The scapular dyskinesis test: Reliability, agreement, and predictive value in patients with subacromial impingement syndrome

Is it Time to Normalize Scapular Dyskinesis? The Incidence of Scapular Dyskinesis in Those With and Without Symptoms: a Systematic Review of the Literature

Background

Up to 67% of adults experience shoulder pain in their lifetime. Numerous factors are related to the etiology of shoulder pain, one of which is thought to be scapular dyskinesis (SD). Given the prevalence of SD among the asymptomatic population a concern is that the condition is being medicalized (clinical findings suggested to require treatment but is ultimately a normal finding). Therefore, the purpose of this systematic review was to investigate the prevalence of SD among both symptomatic and asymptomatic populations.

Methods

A systematic review of the literature up to July of 2021. Relevant studies identified from PubMed, EMBASE, Cochrane and CINAHL were screened utilizing the following inclusion and exclusion criteria; inclusion: (a) individuals being assessed as having SD, including reliability and validity studies (b) subjects aged 18 or older; (c) sport and non-sport participants; (d) no date restriction; (e) symptomatic, asymptomatic, or both populations; (f) all study designs except case reports. Studies were excluded if: (a) they were not published in the English language; (b) they were a case report design; (c) the presence of SD was part of the studies inclusion criteria; (d) data were not present distinguishing the number of subjects with or without SD; (e) they did not define participants as having or not having SD. Methodological quality of the studies was assessed utilizing the Joanna Briggs Institute checklist.

Results

The search resulted in 11,619 after duplicates were removed with 34 studies ultimately retained for analysis after three were removed due to low quality. A total of 2,365 individuals were studied. Within the studies for the symptomatic athletic and general orthopedic population there were 81% and 57% individuals with SD, respectively, and a total of 60% among both symptomatic groups (sport and general orthopedic population). Within the studies for the asymptomatic athletic and general population there were 42% and 59% individuals with SD, respectively, and a total of 48% among both asymptomatic groups (sport and general orthopedic population).

Limitation

A strict inclusion and exclusion criteria was used to identify studies that provided the appropriate data for the purpose of this study. There was a lack of consistency for measuring SD across studies.

Conclusion

A considerable number of individuals with shoulder symptoms do not present with SD. More revealing is the number of asymptomatic individuals who do present with SD, suggesting that SD may be a normal finding among nearly half of the asymptomatic population.

Level of Evidence

2a.

Reliability of the scapular dyskinesis test yes-no classification in asymptomatic individuals between students and expert physical therapists

BACKGROUND

Scapular dyskinesis is considered a risk factor for the shoulder pain that may warrant screening for prevention. Clinicians of all experience screen scapular dyskinesis using the scapular dyskinesis test yes-no classification (Y-N), yet its reliability in asymptomatic individuals is unknown. We aimed to establish Y-N's intra- and inter-reliability between students and expert physical therapists.

METHODS

We utilized a cross-sectional design using consecutive asymptomatic subjects. Six students and two experts rated 100 subjects using the Y-N. Cohen's kappa (κ) and Krippendorff's alpha (K-α) were calculated to determine intra- and inter-rater reliability.

RESULTS

Intra- and inter-rater values for experts were κ=0.92 (95% confidence interval [CI], 0.91-0.93) and 0.85 (95% CI, 0.84-0.87) respectively; students were κ=0.77 (95% CI, 0.75-0.78) and K-α=0.63 (95% CI, 0.58-0.67).

CONCLUSIONS

The Y-N is reliable in detecting scapular dyskinesis in asymptomatic individuals regardless of experience.

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.

Diagnosis and Treatment of Snapping Scapula Syndrome: A Scoping Review

CONTEXT

Snapping scapula syndrome (SSS) is commonly misdiagnosed and underreported due to lack of awareness.

OBJECTIVE

This scoping review aims to summarize the current evidence related to SSS diagnosis and treatment to aid clinicians in managing the condition more effectively.

DATA SOURCES

PubMed, Medline, and Embase databases were searched for studies related to the etiology, diagnosis, or treatment of SSS (database inception to March 2020).

STUDY SELECTION

Databases were searched for available studies related to the etiology, diagnosis, or treatment of SSS.

STUDY DESIGN

A scoping review study design was selected to explore the breadth of knowledge in the literature regarding SSS diagnosis and treatment.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Primary outcomes abstraction included accuracy of diagnostic tests, functional outcomes, and pain relief associated with various nonoperative and operative treatment options for SSS.

RESULTS

A total of 1442 references were screened and 40 met the inclusion criteria. Studies commonly reported SSS as a clinical diagnosis and relied heavily on a focused history and physical examination. The most common signs reported were medial scapular border tenderness, crepitus, and audible snapping. Three-dimensional computed tomography had high interrater reliability of 0.972, with a 100% success rate in identifying symptomatic incongruity of the scapular articular surface. Initial nonoperative treatment was reported as successful in most symptomatic patients, with improved visual analogue scale (VAS) scores (7.7 ± 0.5 pretreatment, to 2.4 ± 0.6). Persistently symptomatic patients underwent surgical intervention most commonly involving bursectomy, superomedial angle resection, or partial scapulectomy. High satisfaction rates of surgery were reported in VAS (6.9 ± 0.7 to 1.9 ± 0.9), American Shoulder and Elbow Surgeons scores (50.3 ± 12.2 to 80.6 ± 14.9), and mean simple shoulder test scores (5.6 ± 1.0 to 10.2 ± 1.1).

CONCLUSION

Focused history and physical examination is the most crucial initial step in the diagnostic process, with supplemental imaging used to assess for structural etiologies when nonoperative management fails. Nonoperative management is as effective as surgical management in pain relief and is advised for 3 to 6 months before operative treatment.

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

PURPOSE

Aim of this study is to establish an objective and easily applicable method that will allow clinicians to quantitatively assess scapular dyskinesis during clinical examination using a computer tablet software. Hypothesis is that dyskinetic scapulae present greater motion-deviation from the thoracic wall-compared to the non-dyskinetic ones and that the software will be able to record those differences.

METHODS

Twenty-five patients and 19 healthy individuals were clinically evaluated for the presence of dyskinesis or not. According to the clinical diagnosis, the observations were divided into three groups; A. Dyskinetic scapulae with symptoms (n = 25), B. Contralateral non-dyskinetic scapulae without symptoms (n = 25), C. Healthy control scapulae (n = 38). Then, all individuals were tested using a tablet with the PIVOT™ image-based analysis software (PIVOT, Impellia, Pittsburgh, PA, USA). The motion produced by the scapula medial border and inferior angle deviation from the thoracic wall was recorded.

RESULTS

The deviation of the medial border and inferior angle of the scapula from the thoracic wall was 24.6 ± 7.3 mm in Group A, 14.7 ± 4.9 mm in Group B, and 12.4 ± 5.2 mm in Group C. The motion recorded in the dyskinetic scapulae group was significantly greater than both the contralateral non-dyskinetic scapulae group (p < 0.01) and the healthy control scapulae group (p < 0.01).

CONCLUSION

The PIVOT™ software was efficient to detect significant differences in the motion between dyskinetic and non-dyskinetic scapulae. This system can support the clinical diagnosis of dyskinesis with a numeric value, which not only contributes to scapula dyskinesis grading but also to the evaluation of the progress and efficacy of the applied treatment, thus providing a feedback to the clinician and the patient.

LEVEL OF EVIDENCE

IV, laboratory study.

Heterogeneity among patients with subacromial pain - variabilities within clinical presentation and its impact on daily life

OBJECTIVE

The primary aim was to describe the variability within clinical presentation of patients with subacromial pain in primary care, secondly to investigate associations between clinical presentation and self-reported pain intensity, shoulder function, level of anxiety and depression, and health-related quality of life.

DESIGN AND SETTING

A cross-sectional study based on data from two clinical studies in primary care, one randomized controlled trial and one implementation study. Three components: active range of motion (AROM), rotator cuff function and scapular kinematics were analyzed to describe variability within clinical presentation and patient-reported measurements were used to investigate the impact on daily life.

PARTICIPANTS

Patients aged 30-67 years, describing pain for more than two weeks, with positive signs for a minimum of three out of the following five clinical tests: impingement sign according to Neer, impingement test according to Hawkins-Kennedy, Pattes maneuver, Jobe's test, and painful arc.

RESULTS

Among the 164 patients included, 24% displayed dysfunction in one, 50% two and 24% in all three components. Limited AROM was seen in 46%, rotator cuff dysfunction in 91% and scapular dyskinesia in 57% of the patients.

CONCLUSIONS

These results reveal a heterogeneity among primary care patients with subacromial pain confirming a large variability regarding the components AROM, rotator cuff function and scapular kinematics. All three components appear unique (not significantly correlated) where a rotator cuff dysfunction is very frequent while limited AROM and scapular dyskinesia are more inconsistent. There are significant, but rather weak, associations between clinical presentation and impact on daily life.

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.

Is there an association between changes in pain or function with changes in scapular dyskinesis: A prospective cohort study

OBJECTIVE

To assess the association between changes in pain or function with changes in scapular dyskinesis in participants with subacromial shoulder pain.

METHOD

Forty-four participants with subacromial shoulder pain were assessed at baseline and 8 weeks later. The outcome measures included 'pain at rest' and 'pain during movement' using Numeric Pain Rating Scale (NPRS), shoulder function using Patient Specific Functional Scale (PSFS), and observation of scapular movement pattern using the scapular dyskinesis test. Robust paired t-tests were used to compare scores between baseline and follow-up. Repeated measures correlation coefficient was used to assess the association between changes in pain or function with changes in scapular dyskinesis scores.

RESULTS

A fair association was found between improvement in function and improvement in scapular dyskinesis (correlation coefficient = -0.4, 95% CI: -0.6 to -0.1). No associations were found between changes in 'pain at rest' (correlation coefficient = -0.1, 95% CI: -0.2 to 0.2) or 'pain during movement' (correlation coefficient = 0.28, 95% CI: 0.0 to 0.5) with changes in scapular dyskinesis.

CONCLUSION

Our findings showed improvement in function is associated with improvement in scapular dyskinesis scores. Future studies should explore whether there is causal effect between improvement in scapular dyskinesis and function.

The Effect of Repeated Shoulder Motion on Scapular Dyskinesis in Army ROTC Cadets

INTRODUCTION

Altered or abnormal scapular motion has been associated with increased shoulder pain and dysfunction. Fatigue of the scapular stabilizing muscles resulting from repeated arm motion has been reported to alter scapular kinematics, which could result in the clinical assessment of scapular dyskinesis. The purpose of this study was to characterize the effect of repeated arm motion on the development of scapular dyskinesis. The hypothesis was that repeated arm motion will induce a subtle or obvious scapular dyskinesis.

MATERIALS AND METHODS

About 30 army Reserve Officer Training Corps (ROTC) cadets participated in the research study. The cadets level of shoulder function was determined using the Quick Disabilities of the Arm Shoulder and Hand and Pennsylvania Shoulder Score shoulder scores. Cadets performed an exercise protocol of 30 repetitions of weighted shoulder motion in the frontal plane. Shoulder and scapular musculature strength measurements were recorded prior to and immediately following the exercise protocol using hand-held dynamometry. The scapular dyskinesis test was performed prior to the exercise protocol and during the last five repetitions of the exercise protocol.

RESULTS

Prior to the exercise, protocol 3/30 were categorized with scapular dyskinesis on the left side and 3/30 were categorized with scapular dyskinesis on their right side. Following the exercise, protocol 8/30 were categorized with left-side scapular dyskinesis (χ2 = 9.167, P = 0.002) and 6/30 with right-side dyskinesis (χ2 = 4.537, P = 0.033). Shoulder strength decreased following the exercise protocol for all participants. The participants that developed scapular dyskinesis were weaker than those with normal scapular motion. However, the difference did not reach statistical significance. Participants graded with obvious scapular dyskinesis following the exercise protocol reported higher Quick Disabilities of the Arm Shoulder and Hand scores (P = 0.04) and lower scores on the Pennsylvania Shoulder Score (P = 0.005).

CONCLUSIONS

Repeated shoulder motion increased the frequency of scapular dyskinesis in army ROTC cadets. The cadets that developed scapular dyskinesis also reported greater disability and lower function of the upper extremity. The results provide a link between scapular dyskinesis, upper extremity function, and the strength of the scapular stabilizing muscles. Improving the strength of the scapular stabilizing musculature might reduce the effects of repeated arm motions.

Scapular Dyskinesis: From Basic Science to Ultimate Treatment

Background: This study intends to summarize the causes, clinical examination, and treatments of scapular dyskinesis (SD) and to briefly investigate whether alteration can be managed by a precision rehabilitation protocol planned on the basis of features derived from clinical tests. Methods: We performed a comprehensive search of PubMed, Cochrane, CINAHL and EMBASE databases using various combinations of the keywords “Rotator cuff”, “Scapula”, “Scapular Dyskinesis”, “Shoulder”, “Biomechanics” and “Arthroscopy”. Results: SD incidence is growing in patients with shoulder pathologies, even if it is not a specific injury or directly related to a particular injury. SD can be caused by multiple factors or can be the trigger of shoulder-degenerative pathologies. In both cases, SD results in a protracted scapula with the arm at rest or in motion. Conclusions: A clinical evaluation of altered shoulder kinematics is still complicated. Limitations in observing scapular motion are mainly related to the anatomical position and function of the scapula itself and the absence of a tool for quantitative SD clinical assessment. High-quality clinical trials are needed to establish whether there is a possible correlation between SD patterns and the specific findings of shoulder pathologies with altered scapular kinematics.

Comprehensive movement system screening tool (MSST) for athletes: Development and measurement properties

OBJECTIVES

Non-traumatic extremity injuries are particularly common in sports, representing a significant economic, academic, and psychosocial burden on athletes. Proposed musculoskeletal risk factors for increased injury and decreased performance in athletes include movement pattern inefficiency, decreased regional stability, decreased mobility, and asymmetrical movement. The Movement System Screening Tool (MSST) is a comprehensive screening tool designed to assess these factors. Thus, the purpose of this study was to describe the development and determine the content and construct validity and inter-rater reliability of the MSST.

METHODS

A modified Delphi panel of experts determined content validity. 80 athletes (40 with and 40 without a current non-traumatic shoulder injury) completed 21 clinical tests, with exploratory factor analysis and known group analysis performed to determine construct validity. Two independent raters were used to establish individual item and composite score inter-rater reliability.

RESULTS

Exploratory factor analysis identified three of the four apriori constructs over 7 factors (14 tests), representing 63% of the variance. Known group analysis revealed a significantly lower composite score in athletes with vs. without a current non-traumatic shoulder injury (56.9±5.8 vs. 62.7±4.5, respectively). A preliminary cut score of 62 was chosen with sensitivity of 85% and specificity of 44%. Composite score inter-rater reliability was excellent ICC _(2,1)=0.94, 95% CI (0.91, 0.96) and item reliability ranged from κ=.57 to 1.00.

CONCLUSIONS

The MSST possesses constructs representative of injury risk and measurement properties acceptable for use in clinical settings. Comprehensive screens with construct validity and known measurement error are needed not only to identify athletes at risk of injury, but also provide an instrument that can be used in studies that seek to validate training approaches proposed to change movement impairment and injury risk in athletes.