Shoulder muscle weakness and proprioceptive impairments in type 2 diabetes mellitus: exploring correlations for improved clinical management.

Background: Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disorder with systemic implications, potentially affecting musculoskeletal health. This study aimed to assess shoulder muscle strength and joint repositioning accuracy in individuals with T2DM, exploring potential correlations and shedding light on the musculoskeletal consequences of the condition. The objectives were two-fold: (1) to assess and compare shoulder strength and joint repositioning accuracy between individuals with T2DM and asymptomatic counterparts, and (2) to examine the correlation between shoulder strength and joint repositioning accuracy in individuals with T2DM. Methods: A cross-sectional study enrolled 172 participants using the convenience sampling method, including 86 individuals with T2DM and an age-matched asymptomatic group (n = 86). Shoulder strength was assessed using a handheld dynamometer, while joint repositioning accuracy was evaluated with an electronic digital inclinometer. Results: Individuals with T2DM exhibited reduced shoulder muscle strength compared to asymptomatic individuals (p < 0.001). Additionally, joint repositioning accuracy was significantly lower in the T2DM group (p < 0.001). Negative correlations were observed between shoulder strength and joint repositioning accuracy in various directions (ranging from -0.29 to -0.46, p < 0.001), indicating that higher muscle strength was associated with improved joint repositioning accuracy in individuals with T2DM. Conclusion: This study highlights the significant impact of T2DM on shoulder muscle strength and joint repositioning accuracy. Reduced strength and impaired accuracy are evident in individuals with T2DM, emphasizing the importance of addressing musculoskeletal aspects in diabetes management. The negative correlations suggest that enhancing shoulder muscle strength may lead to improved joint repositioning accuracy, potentially contributing to enhanced physical functioning in this population.

Physical Factors Associated with Non-Specific Neck Pain: Correlations Among Pain, Disability, Posture, Endurance, and Compensatory Movement.

BACKGROUND This study was conducted to investigate physical risk factors in patients with non-specific neck pain. The correlations among pain intensity, pressure pain threshold, range of motion (ROM), and disability index were analyzed in 50 patients with non-specific neck pain at a hospital in Korea. MATERIAL AND METHODS We enrolled 50 patients diagnosed with non-specific neck pain by a doctor. All subjects were evaluated for pain intensity, pressure threshold, degree of disability, active range of motion (ROM) of the neck, upper cervical rotation ROM, muscular endurance of deep cervical flexor, compensatory movements for neck flexion, forward head posture, shoulder height difference, and rounded shoulder posture. The correlation between each variable was analyzed. RESULTS Pain intensity had a significant correlation between cervical rotation ROM, cervical flexion-rotation ROM, rounded shoulder posture, shoulder height difference, and forward head posture (P<.05). There was a significant correlation between the pressure pain threshold and the cervical extension ROM, cervical flexion-rotation ROM, and rounded shoulder height (P<.05). The disability index had a significant correlation between the cervical rotation ROM, cervical flexion-rotation ROM, rounded shoulder posture, and the compensatory movement of neck flexion (P<.05). CONCLUSIONS Physical risk factors for non-specific neck pain included cervical rotation ROM, upper cervical rotation ROM, rounded shoulder posture, shoulder height difference, and cervical flexion compensatory movements, which can affect pain intensity and pressure pain threshold.

Pool-Based Surfboard Elicits Activation of Posterior Shoulder Muscles During a Surfing Stroke.

ABSTRACT: Pexa, BS, Johnston, CD, Elder, EE, Ford, KR, Patterson, MQ, and Myers, JB. Pool-based surfboard elicits activation of posterior shoulder muscles during a surfing stroke. J Strength Cond Res 38(7): 1300-1304, 2024-Surfboard paddling may activate posterior shoulder muscles, which are critical to baseball pitchers' injury risk and performance. The purpose of this study was to measure posterior shoulder muscle activation during different phases of the surf stroke (propulsion vs. recovery) on a pool-based surfboard. Twenty healthy active adult subjects completed a familiarization and testing session with the pool-based surfboard. During the testing session, electromyography (EMG) sensors were placed on 6 posterior shoulder muscles: latissimus dorsi, infraspinatus, posterior deltoid, upper trapezius, middle trapezius, and lower trapezius. Subjects completed 4 laps in a pool at 3 separate resistances (low, moderate, and heavy) in a randomized order. The peak EMG signal during each phase (propulsion and recovery) was recorded. A 2-way within subject ANOVA (resistance-by-phase) with post hoc Bonferroni's corrections was used to identify differences in EMG activation. There was a significant main effect of phase for the latissimus dorsi (F = 91.3, p < 0.001), upper trapezius (F = 36.5, p < 0.001), middle trapezius (F = 33.8, p < 0.001), and lower trapezius (F = 21.6, p < 0.001). The latissimus dorsi demonstrated higher activation during the propulsion phase (p < 0.001), and all trapezius muscles demonstrated higher activation during the recovery phase (p < 0.001). There was a significant main effect of resistance for the posterior deltoid (F = 3.4, p = 0.043), with higher muscle activation in the low resistance trials compared with the heavy resistance trials (p = 0.036). Recreationally active individuals demonstrate activation of the posterior shoulder when using a pool-based surfboard. This pool-based surfboard may be beneficial to activate the posterior musculature and may be more accessible than standard surfing to baseball athletes.

Evidence of the existence of multiple modules for the stroke-caused flexion synergy from Fugl-Meyer assessment scores.

Stroke-caused synergies may result from the preferential use of the reticulospinal tract (RST) due to damage to the corticospinal tract. The RST branches multiple motoneuron pools across the arm together resulting in gross motor control or abnormal synergies, and accordingly, the controllability of individual muscles decreases. However, it is not clear whether muscles involuntarily activated by abnormal synergy vary depending on the muscles voluntarily activated when motor commands descend through the RST. Studies showed that abnormal synergies may originate from the merging and reweighting of synergies in individuals without neurological deficits. This leads to a hypothesis that those abnormal synergies are still selectively excited depending on the context. In this study, we test this hypothesis, leveraging the Fugl-Meyer assessment that could characterize the neuroanatomical architecture in individuals with a wide range of impairments. We examine the ability to perform an out-of-synergy movement with the flexion synergy caused by either shoulder or elbow loading. The results reveal that about 14% [8/57, 95% confidence interval (5.0%, 23.1%)] of the participants with severe impairment (total Fugl-Meyer score <29) in the chronic phase (6 months after stroke) are able to keep the elbow extended during shoulder loading and keep the shoulder at neutral during elbow loading. Those participants underwent a different course of neural reorganization, which enhanced abnormal synergies in comparison with individuals with mild impairment (P < 0.05). These results provide evidence that separate routes and synergy modules to motoneuron pools across the arm might exist even if the motor command is mediated possibly via the RST.NEW & NOTEWORTHY We demonstrate that abnormal synergies are still selectively excited depending on the context.

Effectiveness of Shoulder Taping in Treating Hemiplegic Shoulder Subluxation: A Randomized Controlled Study of 35 Patients.

BACKGROUND Shoulder subluxation in patients with stroke impairs recovery and quality of life. Kinesiology tape is elastic and water-resistant, is commonly used to prevent musculoskeletal injury, and is increasing in use for rehabilitation of patients requiring neurological or physical rehabilitation. This study included 35 patients with shoulder subluxation following stroke and aimed to compare outcomes from standard physical therapy with and without shoulder kinesiology taping. MATERIAL AND METHODS This randomized controlled study involved 35 participants. The patients were randomized into a shoulder kinesiology taping group (n=18) or sham taping group (n=17). All patients underwent a conventional rehabilitation exercise program 5 days a week for 6 weeks. Half of the patients underwent shoulder kinesiology taping, and the other half underwent sham taping. Pre- and post-assessment scores were recorded for all participants for shoulder subluxation distance (SSD), active range of motion (AROM), visual analog scale (VAS), shoulder pain and disability index (SPADI), and modified Barthel index (MBI). RESULTS After the intervention, SSD, AROM, VAS, SPADI, and MBI improved significantly in the shoulder kinesiology taping and sham taping groups (P<0.05). Also, the shoulder kinesiology taping group showed more effective changes in SSD, AROM, VAS, SPADI, and MBI than the sham taping group (P<0.05). CONCLUSIONS These results suggest that the shoulder kinesiology taping is effective in improving SSD, AROM, VAS, SPADI, and MBI in patients with hemiplegic shoulder subluxation.

Prevalence of impaired foot function in baseball players with and without disabled throwing shoulder/elbow: a case-control study.

Prevalence of impaired foot function among baseball players with and without a disabled throwing shoulder/elbow was investigated. The study included 138 male players. Players who had previously complained of shoulder/elbow pain during throwing motion were defined as the players with a history, and those who experienced shoulder/elbow pain during the examination were defined as having the injury. Foot function was evaluated by foot "rock paper scissors" movements and floating toes. Their prevalence was assessed and the relationships between players with and without the injuries were statistically analyzed. The prevalence of players with a history and injury was 27% and 7%, respectively. The prevalence of impaired foot function on the non-throwing side among players with injury was significantly higher than those without (60% vs. 28%, P < 0.001) and higher tendency on the throwing side than those without (60% vs. 32%). Regarding floating toes, players with a relevant history showed a significantly higher prevalence on the throwing side than those without (49% vs 28%, P < 0.001) and higher tendency on the non-throwing side than those without (49% vs 32%). Players with disabled throwing shoulder/elbow have a significantly higher prevalence of impaired foot function and floating toes than players without it.

Optimizing shoulder elevation assist rate in exoskeletal rehabilitation based on muscular activity indices: a clinical feasibility study.

BACKGROUND: Restoring shoulder function is critical for upper-extremity rehabilitation following a stroke. The complex musculoskeletal anatomy of the shoulder presents a challenge for safely assisting elevation movements through robotic interventions. The level of shoulder elevation assistance in rehabilitation is often based on clinical judgment. There is no standardized method for deriving an optimal level of assistance, underscoring the importance of addressing abnormal movements during shoulder elevation, such as abnormal synergies and compensatory actions. This study aimed to investigate the effectiveness and safety of a newly developed shoulder elevation exoskeleton robot by applying a novel optimization technique derived from the muscle synergy index. METHODS: Twelve chronic stroke participants underwent an intervention consisting of 100 robot-assisted shoulder elevation exercises (10 × 10 times, approximately 40 min) for 10 days (4-5 times/week). The optimal robot assist rate was derived by detecting the change points using the co-contraction index, calculated from electromyogram (EMG) data obtained from the anterior deltoid and biceps brachii muscles during shoulder elevation at the initial evaluation. The primary outcomes were the Fugl-Meyer assessment-upper extremity (FMA-UE) shoulder/elbow/forearm score, kinematic outcomes (maximum angle of voluntary shoulder flexion and elbow flexion ratio during shoulder elevation), and shoulder pain outcomes (pain-free passive shoulder flexion range of motion [ROM] and visual analogue scale for pain severity during shoulder flexion). The effectiveness and safety of robotic therapy were examined using the Wilcoxon signed-rank sum test. RESULTS: All 12 patients completed the procedure without any adverse events. Two participants were excluded from the analysis because the EMG of the biceps brachii was not obtained. Ten participants (five men and five women; mean age: 57.0 [5.5] years; mean FMA-UE total score: 18.7 [10.5] points) showed significant improvement in the FMA-UE shoulder/elbow/forearm score, kinematic outcomes, and pain-free passive shoulder flexion ROM (P < 0.05). The shoulder pain outcomes remained unchanged or improved in all patients. CONCLUSIONS: The study presents a method for deriving the optimal robotic assist rate. Rehabilitation using a shoulder robot based on this derived optimal assist rate showed the possibility of safely improving the upper-extremity function in patients with severe stroke in the chronic phase.

Preoperative handgrip strength can predict early postoperative shoulder function in patients undergoing arthroscopic rotator cuff repair.

BACKGROUND: Rotator cuff tears (RCTs) are a common musculoskeletal disorder, and arthroscopic rotator cuff repair (ARCR) is widely performed for tendon repair. Handgrip strength correlates with rotator cuff function; however, whether preoperative grip strength can predict functional outcomes in patients undergoing ARCR remains unknown. This study aimed to investigate the correlation between preoperative grip strength and postoperative shoulder function following ARCR. METHODS: A total of 52 patients with full-thickness repairable RCTs were prospectively enrolled. Baseline parameters, namely patient characteristics and intraoperative findings, were included for analysis. Postoperative shoulder functional outcomes were assessed using the Quick Disabilities of the Arm, Shoulder, and Hand (QDASH) questionnaire and Constant-Murley scores (CMSs). Patients were followed up and evaluated at three and six months after ARCR. The effects of baseline parameters on postoperative outcomes were measured using generalized estimating equations. RESULTS: At three and six months postoperatively, all clinical outcomes evaluated exhibited significant improvement from baseline following ARCR. Within 6 months postoperatively, higher preoperative grip strength was significantly correlated with higher CMSs (ß = 0.470, p = 0.022), whereas increased numbers of total suture anchors were significantly correlated with decreased CMSs (ß = - 4.361, p = 0.03). Higher body mass index was significantly correlated with higher postoperative QDASH scores (ß = 1.561, p = 0.03) during follow-up. CONCLUSIONS: Higher baseline grip strength predicts more favorable postoperative shoulder function following ARCR. A preoperative grip strength test in orthopedic clinics may serve as a predictor for postoperative shoulder functional recovery in patients undergoing ARCR.

Shoulder balance in Lenke type 2 adolescent idiopathic scoliosis: correlations among radiological indices, cosmetic indices, and patient-reported outcomes.

OBJECTIVE: The aim of this study was to investigate the correlation between radiological indices of shoulder balance (SB) and cosmetic indices of shoulder deformity in patients with Lenke type 2 adolescent idiopathic scoliosis (AIS) and to determine the extent to which patient-reported outcomes (PROs) correlate with these measurements. Current management decisions and outcomes for SB in AIS are primarily based on radiological measurements. It is crucial to understand how these radiological parameters and cosmetic indices relate to patient satisfaction. METHODS: The authors analyzed the preoperative radiological and photographic indices of SB, along with PROs, in patients with Lenke type 2 AIS. Lateral SB parameters included the radiological shoulder height (RSH) and clavicle angle, while medial SB parameters included the first rib angle and T1 tilt angle. Photographic indices included the shoulder height angle (SHA), axilla height angle (AHA), and the left/right trapezius angle (LRTA) ratio. The authors assessed the self-image, mental health, and total score domains of the Korean version of the 22-item Scoliosis Research Society questionnaire. RESULTS: In their analysis of Lenke type 2 patients, the authors found that correlation coefficients between radiological measurements and photographic indices ranged from -0.25 to 0.47, among which only lateral SB including clavicle angle and RSH showed a significant correlation with anterior and posterior photographic indices. No statistically significant correlations were found between radiological measurements and PROs. Anterior photographic indices including SHA and AHA significantly correlated with all three PROs (p < 0.05). CONCLUSIONS: Radiological shoulder parameters did not accurately reflect the perceived SB. Anterior photographic indices were reliable for evaluating clinical SB in patients with Lenke type 2 AIS and correlated with PROs. Spine surgeons may benefit from paying more attention to anterior photographic indices when making surgical decisions regarding clinical SB.

Anterior vertebral body tethering shows clinically comparable shoulder balance outcomes to posterior spinal fusion.

PURPOSE: Posterior spinal fusion (PSF) is the current gold standard in surgical treatment for adolescent idiopathic scoliosis. Vertebral body tethering (VBT) is a fusionless alternative. Shoulder balance is an important metric for outcomes and patient satisfaction. Here we compare shoulder balance outcomes between PSF and VBT. METHODS: In this retrospective review, the pre-operative and post-operative absolute radiographic shoulder height (|RSH|) of 45 PSF patients were compared to 46 VBT patients. Mean values were compared and then collapsed into discrete groups (|RSH| GROUP) and compared. Patients were propensity score matched. Regression models based on pretest-posttest designs were used to compare procedure type on post-operative outcomes. RESULTS: Pre-operatively there were no differences in |RSH| between PSF and VBT, however, at latest post-operative follow-up PSF maintained a larger |RSH| imbalance compared to VBT (0.91 cm vs 0.63 cm, p = 0.021). In an ANCOVA regression, PSF was associated with a larger |RSH| imbalance compared to VBT, F(1, 88) = 5.76, p = 0.019. An ordinal logistic regression found that the odds ratio of being in a worse |RSH| GROUP for PSF vs VBT is 2.788 (95% CI = 1.099 to 7.075), a statistically significant effect χ2(1) = 4.658, p = 0.031. Results were similar in subgroup analyses of Lenke 1 and Lenke 2 patients, though to less statistical significance. CONCLUSION: While PSF was found to be associated with worse |RSH| outcomes, the actual numbers (2-3 mm) are unlikely to be clinically meaningful. Thus, in this analysis, VBT can be said to show comparable shoulder balance outcomes to PSF.

Effects of shoulder brace usage on postural stability in stroke survivors: A pilot randomized controlled trial.

BACKGROUND: Despite advances in stroke rehabilitation, challenges in upper limb motor recovery and postural stability persist, negatively affecting overall well-being. Arm slings and shoulder braces have been proposed to address these issues, but their efficacy in promoting postural stability remains unclear. OBJECTIVE: This pilot randomized controlled study aimed to evaluate the impact of a new shoulder brace (N1-Neurosling) on trunk postural stability during walking, pain, and upper limb muscle strength in chronic stroke survivors. METHODS: Twenty-four adult chronic stroke patients were involved and randomly assigned to the shoulder brace group (SBg) or control group (CTRLg). Were assessed at baseline (T0) and after 4 weeks (T1) through the Trunk Control Test, the Numerical Rating Scale, the Motricity Index, Manual Muscle Test, and instrumental wearable-based assessment. RESULTS: After 4 weeks, the SBg showed significant improvement in Trunk Control Test scores (p = 0.020) and smoothness of gait measured by log dimensionless jerk along the Antero-Posterior axis (- 5.31±0.25 vs. - 5.18±0.27, p = 0.018) compared to the CTRLg. The SBg also demonstrated a reduction in pain in the shoulder girdle and enhanced upper limb muscle strength. CONCLUSION: The use of the N1-Neurosling shoulder brace led to improvements in postural stability and smoothness of gait in stroke patients.

Detection of Cutibacterium acnes in Tissue Samples from Clean Primary Shoulder Surgeries - Part II / Detecção de Cutibacterium acnes em amostras de tecidos de cirurgias limpas primárias do ombro - Parte II

Abstract Objective Research and identification of Cutibacterium acnes (C. acnes) and other microorganisms in deeptissue samples collected in clean shoulder surgeries of patients who did not undergo any previous invasive joint procedure and who had no clinical history of infection. Methods We analyzed the results of cultures of intraoperative deep tissue samples from 84 patients submitted to primary clean shoulder surgery. Tubes containing culture medium were used for storage and transport of anaerobic agents, prolonged incubation time, and mass spectrometer for diagnosis of bacterial agents. Results Bacteria growth was evidenced in 34 patients (40.4%) of the 84 included in the study. Of these, 23 had growth of C. acnes in at least one sample of deep tissue collected, corresponding to 27.3% of the total patients. The second most common agent was Staphylococcus epidermidis, present in 7.2% of the total individuals included. We showed a higher relationship between sample positivity and males, a lower mean age, absence of diabetes mellitus, ASA I score, and antibiotic prophylaxis in anesthetic induction with cefuroxime. Conclusions A high percentage of isolates of different bacteria was found in shoulder tissue samples of patients undergoing clean and primary surgeries, who had no history of previous infection. Identification of C. acnes was high (27.6%), and Staphylococcus epidermidis was the second most frequent agent (7.2%).

Resumo Objetivo Pesquisa e identificação de Cutibacterium acnes (C. acnes) e de outros microrganismos em amostras de tecidos profundos coletados em cirurgias limpas de ombro em pacientes que não foram submetidos a nenhum procedimento invasivo articular prévio e que não possuíam antecedentes clínicos de infecção. Métodos Foram analisados os resultados das culturas de amostras de tecidos profundos intraoperatórias de 84 pacientes submetidos à cirurgia limpa primária do ombro. Foram utilizados tubos contendo meio de cultivo para armazenamento e transporte de agentes anaeróbicos, tempo prolongado de incubação e espectrômetro de massa para diagnósticos de agentes bacterianos. Resultados Foi evidenciado o crescimento de bactérias em 34 pacientes (40,4%) dos 84 incluídos no estudo. Desses, 23 apresentavam crescimento de C. acnes em pelo menos uma amostra de tecido profundo coletada, correspondendo a 27,3% do total de pacientes. O segundo agente mais encontrado foi o Staphylococcus epidermidis, presente em 7,2% do total de indivíduos incluídos. Evidenciamos maior relação da positividade de amostras com o gênero masculino, uma média de idade inferior, a ausência de diabetes mellitus, o escore ASA I e a profilaxia antibiótica na indução anestésica com cefuroxima. Conclusões Verificou-se um elevado percentual de isolados de diferentes bactérias em amostras de tecidos de ombros de pacientes submetidos a cirurgias limpas e primárias e sem histórico de infecção anterior. A identificação de C. acnes foi elevada (27,6%) e o Staphylococcus epidermidis foi o segundo agente mais frequente (7,2%).

Reverse Shoulder Arthroplasty: Evaluation of the Clinical and Functional Outcomes per Etiology / Artroplastia reversa de ombro: Avaliação dos resultados clínicos e funcionais de acordo com a etiologia

Abstract Objective The present study aimed to evaluate the clinical outcomes of reverse shoulder arthroplasty to treat several conditions. Methods Retrospective, longitudinal study analyzing the Constant and University of California at Los Angeles (UCLA) scores and range of motion of patients undergoing reverse shoulder arthroplasty. Results In total, 28 patients were analyzed, with a mean age of 75.6 years old. The mean duration of follow-up was 45 months. Overall, there was a significant variation (p< 0.0001) between the preoperative (10.2 points) and the postoperative UCLA scores (29.6 points), corresponding to a relative increase of approximately 200%. In addition, the mean Constant score was 67.8, and the complication rate was 17.8%. As for functional outcomes per etiology, fracture sequelae cases presented the best mean elevation (165°), Constant score (79 points), postoperative UCLA score (32.5 points), and absolute delta UCLA score increase (22 points), but with no statistical significance. However, cases operated for fracture sequelae showed significantly higher elevation (p= 0.027) and Constant score (p= 0.047) compared to rotator cuff arthropathy cases. In addition, the lowest mean postoperative Constant and UCLA scores were observed for the following etiologies: primary arthrosis, acute fracture, and arthroplasty revision. Conclusion Reverse shoulder arthroplasty showed satisfactory functional outcomes and may be a treatment option not only for rotator cuff arthropathy but for several other conditions.

Resumo Objetivo Avaliar os resultados clínicos da artroplastia reversa do ombro no tratamento de suas diversas indicações. Métodos Estudo longitudinal retrospectivo que analisou os resultados dos escores Constant, UCLA e amplitudes de movimentos dos pacientes submetidos à artroplastia reversa do ombro. Resultados Foram analisados 28 pacientes, a média de idade foi de 75.6 anos, com seguimento médio de 45 meses. No geral, obtivemos uma variação significativa (p< 0,0001) entre o escore UCLA pré-operatório (10,2 pontos) e o escore UCLA pós-operatório (29,6 pontos), o que corresponde a um aumento relativo de aproximadamente 200%. Além disso, obtivemos pontuação média do escore Constant de 67,8 e uma taxa de complicações de 17,8%. Quanto aos resultados funcionais segundo as indicações, os casos de sequela de fratura apresentaram as melhores médias de elevação (165°), escore Constant (79 pontos), escore UCLA pós-operatório (32,5 pontos) e aumento absoluto na variação do escore UCLA (22 pontos), sem significância estatística. Porém, identificou-se que os casos operados por sequela de fratura apresentaram elevação (p= 0,027) e pontuação no escore Constant (p= 0,047) significativamente maiores em relação aos casos de artropatia do manguito rotador. Além disso, observamos que as menores médias dos escores Constant e UCLA pós-operatórios foram obtidos nas seguintes etiologias: artrose primária, fratura aguda e revisão de artroplastia. Conclusão A artroplastia reversa de ombro apresentou resultados funcionais satisfatórios, podendo ser uma opção de tratamento não somente nos casos de artropatia do manguito rotador, mas também em várias outras patologias.

Causes of Shoulder Dysfunction in Diabetic Patients: A Review of Literature.

Objective: Understanding the underlying mechanisms behind shoulder dysfunctions in patients with diabetes mellitus. Study Design: Systematic qualitative literature review. Participants: Patients with shoulder dysfunctions and diagnosed with impaired glucose tolerance or diabetes mellitus. Intervention: Published scientific literature containing evidence about the mechanisms of shoulder dysfunctions in the diabetic population. Articles were selected based on criteria containing diabetic population, shoulder dysfunction, methodological quality ≥ 6/9 and >20 subjects. Main Outcome measures: range of motion; questionnaires (QoL, UCLA-m, SPADI, DASH); blood glucose, blood HbA1C; calculated capsular stiffness (Kcap); calcification shoulder joint; shoulder dysfunction in patients with glucose metabolism disorders and diabetes mellitus. Results: We found 17 published articles with level 2 and 3 evidence. Multiple factors such as age, duration of diabetes mellitus (DM), glycated hemoglobin (HbA1c), advanced glycation end products (AGE), vascular endothelial growth factor (VEGF), interleukin-1ß (IL-1ß) were shown to be associated with tendon changes and increased capsular stiffness (Kcap) conceivably leading to limited range of motion (ROM) or frozen shoulder. Decreased ROM and frozen shoulder have a significantly higher prevalence in DM than in non-DM. Conclusions: Based on the current literature we confirm a high prevalence of shoulder dysfunctions in patients with diabetes mellitus. The cause of the shoulder complications is unknown, and more research is mandatory to shed more light on the complex interplay between the multifactorial causes of shoulder dysfunction in diabetes mellitus.

Risk for Shoulder Conditions After Vaccination: A Population-Based Study Using Real-World Data.

BACKGROUND: Although shoulder conditions have been reported as an adverse event after intramuscular vaccination in the deltoid muscle, epidemiologic data on shoulder conditions after vaccination are limited. OBJECTIVE: To estimate the risk for shoulder conditions after vaccination and assess possible risk factors. DESIGN: Retrospective cohort study. SETTING: Kaiser Permanente Southern California, a large integrated health care organization. PARTICIPANTS: Kaiser Permanente Southern California members aged 3 years or older who had an intramuscular vaccination administered in the deltoid muscle between 1 April 2016 and 31 December 2017. MEASUREMENTS: A natural language processing (NLP) algorithm was used to identify potential shoulder conditions among vaccinated persons with shoulder disorder diagnosis codes. All NLP-identified cases were manually chart confirmed on the basis of our case definition. The characteristics of vaccinated persons with and without shoulder conditions were compared. RESULTS: Among 3 758 764 administered vaccinations, 371 cases of shoulder condition were identified, with an estimated incidence of 0.99 (95% CI, 0.89 to 1.09) per 10 000 vaccinations. The incidence was 1.22 (CI, 1.10 to 1.35) for the adult (aged ≥18 years) and 0.05 (CI, 0.02 to 0.14) for the pediatric (aged 3 to 17 years) vaccinated populations. In the adult vaccinated population, advanced age, female sex, an increased number of outpatient visits in the 6 months before vaccination, lower Charlson Comorbidity Index, and pneumococcal conjugate vaccine were associated with a higher risk for shoulder conditions. Among influenza vaccines, quadrivalent vaccines were associated with an increased risk for shoulder conditions. Simultaneous administration of vaccines was associated with a higher risk for shoulder conditions among elderly persons. LIMITATION: Generalizability to other health care settings, use of administrative data, and residual confounding. CONCLUSION: These population-based data suggest a small absolute risk for shoulder conditions after vaccination. Given the high burden of shoulder conditions, clinicians should pay attention to any factors that may further increase risks. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention.

The reserve of joint torque determines movement coordination.

Humans coordinate biomechanical degrees of freedom to perform tasks at minimum cost. When reaching a target from a seated position, the trunk-arm-forearm coordination moves the hand to the well-defined spatial goal, while typically minimising hand jerk and trunk motion. However, due to fatigue or stroke, people visibly move the trunk more, and it is unclear what cost can account for this. Here we show that people recruit their trunk when the torque at the shoulder is too close to the maximum. We asked 26 healthy participants to reach a target while seated and we found that the trunk contribution to hand displacement increases from 11 to 27% when an additional load is handled. By flexing and rotating the trunk, participants spontaneously increase the reserve of anti-gravitational torque at the shoulder from 25 to 40% of maximal voluntary torque. Our findings provide hints on how to include the reserve of torque in the cost function of optimal control models of human coordination in healthy fatigued persons or in stroke victims.

Changes in shoulder outcomes using ultrasonographic assessment of breast cancer survivors: a prospective longitudinal study with 6-month follow-up.

This study aimed to describe changes in supraspinatus tendon thickness, acromiohumeral distance, and the presence of fluid in the subacromial bursa as measured by ultrasound, as well as shoulder range of motion and strength, perceived shoulder disability, and health-related quality of life in women before and after breast cancer treatment. Women who underwent surgery for unilateral breast cancer who did not suffer from shoulder pain or difficulty performing activities of daily living in the 6 months prior to surgery were included. One pre-surgical (A0) and three post-surgical assessments at 7-10 days (A1), 3 months (A2), and 6 months (A3) after surgery were carried out. The thickness of the supraspinatus tendon on the affected side decreased between post-surgical (A1) and 6-month (A3) follow-up assessments (p = 0.029), although the minimal detectable change was not reached. The active range of motion of the affected shoulder decreased after surgery. Strength changes were observed in both shoulders after surgery. The intensity of shoulder pain increased between post-surgical and 6-month follow-up assessments. Shoulder function was decreased at the post-surgical assessment and increased throughout the follow-ups. Health-related quality of life declined after surgery. A trend of decreasing thickness of the supraspinatus tendon of the affected shoulder was observed. Detecting these possible structural changes early would allow for early or preventive treatment.

Self-reported arm and shoulder problems in breast cancer survivors in Sub-Saharan Africa: the African Breast Cancer-Disparities in Outcomes cohort study.

BACKGROUND: Arm and shoulder problems (ASP), including lymphedema, were common among women with breast cancer in high-income countries before sentinel lymph node biopsy became the standard of care. Although ASP impair quality of life, as they affect daily life activities, their frequency and determinants in Sub-Saharan Africa remain unclear. METHODS: All women newly diagnosed with breast cancer at the Namibian, Ugandan, Nigerian, and Zambian sites of the African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort study were included. At each 3-month follow-up interview, women answered the EORTC-QLQ-Br23 questionnaire, including three ASP items: shoulder/arm pain, arm stiffness, and arm/hand swelling. We estimated the cumulative incidence of first self-reported ASP, overall and stratified by study and treatment status, with deaths treated as competing events. To identify determinants of ASP, we estimated cause-specific hazard ratios using Cox models stratified by study site. RESULTS: Among 1476 women, up to 4 years after diagnosis, 43% (95% CI 40-46), 36% (33-38) and 23% (20-25), respectively, self-reported having experienced arm/shoulder pain, stiffness and arm/hand swelling at least once. Although risks of self-reported ASP differed between sites, a more advanced breast cancer stage at diagnosis, having a lower socioeconomic position and receiving treatment increased the risk of reporting an ASP. CONCLUSION: ASP are very common in breast cancer survivors in Sub-Saharan Africa. They are influenced by different factors than those observed in high-income countries. There is a need to raise awareness and improve management of ASP within the African setting.