with RSP, and to compare this technique to pectoralis minor self-stretching (PMS), and combined SM + PMS.

METHODS

52 healthy students (18 men and 34 women; mean age 23.67 ± 6.73 years) with RSP were randomly assigned to four groups (SM, PMS, combined SM + PMS, control). The mobilization group received SM, the stretching group performed self-PMS, and the combined group received SM + PMS. The control group received no treatment. Kinematics data to measure scapular protraction (cm), anterior tilt (°), internal rotation (°), and downward rotation (°) were captured with a motion analysis system before and after 5 sessions of group intervention.

RESULTS

All variables decreased significantly post-intervention compared to baseline values (P < 0.05). Internal rotation and downward rotation decreased significantly in the intervention groups compared to the control group (P < 0.05). No significant differences were observed between the intervention groups.

CONCLUSION

SM appears to be an effective technique to change scapular resting position in individuals with RSP. However, this technique was not superior to PMS or a combination of SM + PMS.

Scapular movement impairments in individuals with subacromial pain syndrome based on scapular assistance test and scapula reposition test outcomes

BACKGROUND

Individuals with subacromial pain present with a variety of contributing impairments related to the movement problem. The scapular assistance test (SAT) and scapula reposition test (SRT) are proposed to identify shoulder pain related to abnormal scapular movement or position. It remains unknown if scapular movement related impairments are present in those with positive tests.

OBJECTIVES

To determine if scapular motion related impairments differ based on the result of the SAT or SRT in individuals with subacromial pain syndrome.

DESIGN

Cross-sectional METHOD: Sixty individuals with subacromial pain syndrome were included. Prior to obtaining results of the SAT and SRT, a single examiner measured scapular upward rotation and posterior tilt active and passive motion, pectoralis minor length, and strength of the middle trapezius, lower trapezius, and serratus anterior. Dynamic scapular motion was qualitatively assessed with the Scapular Dyskinesis Test. The Mann-Whitney U test assessed for differences based on the outcome of the SAT and SRT.

RESULTS

There was a significant difference (P = .023) in pectoralis minor length for the SAT. Participants with a positive SAT had decreased muscle length compared to those who tested negative. There were no significant differences in scapular motion or strength based on the result of either the SAT or SRT.

CONCLUSIONS

A positive SAT was associated with greater pectoralis minor length impairment, but not muscle strength or mobility. The SRT did not identify greater impairments in any of the scapular movement related impairments assessed. Individuals may vary in contributing impairments related to SAT or SRT results.

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.

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.

Subacromial Impingment Syndrome does not alter muscle onset activation patterns during shoulder cardinal movement at different speed and load

This study examines neuromuscular firing patterns in healthy and subjects diagnosed with SIS of the periscapular, prime-moving, and rotator cuff muscles during "clinical" cardinal plane physiological movements at different speeds and loads. EMG recordings were taken in 34 healthy and 34 subjects diagnosed with Subacromial Impingement Syndrome (SIS) of the prime movers, periscapular, and rotator cuff muscles during flexion, scaption, and abduction performed at fast, medium, and slow speeds with a loaded (3 kg) and unloaded arm. Differences in firing patterns between groups were analyzed by fitting mixed linear models with random intercepts per subject, and fixed factors for group, muscle, movement type, speed, and load. No difference in timing of activation was seen between the healthy and SIS. Onset timing of prime movers, periscapular, and rotator cuff muscles were prior to movement in all scenarios studied, with rotator cuff muscles firing last. Speed and load appear to independently vary muscle activation timing in a non-intuitive manner in both healthy and SIS. The lack of different firing neuromuscular patterns in subjects diagnosed with SIS and healthy subjects raises the need to consider individual assessment of motor patterns rather than generalized patterns.

Effect of scapular stabilization exercise program in patients with subacromial impingement syndrome: a systematic review

Scapular stabilization approaches have been a mainstay of therapeutic training programs in the recent past for patients with subacromial im-pingement syndrome, whereas its contributions solely in the clinical outcome of reducing shoulder pain and disability are largely unclear. This systematic review aims to evaluate and summarize the best evi-dence regarding the role of scapular stabilization interventions in allevi-ating shoulder dysfunction among subjects with subacromial impinge-ment syndrome. Six reviewers involved in this systematic review. Liter-ature was retrieved systematically through searching 5 electronic data-bases (PubMed, MEDLINE, CINAHL, Cochrane, and Google Scholar). Articles published from the year 2010 up to and including 2019 were in-cluded. The literature search included clinical trials those intervened subjects with scapular exercises or scapular stabilization exercises or scapular rehabilitation, as an intervention for subacromial impingement syndrome. Seven studies, totaling 228 participants were included in this systematic review. Articles included in this review were graded ac-cording to Lloyd-Smith hierarchy of evidence scale and critically ap-praised with a tool developed by National, Heart, Lung and Blood Insti-tute (United States), named as quality assessment of controlled inter-vention studies tool. There was a significant effect on the scapular sta-bilization exercise program on improving pain and disability among sub-jects with subacromial impingement syndrome. This systematic review provides sufficient evidence to suggest that scapular stabilization exer-cises offers effectiveness in reducing pain and disability among sub-jects with subacromial impingement syndrome. However, more trials with larger sample are needed to provide a more definitive evidence on the clinical outcomes of scapular stabilization exercises among pa-tients with impingement.

Analysis of Scapular Kinematics and Muscle Activity by Use of Fine-Wire Electrodes During Shoulder Exercises

BACKGROUND

During nonoperative or postoperative rehabilitation after sports injuries, exercise selection is often based on minimal load on the injured/repaired glenohumeral structures, while optimally activating scapulothoracic muscles. Previous research explored scapular muscle activity during rehabilitation exercises using surface electromyography (EMG). However, limited information exists about the deeper lying muscle activity, measured with fine-wire electrodes, even more in combination with 3-dimensional scapular kinematics.

PURPOSE

To report scapular kinematics synchronously with surface and fine-wire EMG during specific shoulder exercises for early rehabilitation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 23 healthy male patients were recruited. Three-dimensional scapular kinematics were measured combined with EMG recording of 8 muscles during 4 commonly used shoulder exercises (inferior glide, low row, lawnmower, and robbery). Upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior muscle activities were measured with bipolar surface electrodes. Intramuscular electrodes were placed in the levator scapulae (LS), rhomboid major (RM), pectoralis minor (Pm), and infraspinatus (IS) muscles. All data were normalized as a percentage of maximal voluntary isometric contraction (%MVIC). A linear mixed model with Bonferroni correction was applied for statistical analysis.

RESULTS

Scapular kinematics revealed an anterior tilt position during the inferior glide, low row, and robbery (P < .05). An upward rotation position between 20° and 30° was reached in all exercises except low row. Inferior glide (31°) and low row (42°) represented a significantly increased internal rotation position compared with lawnmower and robbery. Lawnmower and robbery showed significantly (P < .05) more MT (lawnmower, 36% MVIC; robbery, 39% MVIC) and RM (lawnmower, 59% MVIC; robbery, 66% MVIC) activation compared with inferior glide and low row. Lawnmower and robbery showed significantly (P < .05) less Pm activation (9.5%-12% MVIC). LS was significantly more active during robbery (58% MVIC) compared with inferior glide and low row (27%-36% MVIC) (P < .05). IS showed moderate activity (24%-37% MVIC) for all exercises, except low row (13% MVIC).

CONCLUSION/CLINICAL RELEVANCE

This study provides new insights about scapular positions and activation of the deeper layer muscles during 4 commonly used shoulder rehabilitation exercises. The lawnmower showed a favorable position of the scapula with less Pm activity in contrast to the low row. The inferior glide, lawnmower, and robbery should not be implemented in early phases of shoulder rehabilitation because of their moderate muscle activity.