Fatigue-related changes in intermuscular electromyographic coherence across rotator cuff and deltoid muscles in individuals with and without subacromial pain.

Neuromuscular fatigue induces superior migration of the humeral head in individuals with subacromial pain. This has been attributed to weakness of rotator cuff muscles and overactive deltoid muscles. Investigation of common inputs to motoneuron pools of the rotator cuff and deltoid muscles offers valuable insight into the underlying mechanisms of neuromuscular control deficits associated with subacromial pain. This study aims to investigate intermuscular coherence across the rotator cuff and deltoid muscles during a sustained submaximal isometric fatiguing contraction in individuals with and without subacromial pain. Twenty symptomatic and 18 asymptomatic young adults participated in this study. Surface electromyogram (EMG) was recorded from the middle deltoid (MD) and infraspinatus (IS). Intramuscular EMG was recorded with fine-wire electrodes in the supraspinatus (SS). Participants performed an isometric fatiguing contraction of 30° scaption at 25% maximum voluntary contraction (MVC) until endurance limit. Pooled coherence of muscle pairs (SS-IS, SS-MD, IS-MD) in the 2-5 Hz (delta), 5-15 Hz (alpha), and 15-35 Hz (beta) frequency bands during the initial and final 30 s of the fatigue task were compared. SS-IS and SS-MD delta-band coherence increased with fatigue in the asymptomatic group but not the symptomatic group. In the alpha and beta bands, SS-IS and SS-MD coherence increased with fatigue in both groups. IS-MD beta-band coherence was greater in the symptomatic than the asymptomatic group. Individuals with subacromial pain failed to increase common drive across rotator cuff and deltoid muscles and have altered control strategies during neuromuscular fatigue. This may contribute to glenohumeral joint instability and subacromial pain experienced by these individuals.NEW & NOTEWORTHY Through the computation of shared neural drive across glenohumeral muscles, this study reveals that individuals with subacromial pain were unable to increase shared neural drive within the rotator cuff and across the supraspinatus and deltoid muscles during neuromuscular fatigue induced by sustained isometric contraction. These deficits in common drive across the shoulder muscles likely contribute to the joint instability and pain experienced by these individuals.

Investigating the brain functional abnormalities underlying pain hypervigilance in chronic neck and shoulder pain: a resting-state fMRI study.

PURPOSE: To investigate pain hypervigilance in individuals suffering from chronic neck and shoulder pain (CNSP) and its underlying brain mechanism. METHODS: The evaluation of pain vigilance was conducted through the utilization of pain vigilance and awareness questionnaires. Voxel-wise regional homogeneity (ReHo) from 60 CNSP patients and 60 healthy controls (HCs) using resting-state fMRI data. Voxel-wise two-sample T-test was conducted to reveal the ReHo variations between CNSP and HC. Correlation analyses were utilized to reveal the connection between brain abnormalities and medical measurements. Furthermore, a mediation analysis was conducted to elucidate the pathway-linking changes in brain function with medical measurements. RESULTS: Our present study revealed three main findings. Firstly, patients with CSNP demonstrated a heightened vigilance of pain in comparison to healthy adults, a common occurrence among individuals with chronic pain conditions. Secondly, we observed brain abnormalities in various brain regions in CSNP patients, and these alterations were associated with the extent of pain vigilance. Lastly, the pain hypervigilance impact on the severity of pain was found to be controlled by regional neural activity in the anterior cingulate cortex (ACC) in subjects with CSNP. CONCLUSION: Our findings suggested that long-term repetitive nociceptive input caused by chronic pain further aggravates the pain intensity by impairing the vigilance-related pain processing within the anterior cingulate cortex in CNSP patients.

The clinical efficacy and safety of platelet-rich plasma on frozen shoulder: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To systematically review the clinical efficacy (pain, function, quality of life) and safety of platelet-rich plasma (PRP) in the treatment of frozen shoulder through meta-analysis, and provide evidence-based medical evidence for the effectiveness of PRP in the treatment of frozen shoulder. METHODS: A search was conducted on international databases (Pubmed, Web of science, Embase) and Chinese databases (CNKI, Wanfang, VIP) to search the clinical studies on the efficacy of platelet-rich plasma in treating frozen shoulder (adhesive capsulitis/periarthritis/50 shoulder) and their corresponding references published from inception until January 2024. Thoroughly excluded literature not meeting the predetermined inclusion criteria, extracted relevant data from the literature, and input it into RevMan5.4 for meta-analysis. RESULTS: This study ultimately included 14 RCTs, with a total of 1024 patients. The results showed that PRP has significant advantages compared with control groups in VAS (mean difference (MD) =-0.38, 95% confidence interval(CI)(-0.73, -0.03), P = 0.03), UCLA (MD = 3.31, 95% CI (1.02,5.60),P = 0.005), DASH (MD = -4.94,95% CI (-9.34, -0.53),P = 0.03), SPADI (SPADI Total: MD =-16.87, 95% CI (-22.84, -10.91), P < 0.00001; SPADI Pain: MD =-5.38, 95% CI (-7.80, -2.97), P < 0.0001; SPADI Disability: MD =-11.00, 95% CI (-13.61,-8.39), P < 0.00001), and the active and passive Range of Motion (active flexion: MD = 12.70, 95% CI (7.44, 17.95), P < 0.00001; passive flexion: MD = 9.47, 95% CI(3.80, 15.14), P = 0.001; active extension: MD = 3.45, 95% CI(2.39, 4.50), P < 0.00001; active abduction: MD = 13.54, 95% CI(8.42, 18.67), P < 0.00001; passive abduction: MD = 14.26, 95% CI (5.97, 22.56), P = 0.0008; active internal rotation: MD = 5.16, 95% CI (1.84, 8.48), P = 0.002; passive internal rotation: MD = 3.65, 95% CI(1.15, 6.15), P = 0.004; active external rotation: MD = 10.50, 95% CI(5.47, 15.53), P < 0.0001; passive external rotation: MD = 6.00, 95% CI (1.82, 10.19), P = 0.005) except passive extension (MD = 2.25, 95% CI (-0.77, 5.28), P = 0.14). In terms of safety, most studies reported no adverse effects, and only one study reported common complications of joint puncture such as swelling and pain after treatment in both PRP and control groups. Previous studies have shown a risk of osteonecrosis caused by corticosteroids. Therefore, the safety of PRP treatment is more reliable. CONCLUSION: The results showed that PRP was more durable and safer than corticosteroids and other control groups in the treatment of frozen shoulder. STUDY DESIGN: Systematic review. TRIAL REGISTRATION: PROSPERO CRD42022359444, date of registration: 22-09-2022.

Measuring myofascial shear strain in chronic shoulder pain with ultrasound shear strain imaging: a case report.

BACKGROUND: Dysfunctional gliding of deep fascia and muscle layers forms the basis of myofascial pain and dysfunction, which can cause chronic shoulder pain. Ultrasound shear strain imaging may offer a non-invasive tool to quantitatively evaluate the extent of muscular dysfunctional gliding and its correlation with pain. This case study is the first to use ultrasound shear strain imaging to report the shear strain between the pectoralis major and minor muscles in shoulders with and without chronic pain. CASE PRESENTATION: The shear strain between the pectoralis major and minor muscles during shoulder rotation in a volunteer with chronic shoulder pain was measured with ultrasound shear strain imaging. The results show that the mean ± standard deviation shear strain was 0.40 ± 0.09 on the affected side, compared to 1.09 ± 0.18 on the unaffected side (p<0.05). The results suggest that myofascial dysfunction may cause the muscles to adhere together thereby reducing shear strain on the affected side. CONCLUSION: Our findings elucidate a potential pathophysiology of myofascial dysfunction in chronic shoulder pain and reveal the potential utility of ultrasound imaging to provide a useful biomarker for shear strain evaluation between the pectoralis major and minor muscles.

Understanding overall shoulder function and health: the value of specific quantitative vs. qualitative shoulder range of motion on patient-reported outcome measures.

HYPOTHESIS AND BACKGROUND: It is known that, though widely used, shoulder range of motion (ROM) measurements are not standardized and have a high rate of intra- and interobserver differences. Particularly, the inconsistency in quantitative and qualitative measurements and their relationship to patient-reported outcome measures (PROMs) make shoulder health difficult to determine. METHODS: This was a prospective study of 147 patients who presented with a chief complaint of shoulder pain to the orthopedic sports medicine and shoulder clinic of a single fellowship-trained surgeon. Measured by 1 examiner, quantitative ROM measurements were taken with a goniometer and qualitative ROM measured by the anatomic level that the patient could reach. The following PROMs were used as well: American Shoulder and Elbow Surgeons shoulder score, Single Assessment Numeric Evaluation, Shoulder Pain and Disability Index, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand questionnaire, 12-Item Short Form Health Survey, and Patient-Reported Outcomes Measurement Information System pain interference short form 6a (PROMIS 6a). Statistical analysis was performed with SPSS using the Pearson correlation and 2-sample t test. The Benjamini-Hochberg correction was used to determine the P value at which statistical significance was reached to correct for multiple comparisons. RESULTS: Qualitative internal rotation (IR) (the hand behind back reach test) and qualitative forward flexion (FF) correlated with all goniometer angle measurements and PROMs (both shoulder and general health scores). These qualitative measures proved to be an appropriate proxy for IR and FF goniometer measurements. Qualitative external rotation (ER) was not a good substitute for quantitative ER measurement. Quantitative ER correlated with all PROMs. As ROM increased when measured by quantitative ER, qualitative IR, and qualitative FF, shoulder and general health PROMs incrementally increased as well. DISCUSSION/CONCLUSIONS: Qualitative IR measurement, the hand-behind-back reach test, is an adequate substitution for IR goniometer angle as well as a strong representation of global shoulder ROM, shoulder health, and general health while factoring in patient age. Qualitative FF measurement is also an appropriate proxy for quantitative FF and represents global shoulder and general health without factoring in age. Quantitative ER, via goniometer angle, is a better assessment of the shoulder than qualitative ER and is a representation of overall shoulder and general health. We recommend the use of quantitative ER, qualitative IR, and qualitative FF measurements to best understand a patient's overall shoulder health and its impact on their overall health.

Relationship between pain and proprioception among individuals with rotator cuff-related shoulder pain.

BACKGROUND: Individuals with rotator cuff-related shoulder pain (RCRSP) have altered proprioception. The relationship between shoulder pain and proprioception is not well understood. PURPOSE: This study aimed to investigate the relationship between shoulder pain and proprioception. STUDY DESIGN: This was a cross-sectional comparative study. METHODS: Twenty-two participants with RCRSP (mean age 27.6 ± 4.8 years) and 22 matched pain-free participants (23.4 ± 2.5 years) performed two upper limb active joint position sense tests: (1) the Upper Limb Proprioception Reaching Test (PRO-Reach; reaching toward seven targets) in centimeters and (2) Biodex System at 90% of maximum internal rotation in degrees. Participants performed three memorization and three reproduction trials blindfolded. The proprioception error (PE) is the difference between the memorized and estimation trials. Pain levels were captured pre- and post-evaluation (11-point Likert Numerical Pain Rating Scale). Relationships between PE and pain were investigated using independent t-tests and Spearman rank correlations. RESULTS: Overall, 22.7% RCRSP participants indicated an increase in pain following the PRO-Reach (X̅ increase of 1.4 ± 1.5 points), while 59% did so with the Biodex (X̅ increase of 2.3 ± 1.8 points), reflecting a clinically important increase in pain. Weak-to-moderate correlations between pain and PEs were found with the Biodex (r = 0.39-0.53) and weak correlations with the PRO-Reach (r = -0.26 to 0.38). Concerning PEs, no significant differences were found between groups with the Biodex (p = 0.32, effect size d = -0.31 [-0.90 to 0.29]). The RCRSP participants demonstrated lower PEs with the PRO-Reach in elevation compared to pain-free participants (global X̅ = 4.6 ± 1.2 cm vs 5.5 ± 1.5 cm; superior 3.8 ± 2.1 cm vs 5.7 ± 2.9 cm; superior-lateral nondominant targets 4.3 ± 2.2 cm vs 6.1 ± 2.8 cm; p = 0.02-0.05, effect size d = 0.72-0.74 [0.12-1.3]). CONCLUSIONS: Individuals with RCRSP demonstrated better upper limb proprioception in elevation, suggesting a change to interoception (sensory reweighting) in the presence of pain.

Evaluation of the Relationship between Acromiohumeral Distance and Supraspinatus Tendon Thickness Measured by Ultrasonography and Rotator Cuff Pathologies, Pain, and Function.

PURPOSE OF THE STUDY: In this study, we aimed to evaluate acromiohumeral distance (AHD) and supraspinatus tendon (ST) thickness measurements and their relationship with pain and function in ST pathologies. MATERIAL AND METHODS: The study included 111 patients and 25 healthy controls (HC). Patients were divided into 3 groups according to their diagnosis: non-tear tendinopathy (NTT), partial thickness tear (PTT), and full thickness tear (FTT). The AHD and ST thickness of the participants were measured with ultrasound. The pain and functional status of the patients were evaluated with the Numeric Rating Scale (NRS), The QuickDASH shortened version of the DASH Outcome Measure - Disabilities of the Arm Shoulder and Hand (QDASH), and Simple Shoulder Test (SST). RESULTS: The AHD value was significantly higher in the NTT group (p=0.000). The AHD value was significantly lower in the FTT group (p=0.000). ST thickness value was significantly lower in the PTT group compared to the NTT group (p=0.000). There was a positive correlation between ST thickness and BMI (r=0.553,p<0.01). There was a negative correlation between ST thickness and SST and a positive correlation between ST thickness (r=-0.223,p<0.05) and QDASH (r=0.276,p<0.05). CONCLUSIONS: We found that AHD and SST thicknesses significantly differed in the NTT, PTT, FTT, and HC groups. This difference may be important for diagnosis. In addition, the effect of obesity on ST thickness and the relationship between ST thickness and functional scores may be considered. Weight control may be effective at this point. KEY WORDS: acromiohumeral distance, supraspinatus tendon thickness, ultrasound.

The Intramuscular Circulation Is Affected by Neck and Shoulder Pain.

The purpose of this study was to investigate the effects of neck and shoulder pain (NSP) and the position of the head and neck on the intramuscular circulation of the cervical muscles such as the trapezius and levator scapulae muscles in young females. Ten NSP subjects (mean age: 20.9 ± 0.5 years) and ten non-NSP subjects (mean age: 20.6 ± 0.7 years) were recruited to this study. Near-infrared spectroscopy (NIRS) was used to non-invasively measure total haemoglobin (Total-Hb), oxygenated haemoglobin (Oxy-Hb), and deoxygenated haemoglobin (Deoxy-Hb) of the trapezius and levator scapulae muscles. The measurements of Total-Hb, Oxy-Hb, and Deoxy-Hb were taken in the neutral position, immediately after the maximally flexed (extended) position, and after 30 s in the maximally flexed (extended) position. In flexion, no significant main effect or interaction was observed with Total-Hb and Oxy-Hb. A significant interaction was observed with Deoxy-Hb (p < 0.01). There was no significant difference in the changes over time in the NSP group (p = 0.91). However, in the non-NSP group, a significant increase was noted at the neutral position to immediately after the maximally flexed position (p < 0.01) and at the end of maintaining the maximally flexed position (p < 0.01). In extension, no significant main effect or interaction was observed with Total-Hb and Oxy-Hb. A significant interaction was observed with Deoxy-Hb (p < 0.01). In the NSP group, no significant difference was observed in the changes over time (p = 0.91). In the non-NSP group, however, a significant decrease was observed from the neutral position to immediately after the maximally extended position (p < 0.01). The results of this study indicate that maintaining either maximal cervical flexion or extension may affect venous blood flow on non-NSP group. However, no effect on NSP group was observed due to existing diminished intramuscular circulation.

Clinical Outcomes of Transcatheter Arterial Embolization for Secondary Stiff Shoulder.

PURPOSE: To assess the clinical outcomes of transcatheter arterial embolization (TAE) for secondary stiff shoulder (SSS). MATERIALS AND METHODS: This is a retrospective analysis of prospectively collected data performed between January 2017 and December 2019. This study comprised 25 patients (20 women and 5 men; median age, 49 years; range 27-59) with SSS resistant to conservative management during at least 3 months. The median time of stiffness was 12 months. The etiology of SSS was postoperative in 14 patients (56%) and posttraumatic in the remaining 11 patients (44%). Periods of immobilization in all patients were associated. TAE was performed, and technical aspects, adverse events, changes for pain, and physical examination before and 6 months after TAE were assessed. RESULTS: Abnormal vessels were observed in 20 of 25 (80%) of the procedures. Transitory cutaneous erythema was noted in 4 patients treated after TAE. Significant differences were observed in the median pain visual analog scale reduction between before and 6 months after TAE (8 vs 2, P < .001). Shoulder mobility significantly improved in both flexion and abduction degrees between before and at 6 months after TAE in (70° vs 150°; P < .001). No symptoms of recurrence appeared. CONCLUSIONS: TAE can result in pain reduction and mobility improvement in patients with SSS refractory to conservative therapy.

Measurement Properties of Isokinetic Dynamometry for Assessment of Shoulder Muscle Strength: A Systematic Review.

OBJECTIVE: To investigate the evidence of measurement properties of isokinetic dynamometry (ID) for assessment of shoulder muscle strength in healthy individuals and patients with nonneurologic shoulder pathology. DATA SOURCES: Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Physiotherapy Evidence Database were searched up to February 2020 without restrictions. Reference lists and citations were hand-searched. STUDY SELECTION: Two review authors independently included studies that met the following criteria: (1) evaluated measurement properties of ID when used on the glenohumeral joint and (2) included individuals 18 years and older. Studies including patients with neurologic, neuromuscular, or systemic diseases or critical illness were excluded. DATA EXTRACTION: The quality assessment and data synthesis were performed according to the COnsensus-based Standards for the selection of health Measurement INstruments methodology. DATA SYNTHESIS: Twenty-one studies with a total of 597 participants were included. The results were combined separately for isometric, concentric, and eccentric test mode; for the velocities 30°/s-60°/s, 90°/s, 120°/s, and 240°/s; for the seated, supine, and standing position; and for internal rotation (IR), external rotation (ER), and the ER/IR ratio. The reliability of ID was overall sufficient with the majority of intraclass correlation coefficients ≥0.70. The quality of evidence was moderate or low for 20 of 30 strata examined. The measurement error results were rated as insufficient for all strata. The SEM ranged from 4%-28%. The quality of evidence varied depending of strata examined. CONCLUSIONS: The reliability of ID for measurement of shoulder strength was overall sufficient for all positions, velocities, and modes of strength. The measurement error was not sufficient. Because most studies used the seated position, the velocities 30°/s-60°/s or 120°/s, and the concentric test mode, the quality of evidence was highest for these conditions.

Shoulder Pain Is Associated With Rate of Rise and Jerk of the Applied Forces During Wheelchair Propulsion in Individuals With Paraplegic Spinal Cord Injury.

OBJECTIVE: To investigate the association between propulsion biomechanics, including variables that describe smoothness of the applied forces, and shoulder pain in individuals with spinal cord injury (SCI). DESIGN: Cross-sectional, observational study. SETTING: Non-university research institution. PARTICIPANTS: Community dwelling, wheelchair dependent participants (N=30) with chronic paraplegia between T2 and L1, with and without shoulder pain (age, 48.6±9.3y; 83% men). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Rate of rise and jerk of applied forces during wheelchair propulsion. Participants were stratified in groups with low, moderate, and high pain based on their Wheelchair User Shoulder Pain Index score on the day of measurement. RESULTS: A mixed-effect multilevel analysis showed that wheelchair users in the high pain group propelled with a significantly greater rate of rise and jerk, measures that describe smoothness of the applied forces, compared with individuals with less or no pain, when controlling for all covariables. CONCLUSIONS: Individuals with severe shoulder pain propelled with less smooth strokes compared to individuals with less or no pain. This supports a possible association between shoulder pain and rate of rise and jerk of the applied forces during wheelchair propulsion.

Effects of Ultrasound-Guided Peritendinous and Intrabursal Corticosteroid Injections on Shoulder Tendon Elasticity: A Post Hoc Analysis of a Randomized Controlled Trial.

OBJECTIVES: The study aimed to investigate whether the shoulder tendons changed their elasticity after ultrasound-guided peritendinous or intrabursal corticosteroid injections. DESIGN: Post hoc secondary analysis of a double-blinded, randomized controlled study with 3 months of follow-up. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Patients with subacromial impingement syndrome (N=60). INTERVENTIONS: Patients with unilateral shoulder pain were randomly assigned to receive standard ultrasound-guided subacromial or dual-target corticosteroid injections. The supraspinatus tendons were exposed to 40 mg triamcinolone acetonide in the formal group, whereas the long head of the biceps brachii tendons (LHBT) and supraspinatus tendons were individually infiltrated by 20 mg triamcinolone acetonide in the latter group. Patients' bilateral shoulders were divided into group 1 (n=30, receiving standard subacromial injections), group 2 (n=30, receiving dual-target injections), and group 3 (n=60, without injections). MAIN OUTCOME MEASURES: Strain ratio of LHBT and supraspinatus tendons using ultrasound elastography. RESULTS: The repeated-measures analysis of variance revealed no intragroup difference of the strain ratio of the LHBT (P=.412 for group 1, P=.936 for group 2, P=.131 for group 3) and supraspinatus tendon (P=.309 for group 1, P=.067 for group 2, P=.860 for group 3) across the 3 time points. Treating group 3 as the reference, the linear mixed model revealed no significant changes in tendon elasticity after either the standard subacromial injection (P=.205 for the LHBT and P=.529 for the supraspinatus tendon) or the dual-target injection (P=.961 for the LHBT and P=.831 for the supraspinatus tendon). CONCLUSIONS: Elasticity of the LHBT and supraspinatus tendons is unlikely to change after a single dose of peritendinous or intrabursal corticosteroid injections. Future studies with a shorter follow-up interval are needed to validate whether corticosteroid injections can cause transient changes of the tendon's elasticity.

Can a metric combining arm elevation and trapezius muscle activity predict neck/shoulder pain? A prospective cohort study in construction and healthcare.

OBJECTIVE: To determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately. METHODS: Dominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0-3). Compositions of working time were determined for arm elevation (< 30°; 30-60°; > 60°), trapezius activity (< 0.5%; 0.5-7.0%; > 7.0%MVE), and a composite metric "neck/shoulder load" (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models. RESULTS: Associations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5-7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (ß = - 0.13; p = 0.037; corresponding to a -0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (ß = - 0.23; p = 0.039) and high (ß = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi. CONCLUSION: The composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.

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.

Shoulder outcome scoring systems have substantial ceiling effects 2 years after arthroscopic rotator cuff repair.

PURPOSE: Previous studies show no difference in clinical outcomes between patients with healed and structurally failed rotator cuff repairs. The objective of this study was to assess ceiling effects when reporting surgical outcomes of arthroscopic rotator cuff repair using four of the currently most popular clinical shoulder outcome scoring systems. METHODS: Ninety-two patients who underwent arthroscopic rotator cuff repair were examined. The simple shoulder test (SST), American Shoulder and Elbow Surgeons (ASES) score, University of California at Los Angeles (UCLA) shoulder rating scale, and Constant-Murley shoulder score were completed 2 years postoperatively. Demographic data of the subjects were analysed using descriptive statistics. The ceiling effects in the outcome data assessed for each scale were estimated based on two previously reported definitions. RESULTS: The number of patients with the maximum possible score was 31 (33.7%) with the SST, 26 (28.3%) with the ASES score, 28 (30.4%) with the UCLA scale, and 18 (19.6%) with the Constant-Murley score. The standardised distance of the outcome data assessed by the SST, ASES score, UCLA scale, and Constant-Murley scores were 0.92, 0.97, 0.96, and 1.18, respectively. CONCLUSION: The SST, ASES score, and UCLA scale evaluated at 2 years postoperatively have substantial ceiling effects showing that the proportion of patients with the maximum possible score is > 20%, and the standardised distance is < 1.0. Researchers should be aware of possible biases due to ceiling effects when interpreting the results of studies investigating the surgical outcomes of arthroscopic rotator cuff repair. It could increase the likelihood of a type II error. LEVEL OF EVIDENCE: IV.

The effect of previous shoulder pain on supraspinatus tendon thickness changes following swimming practice.

OBJECTIVES: To assess if swimming practice results in changes in supraspinatus tendon thickness, acromiohumeral distance, and occupational ratio in shoulders of elite swimmers with and without a history of shoulder pain. DESIGN: Case-Control study. METHODS: A convenience sample of fifty elite swimmers (14-22 years) were recruited for this study. Groups were defined by the presence (history of pain, N = 37) or absence (pain free, N = 63) of significant interfering shoulder pain within the previous 6 months. The current study analyzed supraspinatus tendon thickness, acromiohumeral distance, and the occupational ratio, through the use of ultrasound. Measures were taken prior to swim practice; immediately after practice; and 6 hours post-practice. RESULTS: No statistically significant difference in supraspinatus tendon thickness, acromiohumeral distance or ratio between shoulders with and without a history of pain were found at rest. Following a swimming practice, both shoulders with and without a history of pain had a significant increase in tendon thickness (0.27 & 0.17 mm; P ≤ .001 & <.001). The increase in thickness was significantly greater in the history of pain shoulders compared to pain-free shoulders (P = .003). At 6-hour post-practice, the history of pain shoulders was still significantly thicker than their pre-practice (rested) levels (P = .007). Despite changes in tendon thickness, the occupational ratio remained non-significant between groups. CONCLUSION: Shoulders with a history of pain show an altered response to swimming practice. The results of the current study have implications for training load and injury management. It should prompt investigation into how the tendon reacts under varying load conditions.

The effectiveness of Botulinum Toxin A for treatment of upper limb impairments and dysfunctions in breast cancer survivors: A randomised controlled trial.

OBJECTIVE: To examine the effectiveness of a single Botulinum Toxin A (BTX-A) infiltration in the pectoralis major muscle, in addition to a standard physical therapy (PT) programme on upper limb impairments and dysfunctions after breast cancer treatment. METHODS: Fifty breast cancer patients with persistent pain 3 months after finishing treatment participated in a double-blinded randomised controlled trial. The intervention group received a single BTX-A infiltration. The control group received a placebo (saline) infiltration. Within one week after the infiltration, all patients attended an individual PT programme (12 sessions) during the first 3 months. Outcome parameters were active shoulder range of motion, upper limb strength, scapular statics and shoulder function. Measures were taken before the intervention, at 1, 3 (i.e. after the intervention) and 6 months follow-up. RESULTS: No differences between groups were found for all outcome parameters over the course of 6 months. However, overall beneficial effects of the PT for active forward flexion shoulder range of motion and shoulder function were found in both groups. CONCLUSION: A single Botulinum Toxin A (BTX-A) infiltration in the pectoralis major muscle, in addition to a PT programme cannot be recommended to treat upper limb impairments and dysfunctions after breast cancer treatment.

Effects on shoulder pain and disability of teaching patients with shoulder pain a home-based exercise program: a randomized controlled trial.

OBJECTIVE: To investigate the effect on shoulder pain and disability of teaching patients with shoulder pain how to undertake a home-based exercise program. DESIGN: A randomized controlled trial conducted from September 2015 to January 2016. SETTING: Participants' home. PARTICIPANTS: Sixty participants with shoulder pain who were waiting for physiotherapeutic treatment. INTERVENTIONS: The control group (n = 30) received minimal education about their shoulder condition and instructions to continue their activities as normal. The intervention group (n = 30) received a two-month home exercise program with one-hour sessions delivered by a physiotherapist to begin and one month after the program for exercise instructions. MAIN MEASURES: The primary outcome was change in the Shoulder Pain and Disability Index (SPADI). The secondary outcomes included change in the numeric pain rating scale and medication intake for pain relief. RESULTS: The patients' average age was 54.3 (13.8) years. SPADI scores at baseline were 60.9 (16.5) in the intervention and 64.7 (15.3) in the control group. After two months, the SPADI scores decreased to 18.8 (28.6) and to 61.4 (24.0), respectively, in the intervention and control groups with an estimated mean difference of 40.0, effect size: 1.61. The intervention group showed a reduced pain intensity (estimated mean difference: 3.7, effect size: 2.43) and medication intake (chi-square: 0.001). The number needed to treat was 1.2 for one patient to have a SPADI score <20. CONCLUSION: Teaching patients with shoulder pain how to undertake a home-based exercise program improved shoulder function and reduced pain intensity and medication intake over two months.

Effect of postoperative Trendelenburg position on shoulder pain after gynecological laparoscopic procedures: a randomized clinical trial.

BACKGROUND: Laparoscopic surgery has become a standard of care for many gynecological surgeries due to its lower morbidity, pain and cost compared to open techniques. Unfortunately, the use of carbon dioxide (CO2) to insufflate the abdomen is the main contributor to post-operative shoulder pain. METHODS: We aim to assess the effect of postoperative Trendelenburg position on shoulder pain after gynecological laparoscopic procedures. We hypothesize that maintaining the patient in Trendelenburg for 24 h postoperatively will significantly decrease postoperative shoulder pain and analgesic consumption. After obtaining written informed consent, 108 patients were prospectively randomized into two groups. In the control group, patients underwent standard gynecologic laparoscopic procedures; then after passive deflation of the pneumoperitoneum at the end of the surgery, the patients were placed in supine head up position in the post anesthesia care unit (PACU) and received our institution's common postoperative care. Patients in the intervention group were subjected to the same maneuver but were positioned in a Trendelenburg position (20 °) once fully awake and cooperative in the PACU and retained this position for the first 24 h. Numerical rating scale (NRS) was used to assess shoulder pain and nausea upon patient arrival to the PACU, at 4, 6, 12 (primary outcome) and 24 h postoperatively. Time to first rescue pain medication, total rescue pain medications and overall satisfaction with pain control were recorded. 101 patients were included in the final data analysis. RESULTS: Both groups were comparable in terms of baseline characteristics. NRS pain scores were significantly lower in the intervention group at 12 h compared to the control group (0 [0-1] versus 5 [1-4], p < 0.001), furthermore improvement in postoperative shoulder pain between time of arrival to PACU (time zero) and 12 h postoperatively was significantly higher in patients allocated to the experimental group compared to the control group. Pain scores were significantly lower in patients allocated to the experimental group versus the control group (0 [0-1] versus 5 [1-4], p < 0.001). CONCLUSION: In conclusion, Trendelenburg position is an easy non-pharmacologic intervention that is beneficial in reducing postoperative shoulder pain following gynecologic laparoscopic surgery. TRIAL REGISTRATION: Retrospectively registered at Clinicaltrials.gov, registration number NCT04129385,  date of registration: June 28, 2019.

Different Degree Centrality Changes in the Brain after Acupuncture on Contralateral or Ipsilateral Acupoint in Patients with Chronic Shoulder Pain: A Resting-State fMRI Study.

Chronic shoulder pain (CSP) is the third most common musculoskeletal problem. For maximum treatment effectiveness, most acupuncturists usually choose acupoint in the nonpainful side, to alleviate pain or improve shoulder function. This method is named opposite needling, which means acupuncture points on the right side are selected for diseases on the left side and vice versa. However, the underlying neural mechanisms related to treatment are currently unclear. The purpose of this study was to determine whether different mechanisms were observed with contralateral and ipsilateral acupuncture at Tiaokou (ST 38) in patients with unilateral CSP. Twenty-four patients were randomized to the contralateral acupuncture group (contra-group) and the ipsilateral acupuncture group (ipsi-group). The patients received one acupuncture treatment session at ST 38 on the nonpainful or painful sides, respectively. Before and after acupuncture treatment, they underwent functional magnetic resonance scanning. The treatment-related changes in degree centrality (DC) maps were compared between the two groups. We found alleviated pain and improved shoulder function in both groups, but better shoulder functional improvement was observed in the contra-group. Increased DC in the anterior/paracingulate cortex and decreased DC in bilateral postcentral gyri were found in the contra-group, while decreased DC in the bilateral cerebellum and right thalamus was observed in the ipsi-group. Furthermore, the DC value in the bilateral anterior/paracingulate cortex was positively correlated with the treatment-related change in the Constant-Murley score. The current study reveals different changes of DC patterns after acupuncture at contralateral or ipsilateral ST 38 in patients with CSP. Our findings support the hypothesis of acupoint specificity and provide the evidence for acupuncturists to select acupoints for CSP.