To provide a video tutorial on assessment and diagnosis of canine elbow dysplasia and treatment with extracorporeal shockwave therapy. Dogs undergoing shockwave therapy for therapeutic purpose. Assess the patient through gait analysis and examination. Elbow discomfort is investigated with diagnostic imaging (CT scan or orthogonal radiographs) to confirm a diagnosis of elbow dysplasia and secondary osteoarthritis. Prepare the elbow for treatment by shaving the hair over the target anatomy, cleaning the skin with 70% isopropyl alcohol, and applying coupling gel. Select appropriate shockwave settings and standoff for the patient. Position the trode perpendicular to the medial elbow joint and deliver the treatment while slowly moving the trode over the medial humeral epicondyle, medial coronoid process, and medial joint capsule attachments. Repeat the process on the lateral aspect of the elbow. The treatment can be repeated in the contralateral elbow if indicated. Record treatment including the number of shocks delivered and energy flux density in mJ/mm2. Shockwave therapy can be prescribed as a series of 3 treatments followed by reassessment. Assessment after a treatment series is necessary to quantify response to the therapy and determine whether treatment should be continued. Shockwave therapy is a noninvasive therapy that causes the release of growth factors and anti-inflammatory cytokines that improve analgesia and encourage better healing. Shockwave is a simple noninvasive therapeutic option for management of secondary elbow osteoarthritis. With appropriate diagnosis of the underlying condition, shockwave can be easily applied to the target anatomy for maximal analgesic effect and functional improvement.

Numerous lineages of theropod dinosaurs display notable modification of the forelimb, particularly reduction in size and number of digits. Alvarezsauroids are one of the most striking examples of this, exhibiting extreme shortening and increased robusticity of forelimb elements, with a functionally monodactylous manus in late-diverging taxa. These features are generally interpreted as adaptations for digging, possibly as part of a myrmecophagous ecology. Here, we test this hypothesis, using computational range of motion analysis of the shoulder and elbow joints to demonstrate the feasibility of digging behaviours in Mononykus olecranus, a highly specialized alvarezsauroid, and the less specialized Bannykus wulatensis. We find that Bannykus has the capacity for various digging styles and generalized forelimb function, while Mononykus has more restricted motion and may have employed a highly specialized digging style. We also identify similarities in forelimb muscle moment arms between alvarezsaurs and specialized mammalian diggers, supporting adaptation for digging. These findings are consistent with interpretations of insectivory in alvarezsauroids, and suggest increasing specialization to myrmecophagy throughout their evolutionary history, shedding new light on the evolution of this enigmatic clade and the ecological diversity of non-avian theropod dinosaurs.

Arthroscopy of the elbow joint is usually performed with a 30° view. Stability tests, structural assessments and pathologies are described with this scope. Due to the anatomy of the distal humerus and the arthroscopic accessibility, the assessment of the capitellum, particularly with regard to cartilage damage, is limited in terms of dimension and depth. Arthroscopy with flexible optics in the range of 15° to 90° has not been routinely performed. The aim of the study was to investigate whether the use of flexible optics offers advantages in the assessment of the capitellum. Eleven fresh-frozen human cadaveric elbows were examined in a standardized free-hanging position with the elbow flexed to 90°. Arthroscopy was performed through the proximal posterolateral portal using a rigid 30° arthroscope and a flexible 15°-90° arthroscope. The most anterior visible margin of the capitellar articular surface was identified and marked arthroscopically for each optic. Following open surgical dislocation of the elbow, the distance between the two markings was measured in millimeters. Paired comparisons were performed using a paired t-test, and effect size was calculated using Cohen's d. In all specimens, the flexible 15°-90° arthroscope provided greater anterior visualization of the capitellum compared with the 30° arthroscope. The mean additional visible distance was 7.0 ± 2.5mm (95% CI 5.3-8.7mm). This difference was statistically significant (p < 0.001) with a large effect size (Cohen's d = 2.654). A flexible 15°-90° arthroscope significantly increased anterior visualization of the capitellum compared with a conventional 30° arthroscope in this cadaveric model. Whether this anatomical visualization gain translates into clinical diagnostic or therapeutic benefit requires further investigation.

BackgroundApproximately 70% of survivors of stroke have problems with arm function. Physiotherapists assess arm functional range of motion (ROM) using either a goniometer or functional questionnaires, which lack objective accuracy and require a skilled physiotherapist. We developed the Track-UL algorithm based on a markerless motion capture system to measure arm ROM.ObjectiveThis study aimed to measure the agreement between our novel Track-UL algorithm and Kinovea software in assessing arm ROM during functional tasks in the laboratory and home settings.MethodsVideos were recorded while 27 survivors of chronic stroke performed 4 functional tasks (forward reaching, arm abduction, moving the hand toward the mouth, and moving the hand toward the head) in the laboratory and at home. The videos were analyzed by 2 independent raters using the Track-UL algorithm and Kinovea software. The limits of agreement and intraclass correlation coefficients were calculated.ResultsWe found no clinically significant systematic bias in shoulder and elbow angle, with good agreement between the Track-UL algorithm and Kinovea software (assessed via Bland-Altman plots). The 95% limits of agreement were –3.18 to 6.41 degrees for the shoulder joint and −5.35 to 8.78 degrees for the elbow joint in the laboratory setting, and –6.21 to 3.62 degrees for the shoulder joint and −4.06 to 2.53 degrees for the elbow joint in the home setting. There was excellent absolute agreement between the measurement tools across all tasks and joints; intraclass correlation coefficient values ranged from 0.97 (95% CI 0.97-0.99) to 0.99 (95% CI 0.99-0.99; P<.001 for both laboratory and home measurements).ConclusionsThe novel Track-UL algorithm is an accurate, valid, and easy tool that can be used to assess upper-limb ROM in survivors of stroke at clinics and potentially at home. This will support physiotherapists in remotely monitoring and adapting rehabilitation programs.

ABSTRACT Objectives To evaluate whether 100 consecutive pitches induce clinically meaningful increases in medial elbow joint space gap (MJS) in high school baseball players and to examine associations with player characteristics, including early multi-sport participation. Methods In a randomized controlled trial, 34 healthy male high school baseball players were allocated to a pitching group (n = 17) or a control group (n = 17). The pitching group threw 100 fastballs at maximal effort, whereas controls rested for an equivalent duration. MJS was measured by ultrasonography before and after pitching or rest. The minimal clinically important difference (MCID) for MJS change (mm and %) was calculated using a distribution-based method (0.5 × SD of the pitching group’s MJS increase). Group × time effects were tested using a two-way repeated-measures ANOVA, and univariate analyses explored relationships between MJS change and participant characteristics. Results No significant group × time interaction was observed (p = 0.427). In the pitching group, MJS increased by 0.2 ± 1.1 mm (8.3 ± 24.6%), remaining below the MCID thresholds (0.55 mm; 12.3%). Early multi-sport experience during elementary school was associated with smaller MJS expansion (p = 0.009), and the number of non-baseball sports correlated negatively with MJS change (r = −0.628, p = 0.007). No associations were found with pitch velocity or body composition. Conclusion A single bout of 100 pitches did not produce clinically meaningful MJS widening in high school baseball players. However, early multi-sport participation was related to reduced MJS expansion, suggesting that diversified sport experience may be an important background factor when refining pitch-count guidance.

Inspired by the "brick-and-mortar" architecture of pearl oyster shells, a novel high-strength, highly conductive, and environmentally friendly hydrogel was fabricated via photopolymerization employing a dual-network design and solvent-exchange strategy. The resulting poly(vinyl alcohol) (PVA)/acrylic acid (AA)/gelatin (Gel)/tannic acid (TA)/quaternary ammonium chitosan (HACC) @ acetylene black (AB) (PAGTH-AB) composite hydrogel exhibits a tensile strength of 5.49 MPa, an elongation at break of 736%, a toughness of 22.07 MJ/m3, a Young's modulus of 0.69 MPa, and an electrical conductivity of 0.83 S/m, along with excellent freeze resistance, water retention, and long-term stability. As a flexible sensor, the hydrogel demonstrates a linear response over a broad strain range (0-500%), outstanding cyclic stability (2000 cycles), and a rapid dynamic response (336 ms). Even under frigid conditions, it enables real-time, precise monitoring of human motions such as finger, wrist, elbow, and knee joint movements, as well as gesture changes, and enables the accurate capture of dynamic writing trajectories. This work presents a novel and effective strategy for designing high-performance resilient hydrogels, offering a promising route for developing flexible electronic sensors with high strength and stability.

Relation between forearm flexor–pronator muscle elasticity and ulnar collateral ligament laxity of the elbow joint in high school pitchers with and without medial elbow tenderness: evaluation using shear wave elastography

BackgroundThe shoulder and elbow differ in their anatomical structure and physiological function, which can lead to differences in joint position sense (JPS) accuracy. However, most previous studies have assessed JPS in single-joint motions across multiple planes.ObjectiveThis study aimed to compare the joint position error (JPE) between single- and multi-joint motions and investigate how motion patterns and planes of motion influence proprioceptive accuracy.MethodsThe single-joint motion involved flexion of either the shoulder or elbow to a target angle of 45° without reference. The multi-joint motion included simultaneous shoulder and elbow flexion (SF-EF) and shoulder abduction with elbow flexion (SA-EF).ResultsIn the single-joint motion, the shoulder exhibited a lower JPE and higher reliability than those of the elbow. In multi-joint motions within the same plane (SF-EF), the shoulder JPE increased significantly, whereas in multi-joint motions across different planes (SA-EF), the JPE decreased.ConclusionIn single-joint motions, the shoulder has superior proprioceptive acuity compared to the elbow, which may be attributed to differences in peripheral sensory mechanisms and segment-based motor control within the central nervous system. In multi-joint motions, proprioceptive distortion owing to summation effects was observed in a single plane, but not in multiple planes.

Design and performance analysis of flexible wrist and elbow joint actuators for upper limb exoskeleton rehabilitation robot

Perforator flap reconstruction for post-burn flexion contracture of the elbow joint.

Anatomy and biomechanics of the elbow joint

To investigate the clinical efficacy of ultrasound in the treatment of supracondylar fractures of humerus in children complicated with nerve injury. Between January 2019 and January 2022, a total of 21 patients of supracondylar fracture of humerus in children with nerve injury underwent ultrasound-guided treatment. The patients ranged in age from 2 to 10 years old and included 13 boys and 8 girls. Of these patients, 13 were associated with radial nerve injury, 6 with median nerve injury, and 2 with ulnar nerve injury. Preoperative ultrasonography was used to evaluate nerve injury. According to the classification proposed by ZHU et al., typeⅠand typeⅡ fractures are treated with closed reduction and percutaneous Kirschner wire internal fixation, while type Ⅶ fractures require open exploration to assess nerve injury. The recovery of nerve function was evaluated according to the trial standard for the assessment of peripheral nerve function in the upper limb. The postoperative elbow joint function was evaluated using the Flynn score. All 21 patients were followed up for a period ranging from 6 to 12 months, fracture healing time ranged from 4 to 6 weeks, while the nerve recovery period varied between 1.5 and 4.0 months. The evaluation results of nerve recovery were excellent in 20 cases, good in 1 case, fair in 0 case, and poor in 0 case. None of the children had cubitus varus or cubitus valgus. Elbow joint function Flynn score results:excellent in 20 cases, good in 1 case, fair in 0 case, poor in 0 case. In the treatment of supracondylar fracture of humerus complicated with nerve injury, ultrasound provides a reference for the choice of treatment plan, reducing the probability of re-nerve injury, no radiation, good recovery of elbow joint function and other advantages, and the clinical effect is satisfactory.

Observers exhibit systematic biases when estimating the walking direction of point-light walkers (PLWs). Previous research suggests that biomechanical information plays a key role in this process, yet the underlying computational mechanisms remain poorly understood. To address this question, we developed a multivariate differential-phase model that formalizes how biokinetic asymmetries between the left and right sides of the body contribute to the bias in the estimation of biological motion directions. We first computed asymmetry indices (ASI) for key joint angles, ranges of motion, and gait parameters across different walking directions. Hierarchical clustering identified four functional modules from these ASIs. We then constructed and compared both single-factor and multi-factor differential-phase models in their ability to fit behavioral data. Results revealed that a four-factor model integrating knee and elbow joint angles, their ranges of motion, and step length, provided the best account of direction estimation biases (highest R2, lowest AIC/BIC). These findings provide a novel computational framework for understanding how bio-kinematic asymmetries contribute to directional estimation biases in biological motion, advancing our understanding of the mechanisms underlying biological motion processing.

Mongolian horses are an indigenous Chinese breed known for their endurance capacity, yet quantitative descriptions of their gait-related kinematic characteristics remain limited. This pilot exploratory study aimed to describe the kinematics of Mongolian horses during walk, slow trot, and fast trot, and to examine whether selected variables differed between race-result groups in a 12 km endurance race. Forty-six horses were classified into an excellent group and an ordinary group based on the result of a single race. Kinematic data were collected using optical motion capture and three-dimensional skeletal modelling. Separate gait-specific linear mixed-effects models were fitted, with horse identity as a random effect and group and speed as fixed effects. The results showed gait-dependent between-group differences. During walk, the excellent group had significantly greater range of motion of the tarsal, hip, and elbow joints, as well as a greater maximum forelimb retraction angle (all p < 0.001). During slow trot, the excellent group showed significantly greater stride length (p = 0.009), elbow joint range of motion (p < 0.001), minimum hindlimb forward extension angle (p = 0.033), and minimum forelimb forward extension angle (p = 0.004). During fast trot, the between-group differences were most pronounced, with significantly greater stride length (p < 0.001) and range of motion of the tarsal joint (p < 0.001), hip joint (p = 0.015), and elbow joint (p = 0.014), together with greater maximum hindlimb retraction angle (p = 0.001) and minimum forelimb forward extension angle (p = 0.026). Overall, these findings provide preliminary evidence that gait-related kinematic differences may exist between race-result groups in Mongolian horses. However, because this was an exploratory study based on a single race, the findings should be interpreted cautiously and require validation in larger and more diverse cohorts.

Purpose: The objective of this study is to compare the maximum voluntary isometric contraction (MVIC) values obtained from the biceps brachii (BB) and triceps brachii (TB) muscles at different elbow angles and to determine which angle provides optimum efficiency according to this comparison. Methods: A total of 30 healthy volunteers participated in the study. Electromyography (EMG) data were obtained at 70°, 90°, and 110° of flexion to measure root mean square (RMS) amplitude during MVIC of BB (for elbow flexion) and TB (for elbow extension) muscles. Results: For BB, EMG RMS amplitude during MVIC was significantly influenced by elbow joint angle, with the highest activation observed at 70° compared to 90° and 110°. Similarly, TB activation was angle-dependent, showing the greatest values at 70°. The BB/TB EMG RMS ratio further confirmed consistently greater activation of BB across all joint angles. Post-hoc analyses revealed that BB activation was significantly greater at 70° compared with 90° and 110°, while TB activation was higher at 70° compared with 90° and 110°, and also higher at 90° compared with 110°.Conclusion: The findings demonstrated that joint angle influences EMG amplitudes during MVIC for both BB and TB muscles. These findings highlight the importance of joint angle selection in exercise prescription and rehabilitation.

The function of the anconeus has been previously described for the muscle as a whole. No studies were found that explored the functional neuromuscular partitioning based on 3D muscle architecture and innervation patterns, which is paramount to understanding changes in pathological muscle. The purpose of this study was to investigate 3D muscle morphology and intramuscular innervation of the anconeus, quantify architectural parameters, and propose functional implications of the findings. The fiber bundles, aponeuroses, and intramuscular innervation of the anconeus (n = 8 embalmed specimens, mean age 81 ± 12 years) were serially dissected, digitized, and modeled in 3D. Muscle morphology and intramuscular innervation patterns were determined and architectural parameters computed. The 3D models and data were used to assess muscular partitioning and propose functional implications of the findings. The anconeus was found to be morphologically partitioned into three parts, proximal, distal, and deep, based on fiber bundle orientation, attachment sites, and architectural parameters. The nerve to anconeus supplied the proximal part and underlying deep part. The nerve bifurcated to supply the distal part via medial and lateral branches or superficial and deep branches. In conclusion, the proximal part could act as an abductor of the ulna, the distal part as an initial elbow extensor, and deep part as a stabilizer and tensor of the elbow joint capsule. The in-depth 3D mapping of the anconeus will enable the development of invivo ultrasound protocols to provide further insight into the invivo functions of the three parts of the anconeus.

Diagnosis and management of hemophilia A and B.

To evaluate whether operative irrigation and debridement (I&D) is necessary for the treatment of pediatric traumatic arthrotomies (TAs) secondary to gunshot wounds (GSWs) to prevent joint infections. Retrospective cohort study. US Academic Level I Trauma Center. Pediatric patients (age 0-17) with TAs secondary to GSW between 2016 and 2023 with at least 1-month follow-up were included. Arthrotomies included shoulder, elbow, wrist, hand, sacroiliac, hip, knee, ankle, or foot joints. The primary outcome was rate of joint infection between those who received acute operative I&D versus those who received nonoperative management. A subanalysis was completed only comparing "major joints." Within the cohorts, length of antibiotic treatment was compared. Fifty seven cases of ballistic TA (50 subjects, 82% male, mean age 14.6 years) were included. In total, 31 of 57 joints (54.4%) underwent formal operative I&D with or without fixation, while 26 joints (45.6%) did not. In the operative I&D cohort, 85% were male with a mean age 14.8 years versus 79% male with mean age of 14.3 years in the nonoperative group. Mean follow-up duration was 10.8 months (range 1-56 months) for both cohorts. No joint infections were documented between either group, regardless of treatment ( P = 1.0). In total, 38 TAs were major joints: 23 of 38 (60.5%) received I&D, while 15 of 38 (39.5%) did not. All joints received at least 1 dose of intravenous (IV) antibiotics. Among the operative group, 54.8% of joints received ≤72 hours of IV antibiotics (45.2% received >72 hours), compared with 46.2% of joints in the nonoperative group (53.8% received >72 hours). Formal operative I&D was not found to be necessary to prevent joint infection after TA secondary to GSW. Prolonged antibiotic use did not affect rates of infection. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Anatomical explanation of the screw motion of the elbow joint.

As humans and other animals age, passive and active muscle properties change markedly, with reduced peak tension, peak strain rate, activation and deactivation rate, and increased parallel stiffness. It is thought that these alterations modify locomotor performance, but establishing causal links is difficult when many parameters vary at once. We developed a simplified model of an elbow joint with two antagonistic Hill-type muscles, and varied the associated muscle parameters combinatorially over a large range. For a given parameter combination, we found optimal joint movements that minimized cumulative squared error to a target while starting and ending at rest. Emergent behaviour from the optimisations compared well to ballistic point-to-point arm movements in humans. Age-associated reductions of maximum isometric force, maximum strain rate and activation rate all had detrimental effects on performance, independent of other parameters. In contrast, deactivation time and passive parallel stiffness had no effect on performance on their own, but pronounced interactive effects with each other. Increasing stiffness reduced joint movement time at fast deactivation rates, but increased movement time at slow deactivation rates. This occurs because antagonist muscles resist the passive tension at rest, but are stretched eccentrically by the agonist, amplifying their active resistive force. Fast-deactivating muscles can avoid this resistive effect, allowing the passive stiffness to amplify accelerating force and enhance performance. In all cases, coactivation emerged as optimal during and after the braking period, and during the acceleration phase when stiffness increased. As deactivation time increased, so too did coactivation levels- but coactivation was not generally associated with a reduction in performance. Our simulations offer evidence that age-related changes in muscle strength, activation time and maximum contraction velocity can reduce ballistic performance in a goal-directed task, but the effects of increased muscle stiffness and deactivation time depend on their relative values.