Study protocol subacromial impingement syndrome: the identification of pathophysiologic mechanisms (SISTIM)

Shoulder structures and strength in competitive preadolescent swimmers: A longitudinal ultrasonographic study

BACKGROUND

Repetitive shoulder movements during competitive training may cause changes in the strength of periarticular shoulder structures in preadolescent swimmers.

OBJECTIVE

To prospectively determine the effects of training on shoulder periarticular structures and muscle strength in preadolescent swimmers.

DESIGN

Prospective cohort study.

SETTING

Community-based natatorium.

PARTICIPANTS

Twenty-four preadolescent swimmers aged 10-12 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Measurements were repeated in three periods as preseason, midseason, and postseason. Ultrasonographic measurements (supraspinatus tendon thickness, humeral head cartilage thickness, deltoid muscle thickness, and acromiohumeral distance) were performed using a portable device and a linear probe. Shoulder (flexion, extension, abduction, internal and external rotation) and back (serratus anterior, lower, and middle trapezius) isometric muscle strength were measured with a handheld dynamometer.

RESULTS

Supraspinatus tendon thickness and acromiohumeral distance were similar in all periods (all p > .05); however, deltoid muscle and humeral head cartilage thicknesses increased throughout the season (p = .002, p = .008, respectively). Likewise, whereas shoulder muscle strength increased (all p < .05), back muscle strength was similar in all periods (all p > .05).

CONCLUSIONS

In preadolescent swimmers, acromiohumeral distance and supraspinatus tendon thickness seem to not change; but humeral head cartilage and deltoid muscle thicknesses as well as shoulder muscle strength increase throughout the season.

Effectiveness of proprioceptive neuromuscular facilitation and myofascial release techniques in patients with subacromial impingement syndrome

PURPOSE

To compare the effectiveness of proprioceptive neuromuscular facilitation and myofascial release technique in patients with subacromial impingement syndrome on pain, range of motion, muscle strength, quality of life, functionality and disability.

METHODS

Thirty patients were randomly divided into two groups: proprioceptive neuromuscular facilitation group (n = 15) and proprioceptive neuromuscular facilitation combined with myofascial release technique group (n = 15). Both treatment methods were performed 3 times a week for 4 weeks. Pain severity was assessed by Visuel Analog Scale, range of motion by a goniometer, muscle strength by digital hand dynamometer, quality of life by Nottingham health profile, functionality by arm, shoulder and hand problems questionnaire, disability by shoulder pain and disability index. All measurements were used before and after treatments. Pain severity, range of motion and muscle strength were also evaluated after the first session.

RESULTS

After the treatment, shoulder pain, range of motion, muscle strength, functionality and disability were improved in two groups (p < 0.05). Proprioceptive neuromuscular facilitation showed improvement in pain, whereas myofascial release technique improved pain, physical activity, emotional state, sleep and total dimensions of life quality (p < 0.05). Proprioceptive neuromuscular facilitation was more effective in reducing activity pain, whereas myofascial release technique was more effective in increasing flexion, external and internal rotation range of motion, flexion and abduction muscle strength after the first session (p < 0.05).

CONCLUSIONS

The combined application of proprioceptive neuromuscular facilitation and myofascial release technique has a more acute and cumulative positive effect on pain, range of motion, muscle strength, functionality, disability and quality of life in patients with subacromial impingement syndrome.

Effectiveness of Rehabilitation through Kinematic Analysis of Upper Limb Functioning in Wheelchair Basketball Athletes: A Pilot Study

Wheelchair basketball is one of the most popular Paralympic sports, including players with different diagnoses. To date, there is scarce evidence on shoulder functionality in wheelchair basketball players, and there is no consensus on a shoulder injury prevention program in these athletes. Therefore, in the present pilot study, we aimed to evaluate the effects of a comprehensive rehabilitative approach on shoulder ROM, muscle activity, and functioning in wheelchair basketball athletes. We included adult wheelchair basketball athletes playing in the Italian Second League who completed an 8-week comprehensive rehabilitative program, based on education to avoid upper limb pain injuries, preventive exercises, and improvement of ergonomics through kinematic analysis. We administered the Wheelchair User’s Shoulder Pain Index (WUSPI) and the Kerlan-Jobe Orthopaedic Clinic (KJOC) questionnaire to evaluate pain experienced during functional activities, and used kinematic analysis integrated with sEMG to evaluate shoulder function and propulsion pattern. A sample of 10 wheelchair athletes (33.75 ± 6.42 years) were assessed. After the intervention there was a significant (p < 0.05) difference in WUSPI score (27.0 ± 18.5 vs. 25.0 ± 21.5) and in KJOC score (89.3 ± 10.4 to 95.4 ± 9.1). Moreover, there was a significant improvement in scapular upward rotation, abduction, and extra-rotation of the glenohumeral joint. Propulsion techniques improved in pattern and acceleration. This approach played a key role in improving upper limb function, reducing the incidence of pain and cumulative trauma disorders. However, the small sample size could affect the generalizability of results. In conclusion, healthcare professionals should monitor wheelchair athletes, assessing the patient’s function, ergonomics, equipment, and level of pain, and introducing specific exercises to prevent upper limb injuries.

Pain does not explain reduced teres major co-contraction during abduction in patients with Subacromial Pain Syndrome

BACKGROUND

Patients with Subacromial Pain Syndrome show reduced co-contraction of the teres major during abduction. Consequent insufficient humeral depressor function may contribute to painful irritation of subacromial tissues and offers a potential target for therapy. A crucial gap in knowledge is whether the degree of teres major co-contraction in these patients is influenced by pain itself. To gain insight into this matter, we assessed whether relief of subacromial pain with local analgesics leads to increased adductor co-contraction in 34 patients with subacromial pain.

METHODS

In a single-arm interventional study with 34 patients, electromyographic activity of the latissimus dorsi, pectoralis major, teres major and deltoid was assessed during isometric force tasks in 24 directions before and after subacromial Lidocaine injection. Co-contraction was quantified using the activation ratio; range [-1 (sole antagonistic activation, i.e. co-contraction) to 1 (sole agonistic activation)].

FINDINGS

There were no changes in activation ratio of the teres major after the intervention (Z-score: -0.6, p = 0.569). The activation ratio of the latissimus dorsi increased to 0.38 (quartiles: 0.13-0.76), indicating decreased co-contraction (Z-score: -2.0, p = 0.045).

INTERPRETATION

Subacromial analgesics led to a decrease in co-contraction of the latissimus dorsi, whereas no change in the degree of teres major co-contraction was observed. This study shows that decreased teres major co-contraction in patients with subacromial pain, likely is not the consequence of pain itself, opening a window for physical therapy with training of teres major co-contraction to reduce subacromial irritation and pain.

LEVEL OF EVIDENCE

Level II treatment study.

Reduced psychosocial functioning in subacromial pain syndrome is associated with persistence of complaints after 4 years

BACKGROUND

Patients with subacromial pain syndrome (SAPS) frequently present with coexisting psychosocial problems; however, whether this also associates with long-term outcome is currently unknown. We assessed whether psychosocial functioning in patients with SAPS is associated with persistence of complaints after 4 years of routine care.

METHODS

In a longitudinal study, 34 patients with SAPS were selected after clinical and radiologic evaluation and assessed at baseline and after 4 years. For the assessment of psychosocial functioning, the RAND-36 questionnaire domains of social functioning, role limitations due to emotional problems, mental health, vitality, and general health were evaluated. Complaint persistence at follow-up was assessed by (1) an anchor question (reduced, persistent, or increased symptoms), (2) change in pain (change in visual analog scale score), and (3) change in quality of life (change in Western Ontario Rotator Cuff index score).

RESULTS

Lower baseline mental health (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.85-0.98; P = .013), vitality (OR, 0.90; 95% CI, 0.83-0.98; P = .011), and general health (OR, 0.93; 95% CI, 0.88-0.98; P = .009) were associated with persistent complaints as reported by the anchor question, change in visual analog scale score, and change in Western Ontario Rotator Cuff index score.

CONCLUSIONS

Evaluating psychosocial functioning parallel to physical complaints is currently not standard procedure in the treatment of SAPS. In this study, we showed that factors related to psychosocial functioning are associated with long-term persistence of complaints in SAPS. Future studies may investigate whether a multimodal treatment with assessment of psychosocial functioning may facilitate pain relief and recovery in SAPS.

Reduced force entropy in subacromial pain syndrome: A cross-sectional analysis

BACKGROUND

Generating a force at the hand requires moments about multiple joints by a theoretically infinite number of arm and shoulder muscle force combinations. This allows for learning and adaptation and can possibly be captured using the complexity (entropy) of an isometrically generated force curve. Patients with Subacromial Pain Syndrome have difficulty to explore alternative, pain-avoiding, motor strategies and we questioned whether loss of motor complexity may contribute to this. We assessed whether patients with Subacromial Pain Syndrome have reduced entropy of an isometrically generated abduction and adduction force curve.

METHODS

Forty patients and thirty controls generated submaximal isometric ab- and adduction force at the wrist. The force curve was characterized by the magnitude of force variability [standard deviation and coefficient of variation], and the entropy (complexity) of force variability [approximate entropy].

FINDINGS

Patients showed reduced entropy both during the abduction (-0.16, confidence interval: [-0.33; -0.00], p: 0.048) and adduction task (-0.20, confidence interval: [-0.37; -0.03], p: 0.024) and reduced force variability during abduction (standard deviation: -0.006, confidence interval: [-0.011; -0.001], p: 0.013 and coefficient of variation: -0.51, confidence interval: [-0.93; -0. 10], p: 0.016).

INTERPRETATIONS

Isometric force curves of patients with Subacromial Pain Syndrome show reduced complexity compared to asymptomatic controls, which may indicate more narrow and stereotype use of motor options. In future studies, it should be investigated whether the finding of reduced force (motor) entropy indicates functional decline, contributing to decreased ability to acquire and optimize motor strategies in Subacromial Pain Syndrome.

LEVEL OF EVIDENCE

Level II prognostic study.

Arthroscopic rotator cuff repair with and without subacromial decompression is safe and effective: a clinical study

BACKGROUND

Subacromial decompression, that consists of the release of the coracoid-acromial ligament, subacromial bursectomy and anterior-inferior acromioplasty, has traditionally been performed in the management of this pathology. However, the purpose of subacromial decompression procedure is not clearly explained. Our reaserch aimed to analyse the differences among the outcomes of arthroscopic rotator cuff repair (RCR) made with suture anchors, with or without the subacromial decompression procedure.

METHODS

116 shoulders of 107 patients affected by rotator cuff (RC) tear were treated with Arthroscopic RCR. In 54 subjectes, the arthroscopic RCR and the subacromial decompression procedure (group A) were executed, whereas 53 took only arthroscopic RCR (group B). Clinical outcomes were evaluated through the use of the modified UCLA shoulder rating system, Wolfgang criteria shoulder score and Oxford shoulder score (OSS). Functional outcomes were assessed utilizing active and passive range of motion (ROM) of the shoulder, and muscle strength. The duration of the follow up and the configuration of the acromion were used to realize the comparison between the two groups.

RESULTS

In patients with 2 to 5 year follow up, UCLA score resulted greater in group A patients. In subjectes with longer than five years of follow up, group B patients showed considerably greater UCLA score and OSS if related with group A patients. In subjectes that had the type II acromion, group B patients presented a significant greater strength in external rotation.

CONCLUSION

The long term clinical outcomes resulted significantly higher in patients treated only with RCR respect the ones in patients underwent to RCR with subacromial decompression.

Altered Cocontraction Patterns of Humeral Head Depressors in Patients with Subacromial Pain Syndrome: A Cross-sectional Electromyography Analysis

BACKGROUND

In approximately 29% to 34% of all patients with subacromial pain syndrome (SAPS) there is no anatomic explanation for symptoms, and behavioral aspects and/or central pain mechanisms may play a more important role than previously assumed. A possible behavioral explanation for pain in patients with SAPS is insufficient active depression of the humerus during abduction by the adductor muscles. Although the adductor muscles, specifically the teres major, have the most important contribution to depression of the humerus during abduction, these muscles have not been well studied in patients with SAPS.

QUESTIONS/PURPOSES

Do patients with SAPS have altered contraction patterns of the arm adductors during abduction compared with asymptomatic people?

METHODS

SAPS was defined as nonspecific shoulder pain lasting for longer than 3 months that could not be explained by specific conditions such as calcific tendinitis, full-thickness rotator cuff tears, or symptomatic acromioclavicular arthritis, as assessed with clinical examination, radiographs, and magnetic resonance arthrography. Of 85 patients with SAPS who met the prespecified inclusion criteria, 40 were eligible and agreed to participate in this study. Thirty asymptomatic spouses of patients with musculoskeletal complaints, aged 35 to 60 years, were included; the SAPS and control groups were not different with respect to age, sex, and hand dominance. With electromyography, we assessed the contraction patterns of selected muscles that directly act on the position of the humerus relative to the scapula (the latissimus dorsi, teres major, pectoralis major, and deltoid muscles). Cocontraction was quantified through the activation ratio ([AR]; range, -1 to 1). The AR indicates the task-related degree of antagonist activation relative to the same muscle's degree of agonist activation, equaling 1 in case of sole agonist muscle activation and equaling -1 in case of sole antagonistic activation (cocontraction). We compared the AR between patients with SAPS and asymptomatic controls using linear mixed-model analyses. An effect size of 0.10 < AR < 0.20 was subjectively considered to be a modest effect size.

RESULTS

Patients with SAPS had a 0.11 higher AR of the teres major (95% CI, 0.01-0.21; p = 0.038), a 0.11 lower AR of the pectoralis major (95% CI, -0.18 to -0.04; p = 0.003), and a 0.12 lower AR of the deltoid muscle (95% CI, -0.17 to -0.06; p < 0.001) than control participants did. These differences were considered to be modest. With the numbers available, we found no difference in the AR of the latissimus dorsi between patients with SAPS and controls (difference = 0.05; 95% CI, -0.01 to 0.12; p = 0.120).

CONCLUSIONS

Patients with SAPS showed an altered adductor cocontraction pattern with reduced teres major activation during abduction. The consequent reduction of caudally directed forces on the humerus may lead to repetitive overloading of the subacromial tissues and perpetuate symptoms in patients with SAPS. Physical therapy programs are frequently effective in patients with SAPS, but targeted approaches are lacking. Clinicians and scientists may use the findings of this study to assess if actively training adductor cocontraction in patients with SAPS to unload the subacromial tissues is clinically effective. The efficacy of training protocols may be enhanced by using electromyography monitoring.

LEVEL OF EVIDENCE

Level II, prognostic study.

Therapeutic Interventions for Scapular Kinematics and Disability in Patients With Subacromial Impingement: A Systematic Review

CONTEXT

Impaired scapular kinematics are commonly reported in patients with subacromial impingement syndrome (SIS). Various therapeutic interventions designed to improve scapular kinematics and minimize pain and disability have been described in the literature. However, the short- and long-term benefits of these interventions are unclear.

OBJECTIVE

To determine the effects of specific short- and long-term therapeutic interventions on scapular kinematics and disability in patients with SIS.

DATA SOURCES

We searched PubMed, CINAHL, and SPORTDiscus databases from their origins to January 2018 using a combination of the key words scapular kinematics AND (shoulder dysfunction OR subacromial impingement) and conducted a manual search by reviewing the references of the identified papers.

STUDY SELECTION

Studies were included if (1) preintervention and postintervention measures were available; (2) patient-reported outcomes were reported; (3) scapular kinematics measures at 90° of ascending limb elevation in the scapular plane were included; (4) SIS was diagnosed in participants or participants self-reported symptoms of SIS; (5) they were original clinical studies published in English; and (6) the sample sizes, means, and measure of variability for each group were reported.

DATA EXTRACTION

Seven studies were found. Sample sizes, means, and standard deviations of scapular upward rotation, posterior tilt, and internal rotation at 90° of ascending limb elevation on the scapular plane and the Disabilities of the Arm, Shoulder and Hand scores were extracted.

DATA SYNTHESIS

Standardized mean differences between preintervention and postintervention measures with 95% confidence intervals (CIs) were calculated. We observed that the Disabilities of the Arm, Shoulder and Hand scores improved (mean difference = 0.85; 95% CI = 0.54, 1.16) but did not observe changes in scapular upward rotation (mean difference = -0.04; 95% CI = -0.31, 0.22), posterior tilt (mean difference = -0.09; 95% CI = -0.32, 0.15), or internal rotation (mean difference = 0.06; 95% CI = -0.19, 0.31).

CONCLUSIONS

The short- and long-term therapeutic interventions for SIS improved patient-reported outcomes but not scapular kinematics. The identified improvements in shoulder pain and function were not likely explained by changes in scapular kinematics.

Efficacy of high-intensity laser therapy in subacromial impingement syndrome: a three-month follow-up controlled clinical trial

OBJECTIVES

To evaluate the effectiveness of high-intensity laser therapy on shoulder pain and function in subacromial impingement syndrome.

DESIGN

Clinical controlled trial with alternate allocation.

SETTING

Hospital Department of Rehabilitation.

SUBJECTS

A total of 46 participants with subacromial impingement syndrome.

INTERVENTION

Participants were sequence allocated to an intervention group (high-intensity laser therapy + exercise therapy) and control group (sham-laser + exercise therapy) and received 15 sessions (five days a week during three weeks).

MAIN MEASURES

Patiens were evaluated at baseline, after 15 sessions, and at one month and at three months after completing the intervention. The main outcome variables were pain and functionality as measured by visual analogue scale; pressure pain threshold; Shoulder Pain and Disability Index; Constant-Murley Score; and QuickDASH. Secondary outcomes were number of sessions at discharge and drug use.

RESULTS

A total of 21 patients in high-intensity laser therapy group (56.7 ± 8.9 years) and 22 patients in sham-laser group (61.3 ± 8.9 years) concluded the study. Visual analogue scale (cm) at baseline, one-month, and three-months were 6.2 ± 0.5, 3 ± 2.6, and 2.6 ± 2.4 for the control group and 5.4 ± 1.5, 3.6 ± 1.3, and 1.8 ± 1.7 for experimental group, respectively. Shoulder Pain and Disability Index (points) at baseline, one-month, and three-monts were 51.8 ± 16.1, 16.3 ± 16.1, and 13.6 ± 17.1 in the control group and 41.8 ± 20.6, 20.5 ± 19.7, 11 ± 14.5 in experimental group, respectively. No differences were found between groups ( P > 0.05).

CONCLUSION

The effect of high-intensity laser therapy plus exercise is not higher than exercise alone to reduce pain and improve functionality in patients with subacromial syndrome.

Increased co-contraction of arm adductors is associated with a favorable course in subacromial pain syndrome

BACKGROUND

Enhancement of arm adductor activity during abduction (ie, adductor co-contraction), may be effective in the treatment of subacromial pain syndrome (SAPS). We assessed whether an increase of adductor co-contraction is associated with a favorable course of SAPS.

METHODS

At baseline and after nearly 4 years of follow-up, electromyography of the latissimus dorsi (LD), teres major (TM), pectoralis major, and deltoid muscle was obtained during isometric abduction and adduction tasks in 26 patients with SAPS. Changes in co-contraction were assessed with change in the activation ratio (ΔAR). The AR ranges between -1 and 1, where lower values indicate more co-contraction. Clinical course was determined from an anchor question (reduced, persistent, or increased complaints), the visual analog scale for pain (VAS), and the Western Ontario Rotator Cuff score (WORC).

RESULTS

In patients indicating persistent complaints (31%), the VAS and WORC remained stable. In patients who indicated reduced complaints (69%), the VAS reduced (z score, -3.4; P = .001) and WORC increased (z score, 3.6; P < .001). Unchanged ARs associated with complaints persistence, whereas decreased AR of the LD (ΔAR_LD, -0.21; 95% confidence interval [CI], -0.36 to -0.06) and TM (ΔAR_TM, -0.17; 95% CI, -0.34 to -0.00) coincided with reduced complaints. There was a significant between-group difference in ΔAR_LD (-0.35; 95% CI, -0.60 to 0.10) and ΔAR_TM (-0.36; 95% CI, -0.66 to -0.05).

CONCLUSIONS

Increased co-contraction of the LD and TM is associated with a favorable course of SAPS. This may be explained by widening of the subacromial space accomplished by adductor co-contraction.

POSTURAL ALTERATIONS IN PATIENTS WITH SUBACROMIAL IMPINGEMENT SYNDROME

Background

An aberrant upper body posture has been proposed as one of the etiological factors contributing to the development of subacromial impingement syndrome (SAIS). Clinicians have translated this supposition into assessment and rehabilitation programs despite insufficient and conflicting evidence to support this approach.

Purpose

The purpose of this study was to compare several postural variables between the SAIS patients and asymptomatic healthy controls.

Study Design

Case-Control Study.

Methods

A total of 75 participants including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) participated in the study. Study evaluated several postural variables including forward head posture (FHP), forward shoulder posture (FSP), thoracic kyphosis index (TKI), scapular index (SI), normalized scapular protraction (NSP), and the lateral scapular slide test (LSST). The variables were compared between patient and control groups according to sex.

Results

Significant differences were observed in the female patients compared to asymptomatic controls for the FHP (49.38 + 9.6o vs 55.5o+8.38, p=0.03), FSP (45.58 + 10.1o vs 53.68 + 7.08, p=0.02), and LSST in third position (10.2 + 2.1cm vs 11.5 + 0.7cm, p=0.01). Male patients showed a significant difference only in the FSP compared to controls (61.9o+9.4o vs 49.78 + 9.28, p<0.001).

Conclusions

While inadequate data on the relationship between dysfunctional posture and SAIS has led to broad variations in current rehabilitation strategies, the results of the present study revealed different patterns of postural aberrations in female and male patients with SAIS. This clarifies the need to develop individualized or sex-specific approaches for assessing posture in men and women with SAIS and rehabilitation programs based on the assessment results.

Level of Evidence

3b.

Effects of kinesiotaping added to a rehabilitation programme for patients with rotator cuff tendinopathy: protocol for a single-blind, randomised controlled trial addressing symptoms, functional limitations and underlying deficits

INTRODUCTION

Rotator cuff tendinopathy (RCTe) is the most frequent cause of shoulder pain, resulting in considerable losses to society and public resources. Muscle imbalance and inadequate sensorimotor control are deficits often associated with RCTe. Kinesiotaping (KT) is widely used by clinicians for rehabilitation of RCTe. While previous studies have examined the immediate effects of KT on shoulder injuries or the effects of KT as an isolated method of treatment, no published study has addressed its mid-term and long-term effects when combined with a rehabilitation programme for patients with RCTe. The primary objective of this randomised controlled trial (RCT) will be to assess the efficacy of therapeutic KT, added to a rehabilitation programme, in reducing pain and disabilities in individuals with RCTe. Secondary objectives will look at the effects of KT on the underlying factors involved in shoulder control, such as muscular activity, acromiohumeral distance (AHD) and range of motion (ROM).

METHODS AND ANALYSIS

A single-blind RCT will be conducted. Fifty-two participants, randomly allocated to one of two groups (KT or no-KT), will take part in a 6-week rehabilitation programme. The KT group will receive KT added to the rehabilitation programme, whereas the no-KT group will receive only the rehabilitation programme. Measurements will be taken at baseline, week 3, week 6, week 12 and 6 months. Primary outcomes will be symptoms and functional limitations assessed by the Disabilities of the Arm, Shoulder and Hand questionnaire. Secondary outcomes will include shoulder ROM, AHD at rest and at 60° of abduction, and muscle activation during arm elevation. The added effects of KT will be assessed through a two-way analysis of variance for repeated measures.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of Quebec Rehabilitation Institute of the Centre Integrated University Health and Social Services. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations.

TRIAL REGISTRATION NUMBER

Protocol was registered at ClinicalTrials.gov (NCT02881021) on 25 August 2016. The WHO Trial Registration Data Set can also be found as an online supplementary file.

Blood supply of the subacromial bursa and rotator cuff tendons on the bursal side

PURPOSE

Vascularity of the subacromial bursa and rotator cuff tendons is key factors in the pathogenesis of subacromial bursitis and impingement syndrome, rotator cuff tendinitis, and rotator cuff tears. The purpose of this study was to investigate and describe blood supply to the cranial and caudal parts of the subacromial bursa and the vascularity of the rotator cuff tendons on the bursal side.

METHODS

Fourteen fresh cadaveric shoulders from six females and eight males with a mean age of 71.7 (±10.8) years were studied. Before dissection, an arterial injection of 10% aqueous dispersion of latex was administered. Post-injection, the shoulders were fixed in an alcohol-formalin-glycerol solution.

RESULTS

The cranial and caudal bursa of all specimens was mainly supplied by the thoracoacromial, suprascapular, and anterior and posterior circumflex humeral arteries. The cranial part of the bursa was supplied anteriorly by the thoracoacromial artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third. The caudal part received arterial blood anteriorly from the anterior circumflex humeral artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third of the caudal bursa. In addition, the suprascapular artery branched at the upper surface of the coracohumeral ligament, and the subcoracoid artery branched at the under surface of the same ligament.

CONCLUSION

The subacromial bursa appears well vascularized. The results of the present investigation showed that blood supply to the subacromial bursa at the caudal part and rotator cuff tendons on the bursal side was linked to the same arteries. The subcoracoid artery supplied interval rotator structures close to the caudal bursa. It is the wish of the authors that this meticulous anatomical work will help surgeons in their day-to-day clinical work, e.g. to minimize the risk of complications such as perioperative bleeding.

Electromyographic analysis of rotator cuff muscles in patients with rotator cuff tendinopathy: A systematic review

The shoulder is inherently an unstable joint which heavily relies on the neuromuscular activation of the rotator cuff (RC) complex for stability during movement. Currently, there is no consensus regarding how the activity of RC muscles is affected among individuals with a RC tendinopathy (RCTe). This study reviewed the evidence of studies comparing the electromyographic (EMG) activity of any RC muscle of shoulders with a symptomatic RCTe to asymptomatic shoulders. Eight databases were searched. Data from 343 participants (201 symptomatic and 209 asymptomatic shoulders) were analyzed from 10 out of 402 included studies. Strong evidence for the infraspinatus and supraspinatus during isometric contractions and limited evidence for the supraspinatus and infraspinatus during isokinetic contractions suggest that the muscular activity is not altered among individuals with a RCTe during these types of contraction. Very limited evidence indicates reduced muscle activity for the infraspinatus and subscapularis in the presence of a RCTe during isotonic contractions, and no alterations for the supraspinatus or teres minor were identified. Lastly, conflicting to moderate evidence suggests alterations in RC muscle activity during unrestrained movements and swimming. These findings indicate that EMG deficits associated with a RCTe can best be appreciated during unrestrained movements.

Redefining anterior shoulder impingement: a literature review

Many different types of impingements have been described in the shoulder. Inasmuch as the term 'shoulder impingement' usually refers to subacromial impingement, anterior impingement usually refers to subcoracoid impingement. However, there are many different subtypes of anterior impingements in the shoulder, and awareness of their existence is critical as they vary in their nature and treatment. Recent advances in biomechanical research and arthroscopic exploration of the anterior structures of the shoulder have brought new insights on the various potential impingements, warranting a revision and update of the current definitions of anterior shoulder impingement. The purpose of this article is to propose a comprehensive review and classification of all different subtypes of anterior impingement in the shoulder, including newly described entities.

Effect of Swim Training on the Physical Characteristics of Competitive Adolescent Swimmers

BACKGROUND

Subacromial space distance and forward head and shoulder posture are common characteristics resulting from swim training. These alterations can cause abnormal scapular kinematics and positioning, potentially increasing compression of structures in the subacromial space and increasing the risk for the development of swimmer's shoulder.

PURPOSE

To evaluate the effect of the swim training season on subacromial space distance and forward head and forward shoulder posture as well as to determine the relationship between these variables.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Included in the study were 43 competitive adolescent swimmers and 29 nonoverhead adolescent athletes (controls) who were not currently experiencing any shoulder, neck, or back pain that limited their participation in sports activity. All participants were evaluated 3 times: once before the start of the swim training season and then at 2 follow-up sessions 6 and 12 weeks after the initial testing session. At each testing session, each participant completed a physical examination that included evaluation of posture and subacromial space distance.

RESULTS

Swimmers had significantly greater decreases in subacromial space distance during the training season compared with nonoverhead athletes. Swimmers also demonstrated significantly greater increases in forward shoulder posture compared with nonoverhead athletes. A significant relationship was noted between changes in forward shoulder posture and changes in subacromial space distance from the baseline testing session to the assessment 6 weeks after baseline assessment. As forward shoulder posture increased, subacromial space significantly decreased.

CONCLUSION

Because of their training load, swimmers experience a decrease in subacromial space distance and an increase in forward shoulder posture over the course of 12 weeks of training, potentially making these athletes more vulnerable to the development of shoulder pain and injury.

Subacromial anaesthetics increase asymmetry of scapular kinematics in patients with subacromial pain syndrome

BACKGROUND

Subacromial pain syndrome (SAPS) and scapular dyskinesis are closely associated, but the role of pain is unknown. We hypothesized that pain results in asymmetrical scapular kinematics, and we expected more symmetrical kinematics after infiltration of subacromial anaesthetics.

OBJECTIVE

To investigate the effect of subacromial anaesthetics on scapular kinematics in patients with SAPS.

DESIGN

Observational cohort study.

METHODS

We evaluated shoulder kinematics in 34 patients clinically and radiologically (magnetic resonance arthrography) identified with unilateral SAPS using three-dimensional electromagnetic motion analysis (Flock of Birds). Scapular internal rotation, upward rotation and posterior tilt of the affected shoulder were compared with the kinematics of the unaffected shoulder and following subacromial anaesthetics. Additionally, the association of pain (Visual Analogue Scale, VAS) and scapular rotation was analysed.

RESULTS

Compared with the contralateral healthy shoulder, 5° more (95% CI 0.4-9.7, p = 0.034) scapular internal rotation was observed in the affected shoulder at 110-120° of abduction. Following subacromial anaesthetics in the affected shoulder, internal rotation increased (2°, 95% CI 0.5-3.9, p = 0.045) and posterior tilt decreased (3°, 95% CI 1.5-5.0, p = 0.001) at 110-120° of abduction. Less scapular upward rotation was significantly associated with higher pain scores before infiltration (R = 0.45, p = 0.013).

CONCLUSIONS

More scapular internal rotation was observed in affected shoulders of patients with SAPS compared with unaffected shoulders. Subacromial infiltration did not restore kinematics toward symmetrical scapular motion. These findings suggest that subacromial anaesthesia is not an effective means to instantly restore symmetry of shoulder motion.

Do changes in hand grip strength correlate with shoulder rotator cuff function?

BACKGROUND

Shoulder pain as a result of rotator cuff pathology is one of the most common musculoskeletal complaints presenting within primary care. Assessment of hand grip strength has been proposed as an indicator of rotator cuff function. This experimental study assessed the relationship between grip strength and shoulder lateral rotator muscle strength in a number of different shoulder positions, aiming to investigate whether such a relationship existed and whether grip strength could be used as a functional assessment tool for the posterior cuff.

METHODS

Twenty-seven healthy, physically active, volunteers (19 males, eight females) with no history of shoulder, upper limb or neck injury comprised the study group. The mean (SD) age was 19.8 (5.7) years (range 18 years to 23 years). Grip strength (measured with hand grip dynamometer) and lateral rotator strength (measured with a hand held dynamometer) was measured at neutral, 90° abduction, and 90° abduction with 90° external rotation.

RESULTS

The correlation between grip strength and shoulder lateral rotation strength ranged between r = 0.91 (r (2 )= 0.84) and r = 0.72 (r (2 )= 0.52) across all positions.

CONCLUSIONS

A strong correlation between grip strength and lateral rotator strength was shown at all positions for both left and right hands, suggesting that assessment of grip strength could be used as a rotator cuff monitor of recruitment function.

An evidence-based review of current perceptions with regard to the subacromial space in shoulder impingement syndromes: Is it important and what influences it?

BACKGROUND

Reduction of the subacromial space as a mechanism in the etiology of shoulder impingement syndromes is debated. Although a reduction in this space is associated with shoulder impingement syndromes, it is unclear if this observation is cause or consequence.

METHOD

The purposes of this descriptive review are to provide a broad perspective on the current perceptions with regard to the pathology and pathomechanics of subacromial and internal impingement syndromes, consider the role of the subacromial space in impingement syndromes, describe the intrinsic and extrinsic mechanisms considered to influence the subacromial space, and critique the level of evidence supporting these concepts.

FINDING

Based on the current evidence, the hypothesis that a reduction in subacromial space is an extrinsic cause of impingement syndromes is not conclusively established and the evidence permits no conclusion.

INTERPRETATION

If maintenance of the subacromial space is important in impingement syndromes regardless of whether it is a cause or consequence, research exploring the correlation between biomechanical factors and the subacromial space, using the later as the outcome measure, would be beneficial.

The minimal detectable change of the Constant score in impingement, full-thickness tears, and massive rotator cuff tears

HYPOTHESIS

The purpose of this study was to determine the minimal detectable change (MDC) for the Constant score in patients with impingement, a supraspinatus tear, or a massive rotator cuff (RC) tear as observed changes smaller than the MDC might be the result of measurement error.

METHODS

The Constant score was recorded in a total of 180 patients, including 34 patients with impingement, 105 with supraspinatus tears, and 41 with massive RC tears. We assessed the MDC in the 3 subgroups and total group using the samples standard deviation (SD), internal consistency (Cronbach α), and standard error of the measurement. Floor and ceiling effects were also reported.

RESULTS

The absolute mean Constant score was 72 (SD, 11.2) in the impingement group, 44 (SD, 14.7) in the supraspinatus tear group, and 46 (SD, 18.9) in the massive RC tear group. There were no floor and ceiling effects for the absolute Constant score. In the total group, the internal consistency was 0.8 and the standard error of the measurement was 8. The MDC was 23 points on the Constant score in the total group and 17, 18, and 23 points on the Constant score for impingement, RC tears, and massive RC tears, respectively.

CONCLUSION

This study demonstrates that the MDCs of the Constant score are different in patients with impingement, supraspinatus tears, and massive RC tears. Studies reporting the Constant score should be interpreted by use of the population-specific MDC and minimal clinical important change.

Effects of repetitive shoulder activity on the subacromial space in manual wheelchair users

This study investigated (1) the effect of repetitive weight-relief raises (WR) and shoulder external rotation (ER) on the acromiohumeral distance (AHD) among manual wheelchair users (MWUs) and (2) the relationship between shoulder pain, subject characteristics, and AHD changes. Twenty-three MWUs underwent ultrasound imaging of the nondominant shoulder in an unloaded baseline position and while holding a WR position before and after the WR/ER tasks. Paired t-tests and Spearman correlational analysis were used to assess differences in the AHD before and after each task and the relationships between pain, subject characteristics, and the AHD measures. A significant reduction in the subacromial space (P<0.01) occurred when subjects performed a WR position compared to baseline. Individuals with increased years of disability had greater AHD percentage narrowing after WR (P=0.008). Increased shoulder pain was associated with AHD percentage narrowing after ER (P≤0.007). The results support clinical practice guidelines that recommend MWUs limit WR to preserve shoulder function. The isolated repetitive shoulder activity did not contribute to the changes of subacromial space in MWUs. The ultrasonographic measurement of the AHD may be a target for identifying future interventions that prevent pain.

Low-level laser and local corticosteroid injection in the treatment of subacromial impingement syndrome: a controlled clinical trial

Objective:

To investigate the effectiveness of low-level laser treatment and local corticosteroid injection in patients with subacromial impingement syndrome.

Design:

Controlled clinical trial.

Setting:

Physical Medicine and Rehabilitation outpatient clinic.

Subjects:

One hundred thirty-five patients with subacromial impingement syndrome.

Intervention:

The patients were allocated to three groups: local corticosteroid injection (group I); sham laser treatment (group II); and low-level laser treatment (group III). Low-level laser treatment was performed three times per week for a total of nine sessions. Local corticosteroid injections were administered twice, with an interval of 10 days between each. The patients were assessed at pre-treatment, post-treatment and three and six months after the first visit.

Main measures:

The primary outcome of the study was pain intensity (visual analog scale) during activity and at rest. The secondary outcomes were, shoulder functional status and quality of life measured by the University of California at Los Angeles rating score (UCLA) and Nottingham Health Profile (NHP) scale respectively.

Results:

Significant differences were observed between groups I and II and between groups II and III regarding pain during activity and at rest scores at all of the visits ( p<0.05). Nevertheless, significant improvement was observed between groups I and III regarding pain during activity only at post-treatment ( p=0.013). The UCLA scores were significantly changed in all three study groups at all of the visits ( p<0.05).

Conclusion:

The effectiveness of low-level laser treatment was similar to that of local corticosteroid injection in patients with subacromial impingement syndrome. We concluded that both low-level laser treatment and corticosteroid injection were more effective than sham laser treatment.

The Western Ontario rotator cuff index in rotator cuff disease patients: a comprehensive reliability and responsiveness validation study

BACKGROUND

The Western Ontario rotator cuff index (WORC) is an increasingly applied condition-specific outcome measure for rotator cuff (RC) conditions. However, in most WORC validation studies, only a limited number of psychometric properties are studied in indistinct patient groups.

PURPOSE

To assess psychometric properties of the WORC according to the Scientific Advisory Committee quality criteria for health questionnaires in 3 patient groups with distinct RC conditions.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

The WORC (range, 0-100; 21 items, 5 domains) was administered twice (T1, T2) in 92 patients (35 RC tears, 35 calcific tendinitis, 22 impingement). Additionally, the Constant score (CS) and the Disabilities of the Arm, Shoulder and Hand score (DASH) were recorded. Calcific tendinitis patients were reassessed 6 weeks after treatment with needling and lavage or a subacromial injection with corticosteroids (T3). We assessed floor and ceiling effects, internal consistency, test-retest reliability, precision, construct validity, minimally detectable change, and responsiveness in the diagnostic subgroups and the total group.

RESULTS

Mean age was 55.0 ± 8.7 years, and 49 of 92 (53%) patients were female. Mean baseline WORC was 46.8 ± 20.4, CS was 63.9 ± 15.4, and DASH was 40.9 ± 18.6. Significant differences were found for the CS and DASH between RC tear patients (severe symptoms) and the other patients, but not for the WORC. There were no floor and ceiling effects. Internal consistency was high: the Cronbach alpha coefficient was .95. The intraclass correlation coefficient of .89 and standard error of measurement of 6.9 indicated high reproducibility. Pearson correlations of the WORC with the CS and DASH were .56 and -.65, respectively (both P < .001). At T3, total WORC improved significantly (mean change, 18.8; 95% confidence interval, 11.3-26.2). Correlations of the WORC change scores with CS and DASH changes were .61 and -.84, respectively (both P < .001). Effect size was 0.96, with a standardized response mean of 0.91, indicating good responsiveness.

CONCLUSION

Applied to a variety of RC patients, the WORC had high internal consistency, moderate to good construct validity, high test-retest reliability, and good responsiveness. These findings support the use of the WORC as a condition-specific self-reported outcome measure in RC patients, but its validity in patients with severe symptoms needs further investigation.