搜索结果：Shoulder & elbow

This paper presents Funabot-Upper, a wearable haptic suit that enables users to perceive 14 upper-body motions, including those of the trunk, shoulder, elbow, and wrist. Inducing kinesthetic perception through wearable haptic devices has attracted attention, and various devices have been developed in the past. However, these have been limited to verifications on single body parts, and few have applied the same method to multiple body parts as well. In our previous study, we developed a technology that uses the contraction of artificial muscles to deform clothing in three dimensions. Using this technology, we developed a haptic suit that induces kinesthetic perception of 7 motions in multiple upper body. However, perceptual mixing caused by stimulating multiple human muscles has occurred between the shoulder and the elbow. In this paper, we established a new, simplified design policy and developed a novel haptic suit that induces kinesthetic perceptions in the trunk, shoulder, elbow, and wrist by stimulating joints and muscles independently. We experimentally demonstrated the induced kinesthetic perception and examined the relationship between stimulation and perceived kinesthetic p

This paper presents a novel rehabilitation robot designed to address the challenges of Passive Range of Motion (PROM) exercises for frozen shoulder patients by integrating advanced scapulohumeral rhythm stabilization. Frozen shoulder is characterized by limited glenohumeral motion and disrupted scapulohumeral rhythm, with therapist-assisted interventions being highly effective for restoring normal shoulder function. While existing robotic solutions replicate natural shoulder biomechanics, they lack the ability to stabilize compensatory movements, such as shoulder shrugging, which are critical for effective rehabilitation. Our proposed device features a 6 Degrees of Freedom (DoF) mechanism, including 5 DoF for shoulder motion and an innovative 1 DoF Joint press for scapular stabilization. The robot employs a personalized two-phase operation: recording normal shoulder movement patterns from the unaffected side and applying them to guide the affected side. Experimental results demonstrated the robot's ability to replicate recorded motion patterns with high precision, with Root Mean Square Error (RMSE) values consistently below 1 degree. In simulated frozen shoulder conditions, the rob

BACKGROUND: Outcomes assessment after the treatment of shoulder disorders has involved the use of various condition-specific outcome instruments. The purpose of this study was to determine the psychometric properties of the American Shoulder and Elbow Surgeons subjective shoulder scale in patients with shoulder instability, rotator cuff disease, and glenohumeral arthritis. METHODS: Test-retest reliability, internal consistency, content validity, criterion validity, construct validity, and responsiveness to change were determined for the American Shoulder and Elbow Surgeons shoulder scale within subsets of an overall study population of 455 patients with shoulder instability, 474 patients with rotator cuff disease, and 137 patients with glenohumeral arthritis. RESULTS: There was acceptable test-retest reliability for the overall American Shoulder and Elbow Surgeons shoulder scale (intraclass correlation coefficient = 0.94) and ten of eleven domains. There was acceptable internal consistency for patients with instability (Cronbach alpha = 0.61), rotator cuff disease (0.64), and arthritis (0.62). There were acceptable floor and ceiling effects for patients with instability (0% and 1.3%, respectively), rotator cuff disease (0% for both), and arthritis (0% for both). There was acceptable and appropriate criterion validity, with significant correlations (p < 0.05) between the overall American Shoulder and Elbow Surgeons scale and the physical functioning, role-physical, and bodily pain domains of the Short Form-12 scale, and nonsignificant correlations (p > 0.05) with the role-emotional, mental health, vitality, and social function domains. There was acceptable construct validity, with all twenty-three hypotheses demonstrating significance (p < 0.05), and acceptable responsiveness to change for patients with instability (standardized response mean, 0.93), rotator cuff disease (1.16), and arthritis (1.11). CONCLUSIONS: The use of outcome instruments with psychometric properties that have been vigorously established is essential. The American Shoulder and Elbow Surgeons subjective shoulder scale demonstrated overall acceptable psychometric performance for outcomes assessment in patients with shoulder instability, rotator cuff disease, and glenohumeral arthritis.

K-means clustering is an unsupervised clustering method that requires an initial decision of number of clusters. One method to determine the number of clusters is the elbow method, a heuristic method that relies on visual representation. The method uses the number based on the elbow point, the point closest to 90 degrees that indicates the most optimum number of clusters. This research improves the elbow method such that it becomes an objective method. We use the analytical geometric formula to calculate an angle between lines and real analysis principle of derivative to simplify the elbow point determination. We also consider every possibility of the elbow method graph behaviour such that the algorithm is universally applicable. The result is that the elbow point can be measured precisely with a simple algorithm that does not involve complex functions or calculations. This improved method gives an alternative of more reliable cluster determination method that contributes to more optimum k-means clustering.

Portable pneumatic systems for 2 degree-of-freedom (DOF) soft shoulder exosuits remain underexplored, and face fundamental trade-offs between torque output and dynamic response that are further compounded by the need for multiple actuators to support complex shoulder movement. This work addresses these constraints through a volume-optimized spindle-shaped angled actuator (SSAA) geometry: by reducing actuator volume by 35.7% (357mL vs. 555mL), the SSAA maintains 94.2% of output torque while achieving 35.2% faster dynamic response compared to uniform cylindrical designs. Building on the SSAA, we develop a curved abduction actuator (CAA) based on the SSAA geometry and a horizontal adduction actuator (HAA) based on the pouch motor principle, integrating both into a dual-DOF textile-based shoulder exosuit (390 g). The exosuit delivers multi-modal assistance spanning shoulder abduction, flexion, and horizontal adduction, depending on the actuation. User studies with 10 healthy participants reveal that the exosuit substantially reduces electromyographic (EMG) activity across both shoulder abduction and flexion tasks. For abduction with HAA only, the exosuit achieved up to 59% muscle activ

BACKGROUND: The American Shoulder and Elbow Surgeons (ASES) questionnaire was developed to provide a standardized method for evaluating shoulder function. Previous studies have determined the clinical responsiveness of this outcome measure for heterogenous populations or patients with nonoperatively treated rotator cuff disease. Currently, to our knowledge, no studies exist that establish the clinically relevant change in the ASES score after shoulder arthroplasty. QUESTIONS/PURPOSES: We asked: (1) What are the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for the ASES score after primary and reverse shoulder arthroplasties? (2) Are the MCID and SCB for the ASES score different between primary and reverse shoulder arthroplasties? (3) What patient-related factors are associated with achieving the MCID and SCB after total shoulder arthroplasty and reverse shoulder arthroplasty? METHODS: A longitudinally maintained institutional shoulder arthroplasty registry was retrospectively queried for patients who underwent primary shoulder arthroplasty, including anatomic or reverse total shoulder arthroplasty from 2007 to 2013, with a minimum 2-year followup. Seven hundred ninety-four patients were identified and eligible; 304 of these patients did not have 2 years of followup or complete datasets, resulting in a study cohort of 490 patients (62% of the 794 potentially eligible). The MCID and SCB of the ASES score for these patients was calculated using an anchor-based method, using four different anchors measuring satisfaction with work, activities, overall, and activity from the SF-36. The MCID (anchored to somewhat satisfied) and SCB (very satisfied) of the ASES score were calculated for the entire cohort and stratified by arthroplasty type. Multivariate logistic regression of patient-related factors that influence the MCID and SCB achievement was performed. RESULTS: The MCID for all patients combined ranged from 6.3 to 13.5; for the overall satisfaction anchor, the MCID was 13.5 ± 4.5 (95% CI, 4.8-22.3). The SCB for the overall cohort ranged from 12.0 to 36.6; for the overall satisfaction anchor, the SCB was 36.6 ± 3.8 (95% CI, 29.1-44.1). There were no differences in the MCID of the ASES score between anatomic and reverse shoulder arthroplasty for any of the anchors (p = 0.159-0.992) or the SCB for any of the anchors (p = 0.467-0.977). Combining anatomic and reverse shoulder arthroplasty in one group, higher preoperative ASES score (odds ratio [OR], 0.96; 95% CI, 0.94-0.98; p < 0.001), having a reverse shoulder arthroplasty (OR, 0.36; 95% CI, 0.16-0.85; p = 0.016), and having rheumatoid arthritis were independent predictors of not achieving an MCID for the ASES 2 years after surgery. Higher preoperative ASES score (OR, 0.91; 95% CI, 0.89-0.92; p < 0.001), a diagnosis of rotator cuff tear arthropathy (OR, 0.14; 95% CI, 0.07-0.30; p < 0.001), a diagnosis of back pain (OR, 0.42; 95% CI, 0.24-0.71); p = 0.002), and living alone (OR, 0.36; 95% CI, 0.19-0.69; p = 0.002) were all independent predictors of not achieving SCB after shoulder arthroplasty. CONCLUSIONS: Patients with glenohumeral arthritis or rotator cuff tear arthropathy who undergo primary conventional total or reverse shoulder arthroplasty and have at least a nine-point improvement in their ASES score experience a clinically important change, whereas those who have at least a 23-point improvement in their ASES score experience a substantial clinical benefit. High preoperative function was associated with a decreased likelihood of achieving clinically important change after total shoulder arthroplasty. LEVEL OF EVIDENCE: Level III, therapeutic study.

Mixture-of-Experts (MoE) models enable model scaling while maintaining low inference-time compute by activating only a subset of experts per token. However, conventional routing relies on a fixed top-k selection, forcing the model to spend the same compute regardless of how many experts are relevant. We introduce elbow-based routing, a training-free inference-time modification that dynamically adjusts the number of experts on a per-token basis. Our method examines the sorted router probability distribution and identifies an elbow point that separates high- and low-probability experts. We find that most router distributions exhibit clear inflection points suitable for this strategy, and we show both theoretically and empirically that elbow-based routing preserves expert load balance. Experiments on a state-of-the-art MoE model demonstrate an average latency reduction of 5.3% while maintaining accuracy across six benchmarks.

This paper presents a comprehensive analysis of the contact force profile of a single-cell bidirectional soft pneumatic actuator, specifically designed to aid in the abduction and adduction of the shoulder for pediatric exosuits. The actuator was embedded in an infant-scale test rig featuring two degrees of freedom: an actuated revolute joint supporting shoulder abduction/adduction and a passive (but lockable) revolute joint supporting elbow flexion/extension. Integrated load cells and an encoder within the rig were used to measure the force applied by the actuator and the shoulder joint angle, respectively. The actuator's performance was evaluated under various anchoring points and elbow joint angles. Experimental results demonstrate that optimal performance, characterized by maximum range of motion and minimal force applied on the torso and upper arm, can be achieved when the actuator is anchored at two-thirds the length of the upper arm, with the elbow joint positioned at a 90-degree angle. The force versus pressure and joint angle graphs reveal nonlinear and hysteresis behaviors. The findings of this study yield insights about optimal anchoring points and elbow angles to minimi

Despite advances in upper-limb (UL) prosthetic design, achieving intuitive control of intermediate joints - such as the wrist and elbow - remains challenging, particularly for continuous and velocity-modulated movements. We introduce a novel movement-based control paradigm entitled Compensation Effect Amplification Control (CEAC) that leverages users' trunk flexion and extension as input for controlling prosthetic elbow velocity. Considering that the trunk can be both a functional and compensatory joint when performing upper-limb actions, CEAC amplifies the natural coupling between trunk and prosthesis while introducing a controlled delay that allows users to modulate both the position and velocity of the prosthetic joint. We evaluated CEAC in a generic drawing task performed by twelve able-bodied participants using a supernumerary prosthesis with an active elbow. Additionally a multiple-target-reaching task was performed by a subset of ten participants. Results demonstrate task performances comparable to those obtained with natural arm movements, even when gesture velocity or drawing size were varied, while maintaining ergonomic trunk postures. Analysis revealed that CEAC effectiv

Shoulder surfing has been studied extensively, however, it remains unexplored whether and how it impacts users. Understanding this is important as it determines whether shoulder surfing poses a significant concern and, if so, how best to address it. By surveying smartphone users in the UK, we explore how shoulder surfing impacts a) the privacy perceptions of victim users and b) their interaction with smartphones. We found that the impact of being shoulder surfed is highly individual. It is perceived as unavoidable and frequently occurring, leading to increased time for task completion. Individuals are concerned for their own and other peoples privacy, seeing shoulder surfing as a gateway to more serious threats like identity or device theft. Participants expressed a willingness to alter their behaviour and use software based protective measures to prevent shoulder surfing, yet, this comes with a set of user defined criteria, such as effectiveness, affordability, reliability, and availability. We discuss future work directions for user-centred shoulder surfing mitigation.

International standards for biometric identity documents mandate strict compliance with pose requirements, including the square presentation of a subject's shoulders. However, the literature on automated quality assessment offers few quantitative methods for evaluating this specific attribute. This paper proposes a Shoulder Presentation Evaluation (SPE) algorithm to address this gap. The method quantifies shoulder yaw and roll using only the 3D coordinates of two shoulder landmarks provided by common pose estimation frameworks. The algorithm was evaluated on a dataset of 121 portrait images. The resulting SPE scores demonstrated a strong Pearson correlation (r approx. 0.80) with human-assigned labels. An analysis of the metric's filtering performance, using an adapted Error-versus-Discard methodology, confirmed its utility in identifying non-compliant samples. The proposed algorithm is a viable lightweight tool for automated compliance checking in enrolment systems.

A common challenge in home-based rehabilitation is muscle compensation induced by pain or fatigue, where patients with weakened primary muscles recruit secondary muscle groups to assist their movement, causing issues such as delayed rehabilitation progress or risk of further injury. In a home-based setting, the subtle compensatory actions may not be perceived since physiotherapists cannot directly observe patients. To address this problem, this study develops a novel wearable strain sensor-based shoulder patch to detect fatigue-induced muscle compensation during bicep curl exercises. Built on an observation that the amplitude of a strain sensor's resistance is correlated to the motion of a joint that the sensor is attached to, we develop an algorithm that can robustly detect the state when significant changes appear in the shoulder joint motion, which indicates fatigue-induced muscle compensation in bicep curls. The developed shoulder patch is tested on 13 subjects who perform bicep curl exercises with a 5 kg dumbbell until reaching fatigue. During the experiment, the performance of the shoulder patch is also benchmarked with optical tracking sensors and surface electromyography (s

Beam intercepting devices rely on cooling systems to effectively dissipate the thermal energy generated during the impact of a high-energy beam. Regardless of the device's size, integrating the cooling system is a complex task, particularly when the resulting device is only a few centimetres in size, as is the case with the positron source target for the Future Circular Collider at CERN, where the current design consists of a tungsten core with two embedded tantalum cooling tubes. Due to the reduced dimensions of the chosen tantalum tubes (OD6.35xID4.35 mm), the selected manufacturing method is compression bending. The present study develops and evaluates a numerical model to manufacture the required elbow. The methodology is divided in four steps: i) minium allowable bending radius calculation, ii) material constitutive law validation, iii) prediction of the resulting distortion due to ovalization and iv) experimental validation via (non) destructive methods. The results indicate that a minimum bending radius of 10 mm is suitable for manufacturing the elbow. The distortion caused by ovalization is within +-0.5 mm, resulting in an important deviation respect to the nominal geometry

Background: Shoulder fractures are often underdiagnosed, especially in emergency and high-volume clinical settings. Studies report up to 10% of such fractures may be missed by radiologists. AI-driven tools offer a scalable way to assist early detection and reduce diagnostic delays. We address this gap through a dedicated AI system for shoulder radiographs. Methods: We developed a multi-model deep learning system using 10,000 annotated shoulder X-rays. Architectures include Faster R-CNN (ResNet50-FPN, ResNeXt), EfficientDet, and RF-DETR. To enhance detection, we applied bounding box and classification-level ensemble techniques such as Soft-NMS, WBF, and NMW fusion. Results: The NMW ensemble achieved 95.5% accuracy and an F1-score of 0.9610, outperforming individual models across all key metrics. It demonstrated strong recall and localization precision, confirming its effectiveness for clinical fracture detection in shoulder X-rays. Conclusion: The results show ensemble-based AI can reliably detect shoulder fractures in radiographs with high clinical relevance. The model's accuracy and deployment readiness position it well for integration into real-time diagnostic workflows. The curr

Moving the arm is complicated by mechanical interactions that arise between limb segments. Such intersegmental dynamics cause torques applied at one joint to produce movement at multiple joints, and in turn, the only way to create single joint movement is by applying torques at multiple joints. We investigated whether the nervous system accounts for intersegmental limb dynamics across the shoulder, elbow, and wrist joints during self-initiated planar reaching and when countering external mechanical perturbations. Our first experiment tested whether the timing and amplitude of shoulder muscle activity account for interaction torques produced during single-joint elbow movements from different elbow initial orientations and over a range of movement speeds. We found that shoulder muscle activity reliably preceded movement onset and elbow agonist activity, and was scaled to compensate for the magnitude of interaction torques arising because of forearm rotation. Our second experiment tested whether elbow muscles compensate for interaction torques introduced by single-joint wrist movements. We found that elbow muscle activity preceded movement onset and wrist agonist muscle activity, and thus the nervous system predicted interaction torques arising because of hand rotation. Our third and fourth experiments tested whether shoulder muscles compensate for interaction torques introduced by different hand orientations during self-initiated elbow movements and to counter mechanical perturbations that caused pure elbow motion. We found that the nervous system predicted the amplitude and direction of interaction torques, appropriately scaling the amplitude of shoulder muscle activity during self-initiated elbow movements and rapid feedback control. Taken together, our results demonstrate that the nervous system robustly accounts for intersegmental dynamics and that the process is similar across the proximal to distal musculature of the arm as well as between feedforward (i.e., self-initiated) and feedback (i.e., reflexive) control. NEW &amp; NOTEWORTHY Intersegmental dynamics complicate the mapping between applied joint torques and the resulting joint motions. We provide evidence that the nervous system robustly predicts these intersegmental limb dynamics across the shoulder, elbow, and wrist joints during reaching and when countering external perturbations.

This study focuses on the rotation of the hips and shoulders during a baseball bat swing, analyzing the time-series changes in rotational angles, rotational velocities, and axes using marker position data obtained from a motion capture system with 12 infrared cameras. Previous studies have examined factors such as ground reaction forces, muscle activation patterns, rotational energy, angular velocity, and angles during a swing. However, to the best of our knowledge, the hip and shoulder rotational motions have not been adequately visualized or compared. In particular, there is a lack of analysis regarding the coordination and timing differences between hip and shoulder movements during the swing. Therefore, this study aims to quantitatively compare the hip and shoulder rotational movements during the swing between skilled and unskilled players and visualizes the differences between them. Based on the obtained data, the study aims to improve the understanding of bat swing mechanics by visualizing the coordinated body movements during the swing.

Recent analyses of mm-wavelength protoplanetary disk observations have revealed several emission excesses on the previously identified dust rings, referred to as dust shoulders. The prevalence of dust shoulders suggests that they trace a common but unclear mechanism. In this work, we combine 3D, multifluid hydrodynamic simulations with radiative transfer calculations to explain the formation of dust shoulders. We find that the ring-shoulder pairs can result from the 3D planet-disk interactions with massive, gap-opening planets. The key driver is the dust filtration effect at the local pressure maximum due to planet-driven outward gas flows. Our work provides a possible explanation for the outer dust shoulders in recent super-resolution analyses of ALMA observations. It also provides insights into the formation of the inner dust shoulder in the PDS 70 disk and highlights the role of 3D effects in planet-disk interaction studies.

Ultrasound imaging of the medial elbow is crucial for the early diagnosis of Ulnar Collateral Ligament (UCL) injuries. Specifically, measuring the elbow joint space in ultrasound images is used to assess the valgus instability of the elbow caused by UCL injuries. To automate this measurement, a model trained on a precisely annotated dataset is necessary; however, no publicly available dataset exists to date. This study introduces a novel ultrasound medial elbow dataset to measure the joint space. The dataset comprises 4,201 medial elbow ultrasound images from 22 subjects, with landmark annotations on the humerus and ulna, based on the expertise of three orthopedic surgeons. We evaluated joint space measurement methods on our proposed dataset using heatmap-based, regression-based, and token-based landmark detection methods. While heatmap-based landmark detection methods generally achieve high accuracy, they sometimes produce multiple peaks on a heatmap, leading to incorrect detection. To mitigate this issue and enhance landmark localization, we propose Shape Subspace (SS) landmark refinement by measuring geometrical similarities between the detected and reference landmark positions.

BACKGROUND: The overhead throwing athlete has unique range of motion characteristics of the shoulder and elbow. Numerous theories exist to explain these characteristics; however, the precise cause is not known. Although it is accepted that range of motion is altered, the acute effect of baseball pitching on shoulder and elbow range of motion has not been established. HYPOTHESIS: There will be a reduction in passive range of motion immediately after baseball pitching. STUDY DESIGN: Controlled laboratory study. METHODS: Sixty-seven asymptomatic male professional baseball pitchers participated in the study. Passive range of motion measurements were recorded using a customized bubble goniometer for shoulder external rotation, shoulder internal rotation, total shoulder rotational motion, elbow flexion, and elbow extension on the dominant and nondominant arms. Testing was performed on the first day of spring training. Measurements were taken before, immediately after, and 24 hours after pitching. RESULTS: A significant decrease in shoulder internal rotation (-9.5 degrees), total motion (-10.7 degrees), and elbow extension (-3.2 degrees) occurred immediately after baseball pitching in the dominant shoulder (P<.001). These changes continued to exist 24 hours after pitching. No differences were noted on the nondominant side. CONCLUSION: Passive range of motion is significantly decreased immediately after baseball pitching. This decrease in range of motion continues to be present 24 hours after throwing. High levels of eccentric muscle activity have previously been observed in the shoulder external rotators and elbow flexors during pitching. These eccentric muscle contractions may contribute to acute musculotendinous adaptations and altered range of motion. The results of this study may suggest a newly defined mechanism to range of motion adaptations in the overhead throwing athlete resulting from acute musculoskeletal adaptations, in addition to potential osseous and capsular adaptations.