High-resolution ultrasound approach to quadrangular joint in carpal boss: Everything musculoskeletal sonographer should know.

At the quadrangular joint (QAJ) of the carpus, a rare bony protuberance called carpal boss (CB) may occur. This bone abnormality may be due to osteophytes development or os styloideum. Symptomatic patients may complain pain, swelling, and restrictions in hand motion. These symptoms result from joint degenerative-inflammatory changes, development of ganglion cyst/bursitis, or tendons pathology. Correct diagnosis and appropriate management can be achieved through high-resolution ultrasonography (HR-US). The purpose of this review is to define the pathology spectrum around and within the QAJ in CB. The role of HR-US is highlighted and the standard technique for the QAJ assessment is described.

Can we encourage the endoscopic treatment for external snapping hip (ESH)? A systematic review of current concepts.

BACKGROUND: Snapping hip syndrome (SHS) is characterized by snapping sensation and pain and affects up to 10% of the general population. External snapping hip syndrome (ESHS), the most common form, is often due to repetitive movements in sports or anatomical predispositions. Conservative treatment includes physiotherapy and corticosteroid injections, while surgery is considered if conservative measures fail. Open surgical techniques carry several risks, while modern arthroscopic techniques offer less invasive options, such as endoscopic iliotibial band release (ITB) and gluteus maximus tenotomy. MATERIALS AND METHODS: A systematic review was conducted adhering to the PRISMA guidelines. Relevant studies were searched in four databases: Pubmed, Scopus, Embase, and Medline. The selected articles were evaluated according to the criteria of levels of evidence. The Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) was used to analyze the retrospective studies. This paper was registered in the International Prospective Registry of Systematic Reviews (PROSPERO). RESULTS: Out of 9 included studies, 403 patients with 689 hips underwent endoscopic treatment. ITB release and his variations were the main surgical techniques. Gluteus maximus tenotomy was also used in some studies. Postoperative rehabilitation protocols varied. Patients generally experienced significant improvements in symptoms and functional outcomes, with low rates of recurrence (1.02%) and revision (0.15%). Complications were minimal. CONCLUSIONS: Endoscopic treatment of ESH shows favorable results, improving functional outcomes and returning patients to pre-injury activity levels. Long-term efficacy and costeffectiveness need to be evaluated, emphasizing the importance of large-scale prospective randomized trials to clarify surgery's benefits in refractory ESH cases.

Invertebrate sounds from photic to mesophotic coral reefs reveal vertical stratification and diel diversity.

Although mesophotic coral ecosystems account for approximately 80% of coral reefs, they remain largely unexplored due to their challenging accessibility. The acoustic richness within reefs has led scientists to consider passive acoustic monitoring as a reliable method for studying both altiphotic and mesophotic coral reefs. We investigated the relationship between benthic invertebrate sounds (1.5-22.5 kHz), depth, and benthic cover composition, key ecological factors that determine differences between altiphotic and mesophotic reefs. Diel patterns of snaps and peak frequencies were also explored at different depths to assess variations in biorhythms. Acoustic recorders were deployed at 20 m, 60 m, and 120 m depths across six islands in French Polynesia. The results indicated that depth is the primary driver of differences in broadband transient sound (BTS) soundscapes, with sound intensity decreasing as depth increases. At 20-60 m, sounds were louder at night. At 120 m depth, benthic activity rhythms exhibited low or highly variable levels of diel variation, likely a consequence of reduced solar irradiation. On three islands, a peculiar peak in the number of BTS was observed every day between 7 and 9 PM at 120 m, suggesting the presence of cyclic activities of a specific species. Our results support the existence of different invertebrate communities or distinct behaviors, particularly in deep mesophotic reefs. Overall, this study adds to the growing evidence supporting the use of passive acoustic monitoring to describe and understand ecological patterns in mesophotic reefs.

Machine-learning based detection of marine mammal vocalizations in snapping-shrimp dominated ambient noise.

Passive acoustics is an effective method for monitoring marine mammals, facilitating both detection and population estimation. In warm tropical waters, this technique encounters challenges due to the high persistent level of ambient impulsive noise originating from the snapping shrimp present throughout this region. This study presents the development and application of a neural-network based detector for marine-mammal vocalizations in long term acoustic data recorded by us at ten locations in Singapore waters. The detector's performance is observed to be impeded by the high shrimp noise activity. To counteract this, we investigate several techniques to improve detection capabilities in shrimp noise including the use of simple nonlinear denoisers and a machine-learning based denoiser. These are shown to enhance the detection performance significantly. Finally, we discuss some of the vocalizations detected over three years of our acoustic recorder deployments using the robust detectors developed.

Assessment of function and muscle strength after endoscopic iliopsoas tenotomy to treat iliopsoas impingement after total hip arthroplasty.

PURPOSE: The objective of this study was to evaluate the functional outcome during follow-up (FU) after endoscopic tenotomy for iliopsoas (IP)-cup impingement and to quantitatively analyze the hip flexion strength. METHODS: This was a monocentric, retrospective cohort study of a single surgeon series. Functional assessment was based on the modified Harris score, the Oxford score and the visual analog scale score. Strength was measured with a handheld dynamometer in the sitting and lying position. RESULTS: Thirty-six IP tenotomies for cup impingement were performed between May 2013 and November 2021. Seven (19%) patients were lost to FU. At the time of tenotomy, the mean (standard deviation) age was 62,6 (12,2) and BMI was 26,5 (4,1). The mean FU time after tenotomy to the last FU was 3,6 (0,8) years. All three outcome scores improved from preoperatively to six months postoperatively (p < 0.001). There were no significant change from six months to last FU. The minimal clinically important difference (MCID) of the modified Harris score was set at 25. 20 (69%) patients had values that exceeded the threshold at one month and six months and neutral 19 (65.5%) had values that exceeded the threshold at the last FU. The limp symmetry index concerning hip flexion strength was 63% at 90° and 40% at 30° at the last FU. CONCLUSION: Most patients significantly improved their outcome scores after endoscopic iliopsoas tenotomy, with results remaining consistently stable over time. Despite a significant loss in hip flexion strength, the majority of patients did not report any impairment of their quality of life. STUDY DESIGN: Level III, Retrospective cohort study.

Tailoring Stress-Strain Curves of Flexible Snapping Mechanical Metamaterial for On-Demand Mechanical Responses via Data-Driven Inverse Design.

By incorporating soft materials into the architecture, flexible mechanical metamaterials enable promising applications, e.g., energy modulation, and shape morphing, with a well-controllable mechanical response, but suffer from spatial and temporal programmability towards higher-level mechanical intelligence. One feasible solution is to introduce snapping structures and then tune their responses by accurately tailoring the stress-strain curves. However, owing to the strongly coupled nonlinearity of structural deformation and material constitutive model, it is difficult to deduce their stress-strain curves using conventional ways. Here, a machine learning pipeline is trained with the finite element analysis data that considers those strongly coupled nonlinearities to accurately tailor the stress-strain curves of snapping metamaterialfor on-demand mechanical response with an accuracy of 97.41%, conforming well to experiment. Utilizing the established approach, the energy absorption efficiency of the snapping-metamaterial-based device can be tuned within the accessible range to realize different rebound heights of a falling ball, and soft actuators can be spatially and temporally programmed to achieve synchronous and sequential actuation with a single energy input. Purely relying on structure designs, the accurately tailored metamaterials increase the devices' tunability/programmability. Such an approach can potentially extend to similar nonlinear scenarios towards predictable or intelligent mechanical responses.

Damage to tropical forests caused by cyclones is driven by wind speed but mediated by topographical exposure and tree characteristics.

Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world.

Reversible Snapping of Constrained Anisotropic Hydrogels Upon Light Stimulations.

Creatures, such as Venus flytrap and hummingbirds, capable of rapid predation through snap-through transition, provide paradigms for the design of soft actuators and robots with fast actions. However, these artificial "snappers" usually need contact stimulations to trigger the flipping. Reported here is a constrained anisotropic poly(N-isopropylacrylamide) hydrogel showing fast snapping upon light stimulation. This hydrogel is prepared by flow-induced orientation of nanosheets (NSs) within a rectangular tube. The precursor containing gold nanoparticles is immediately exposed to UV light for photopolymerization to fix the ordered structure of NSs. Two ends of the slender gel are clamped to form a buckle with bistability nature, which snaps to the other side upon laser irradiation. Systematic experiments are conducted to investigate the influences of power intensity and irradiation angle of the laser, as well as thickness and buckle height of the gel, on the snapping behaviors. The fast snapping is further used to kick a plastic bead and control the switch state. Furthermore, synergetic or oscillated snapping of the gel with two buckles of opposite directions is realized by inclined irradiation of a laser or horizontal irradiation with two lasers, respectively. Such light-steered snapping of hydrogels should merit designing soft robots, energy harvests, etc.

Minimum 5-Year Clinical and Return-to-Sport Outcomes After Primary Arthroscopic Scapulothoracic Bursectomy and Partial Scapulectomy for Snapping Scapula Syndrome.

BACKGROUND: Snapping scapula syndrome (SSS) is a rare condition that is oftentimes debilitating. For patients whose symptoms are resistant to nonoperative treatment, arthroscopic surgery may offer relief. Because of the rarity of SSS, reports of clinical outcomes after arthroscopic SSS surgery are primarily limited to small case series and short-term follow-up studies. PURPOSE: To report minimum 5-year clinical and sport-specific outcomes after arthroscopic bursectomy and partial scapulectomy for SSS and to identify demographic and clinical factors at baseline associated with clinical outcomes at minimum 5-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent arthroscopic bursectomy and partial scapulectomy for SSS between October 2005 and February 2016 with a minimum of 5 years of postoperative follow-up were enrolled in this single-center study. Clinical outcome scores, including the 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons (ASES) Shoulder Score, shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) score for pain, were collected at a minimum 5-year follow-up. Additionally, it was determined which patients reached the minimal clinically important difference. Bivariate analysis was used to determine whether baseline demographic and clinical factors had any association with the outcome scores. RESULTS: Of 81 patients eligible for inclusion in the study, follow-up was obtained for 66 patients (age 33.6 ± 13.3 years; 31 female). At a mean follow-up of 8.9 ± 2.5 years (range, 5.0-15.4 years), all of the outcome scores significantly improved compared with baseline. These included the ASES (from 56.7 ± 14.5 at baseline to 87.2 ± 13.9 at follow-up; P < .001), QuickDASH (from 38.7 ± 17.6 to 13.1 ± 14.6; P < .001), SANE (from 52.4 ± 21.2 to 82.7 ± 19.9; P < .001), SF-12 Physical Component Summary (from 39.7 ± 8.3 to 50.3 ± 8.2; P < .001), SF-12 Mental Component Summary (from 48.2 ± 11.7 to 52.0 ± 9.0; P = 0.014) and VAS pain (from 5.2 ± 2.1 to 1.4 ± 2.0; P < .001). The minimal clinically important difference in the ASES score was reached by 77.6% of the patients. Median postoperative satisfaction was 8 out of 10. It was found that 90.5% of the patients returned to sport, with 73.8% of the patients able to return to their preinjury level. At the time of final follow-up, 8 (12.1%) patients had undergone revision surgery for recurrent SSS symptoms. Older age at surgery (P = .044), lower preoperative SF-12 Mental Component Summary score (P = .008), lower preoperative ASES score (P = .019), and increased preoperative VAS pain score (P = .016) were significantly associated with not achieving a Patient Acceptable Symptom State on the ASES score. CONCLUSION: Patients undergoing arthroscopic bursectomy and partial scapulectomy for SSS experienced clinically significant improvements in functional scores, pain, and quality of life, which were sustained at a minimum of 5 years and a mean follow-up of 8.9 years postoperatively. Higher patient age, inferior mental health status, increased shoulder pain, and lower ASES scores at baseline were significantly associated with worse postoperative outcomes.

Clinical Outcomes Following Incomplete Arthroscopic Iliotibial Band Release for External Snapping Hip Syndrome: An Observational Study.

OBJECTIVES: Arthroscopic treatment is indicated for external snapping hip (ESH) syndrome in patients refractory to conservative treatment, but snapping does not disappear completely in some case. No previous studies have described the clinical course of ESH syndrome in patients who presented with persistent snapping after an arthroscopic procedure. We demonstrated the clinical outcomes following an incomplete arthroscopic iliotibial band (ITB) release for ESH syndrome. METHODS: This retrospective observational study was performed at two teaching hospitals between October 2015 and December 2021. We reviewed the data of 33 patients (34 hips) aged ≥18 years, diagnosed with ESH syndrome, who were treated with arthroscopic ITB release. Patients who presented with persistent snapping despite sufficient arthroscopic ITB release following systematic order were defined as having an incomplete release. We collected the data for recurrent symptomatic snapping hip as the primary outcome after a minimum 2-year follow-up. The visual analogue scale (VAS) and modified Harris hip (mHHS) scores were measured as secondary outcome. RESULTS: "Incomplete release" was identified in three of the 34 hips (8.9%). Cases of recurrent symptomatic snapping or conversion to open surgery were not observed. The symptoms of residual snapping spontaneously disappeared in all cases following routine postoperative rehabilitation within a 3-month follow-up period. The VAS (4 ± 1) and mHHS (17 ± 6) scores of all the patients improved. CONCLUSION: When refractory ESH syndrome is identified during arthroscopic surgery, appropriate ITB release and removal of the major lesion causing snapping are expected to lead to resolution of residual symptoms without conversion to open surgery.

Preoperative patient factors that predict achieving the minimal clinically important difference following arthroscopic treatment of snapping scapula syndrome.

BACKGROUND: The aim of this study was to define the minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) after arthroscopic treatment of snapping scapula syndrome (SSS) using a distribution-based method, and to identify demographic, clinical, and intraoperative factors significantly associated with the achievement of MCID. It was hypothesized that subjective satisfaction scores after the procedure would be strongly associated with the achievement of MCID thresholds for the PROs and that pain, preoperative response to injection, and a scapulectomy in addition to bursal resection would be predictive of clinically relevant improvement. METHODS: Patients who underwent arthroscopic treatment of SSS between October 2005 and September 2020 with a minimum of 2-year short-term postoperative follow-up were enrolled in this retrospective single-center study. The MCID was calculated using a distribution-based approach for the following PROs: 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain "today" and "at worst." The association between achievement of the MCID and postoperative subjective satisfaction was investigated, and factors associated with achievement of MCID were determined using bivariate analysis. RESULTS: Of a total of 190 patients assessed for eligibility, 77 patients (38.1 ± 14.3 years; 36 females) were included. Within the study population, statistically significant improvements in postoperative SF-12 physical component summary (PCS) (P < .001) and mental component summary (MCS) (P < 0.034), ASES (P < .001), QuickDASH (P < .001), SANE (P < .001), and VAS pain (P < .001) scores were observed at the minimum 2-year follow-up. The calculated MCID threshold values based on the study population were 5.0 for SF-12 PCS, 5.8 for SF-12 MCS, 11.3 for ASES, -10.5 for QuickDASH, 14.7 for SANE, 1.5 for VAS pain, and 1.7 for VAS pain at worst. Reaching the MCID was strongly associated with postoperative satisfaction (rated on a scale of 1-10). Across the PROs, younger age, favorable preoperative response to injection, partial scapuloplasty or scapulectomy, no prior surgery, and pain and function at baseline were significantly associated with attaining MCID. CONCLUSIONS: Patients who underwent arthroscopic treatment for SSS experienced clinically significant improvements in functional scores, pain, and quality of life. This study demonstrated predictive roles for certain patient-specific factors and diagnostic variables for achieving MCID in PROs, which may help surgeons preoperatively assess the probability of success and manage patient expectations.

Snapping Wrist From Bowstringing of the Digital Flexors After Carpal Tunnel Release: A Case Report.

Symptomatic bowstringing of digital flexor tendons is a rare complication of carpal tunnel release (CTR). Two weeks after open CTR, a 47-year-old man with severe carpal tunnel syndrome had relief of his preoperative median paresthesia but complained of new-onset painful snapping of the wrist and transient ulnar paresthesia occurring with wrist dorsiflexion and concomitant digital flexion. Physical examination localized the audible snapping to the hook of hamate (HOH) where manual pressure eliminated the wrist motion-induced snapping and the associated ulnar paresthesia. Wrist radiographs showed stage III scapholunate advanced collapse (SLAC) with marked palmar subluxation of the lunate. Wrist magnetic resonance imaging revealed palmar and ulnar subluxation of the digital flexors over the HOH due to the mass effect of the palmarly displaced lunate and the chronic carpal malalignment. The snapping wrist and accompanying ulnar paresthesia resolved after HOH excision, and no additional treatment for the asymptomatic SLAC wrist deformity was required. Satisfactory clinical outcome was observed at 5-year follow-up.

Efficacy of Minimally Invasive Ulnar Superficialis Slip Resection for Unfavourable Results after Trigger Finger Release.

Background: This study aimed to evaluate the efficacy of ulnar superficial slip resection (USSR) for improving hand function after unfavourable results after triggering finger release using a minimally invasive approach. Methods: We evaluated 17 consecutive fingers of 16 patients who complained of unfavourable outcomes after primary trigger finger release. The chief complaints of the two index and 15 middle fingers were proximal interphalangeal (PIP) joint pain during movement, flexion contracture of the PIP joint and snapping at the A2 pulley in eight, seven and two fingers, respectively. The joint arc of the active range of motion and extension loss of the PIP joint, grip strength, visual analogue score (VAS) of PIP joint pain and Quick Disability of the Arm, Shoulder and Hand were evaluated before and after surgery. Results: Thirteen fingers could release joint contracture and snapping by the USSR procedure. However, four fingers of three patients required total flexor digitorum superficialis resection to resolve the unsatisfactory conditions of the intraoperative decision. The joint arc of active range of motion and extension loss of the PIP joint, grip strength and VAS score significantly improved (mean of 16.1 months follow-up). Finally, 15 patients (88.2%) were satisfied with the symptom relief outcomes. Conclusions: USSR is an effective and satisfactory procedure for unfavourable conditions after trigger finger release, including PIP joint pain, joint contracture and snapping at the A2 pulley. Level of Evidence: Level IV (Therapeutic).

Painful snapping of the middle finger caused by hyperplasia of the ulnar lateral band: A case report.

Snapping of fingers can be caused by pathologies such as stenosing flexor tenosynovitis. However, snapping symptoms in the metacarpophalangeal (MP) joint caused by hypertension and hyperplasia of the lateral band are rare. We present a 26-year-old female with symptoms of painful snapping of the middle finger. When the finger was actively flexed from the hyperextension of the MP joint, the ulnar lateral band was prominent, and a snapping phenomenon occurred. The cause of the snapping finger was considered to be tightness of the ulnar lateral band, and surgery was planned. Intraoperatively, the ulnar lateral band was tense and hyperplastic. The snapping phenomenon disappeared immediately after the resection of the lateral band. It is important to consider this condition as one of the differential diagnoses of snapping finger when the patient complains of an atypical snapping phenomenon.

Multimodality imaging review of ulnar nerve pathologies.

The ulnar nerve is the second most commonly entrapped nerve after the median nerve. Although clinical evaluation and electrodiagnostic studies remain widely used for the evaluation of ulnar neuropathy, advancements in imaging have led to increased utilization of these newer / better imaging techniques in the overall management of ulnar neuropathy. Specifically, high-resolution ultrasonography of peripheral nerves as well as MRI has become quite useful in evaluating the ulnar nerve in order to better guide treatment. The caliber and fascicular pattern identified in the normal ulnar nerves are important distinguishing features from ulnar nerve pathology. The cubital tunnel within the elbow and Guyon's canal within the wrist are important sites to evaluate with respect to ulnar nerve compression. Both acute and chronic conditions resulting in deformity, trauma as well as inflammatory conditions may predispose certain patients to ulnar neuropathy. Granulomatous diseases as well as both neurogenic and non-neurogenic tumors can also potentially result in ulnar neuropathy. Tumors around the ulnar nerve can also lead to mass effect on the nerve, particularly in tight spaces like the aforementioned canals. Although high-resolution ultrasonography is a useful modality initially, particularly as it can be helpful for dynamic evaluation, MRI remains most reliable due to its higher resolution. Newer imaging techniques like sonoelastography and microneurography, as well as nerve-specific contrast agents, are currently being investigated for their usefulness and are not routinely being used currently.

Gluteal Complex is important in External Snapping Hip: intraoperative identification of syndrome origin and endoscopic stepwise release-a case series.

PURPOSE: External snapping hip syndrome (ESHS) was historically attributed to isolated iliotibial band (ITB) contracture. However, the gluteus maximus complex (GMC) may also be involved. This study aimed to intraoperatively identify the ESHS origin and assess the outcomes of endoscopic treatment based on the identified aetiological type. METHODS: From 2008-2014, 30 consecutive patients (34 hips) with symptomatic ESHS cases refractory to conservative treatment underwent endoscopic stepwise "fan-like" release, gradually addressing all known reasons of ESHS: from the isolated ITB, through the fascial part of the GMC until a partial release of gluteus maximus femoral attachment occurred. Snapping was assessed intra-operatively after each surgical step and prospectively recorded. Functional outcomes were assessed via the MAHORN Hip Outcome Tool (MHOT-14). RESULTS: Twenty seven patients (31 hips) were available to follow-up at 24-56 months. In all cases, complete snapping resolution was achieved intra-operatively: in seven cases (22.6%) after isolated ITB release, in 22 cases (70.9%), after release of ITB + fascial part of the GMC, and in two cases (6.5%) after ITB + fascial GMC release + partial release of GM femoral insertion. At follow-up, there were no snapping recurrences and MHOT-14 score significantly increased from a pre-operative average of 46 to 93(p<0.001). CONCLUSION: Intraoperative identification and gradual addressing of all known causes of ESHS allows for maximum preservation of surrounding tissue during surgery while precisely targeting the directly involved structures. Endoscopic stepwise "fan-like" release of the ITB and GMC is an effective, tailor-made treatment option for ESHS regardless of the snapping origin in the patients with possibility to manually reproduce the snapping.

Snapping for 4D-Printed Insect-Scale Metal-Jumper.

The replication of jumping motions observed in small organisms poses a significant challenge due to size-related effects. Shape memory alloys (SMAs) exhibit a superior work-to-weight ratio, making them suitable for jumping actuators. However, the SMAs advantages are hindered by the limitations imposed by their single actuator configuration and slow response speed. This study proposes a novel design approach for an insect-scale shape memory alloy jumper (net-shell) using 4D printing technology and the bistable power amplification mechanism. The energy variations of the SMA net-shell under different states and loads are qualitatively elucidated through a spring-mass model. To optimize the performance of the SMA net-shell, a non-contact photo-driven technique is employed to induce its shape transition. Experimental investigations explore the deformation response, energy release of the net-shell, and the relationship between the light power density. The results demonstrate that the SMA net-shell exhibits remarkable jumping capabilities, achieving a jump height of 60 body lengths and takeoff speeds of up to 300 body lengths per second. Furthermore, two illustrative cases highlight the potential of net-shells for applications in unstructured terrains. This research contributes to miniaturized jumping mechanisms by providing a new design approach integrating smart materials and advanced structures.

Bilateral snapping triceps syndrome: A case report.

BACKGROUND: Snapping triceps syndrome (STS) is a rare disease, while occurrence of bilateral STS is extremely rare. It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature. However, to the best of our knowledge, there has been no report of bilateral STS in young active patient. CASE SUMMARY: A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups. On physical examination, two distinct snaps that were both palpable and audible were detected on additional clinical examination. Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion. Finally, he was diagnosed as dislocation of the ulnar nerve and STS. Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed. The patient's pain and snapping symptoms were resolved immediately after surgery. Three months later, the patient was completely asymptomatic and returned to normal activity. CONCLUSION: STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint, particularly when dislocation of the ulnar nerve is detected. Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.

Sensor Fusion-Based Anthropomorphic Control of a Robotic Arm.

The main goal of this research is to develop a highly advanced anthropomorphic control system utilizing multiple sensor technologies to achieve precise control of a robotic arm. Combining Kinect and IMU sensors, together with a data glove, we aim to create a multimodal sensor system for capturing rich information of human upper body movements. Specifically, the four angles of upper limb joints are collected using the Kinect sensor and IMU sensor. In order to improve the accuracy and stability of motion tracking, we use the Kalman filter method to fuse the Kinect and IMU data. In addition, we introduce data glove technology to collect the angle information of the wrist and fingers in seven different directions. The integration and fusion of multiple sensors provides us with full control over the robotic arm, giving it flexibility with 11 degrees of freedom. We successfully achieved a variety of anthropomorphic movements, including shoulder flexion, abduction, rotation, elbow flexion, and fine movements of the wrist and fingers. Most importantly, our experimental results demonstrate that the anthropomorphic control system we developed is highly accurate, real-time, and operable. In summary, the contribution of this study lies in the creation of a multimodal sensor system capable of capturing and precisely controlling human upper limb movements, which provides a solid foundation for the future development of anthropomorphic control technologies. This technology has a wide range of application prospects and can be used for rehabilitation in the medical field, robot collaboration in industrial automation, and immersive experience in virtual reality environments.

Biceps femoris accessory tendon tenodesis: A case report.

Key Clinical Message: We present a case of lateral knee pain from snapping of an accessory tendinous insertion of the biceps femoris. After failure of conservative treatment options, tenodesis of the accessory band to the direct arm insertion at the posterolateral edge of the fibular head effectively resolved symptoms. Abstract: There are several distinct causes of lateral knee pain including IT band syndrome, meniscus tears, or other soft tissue pathologies; however, a few case reports have shown the biceps femoris as a cause of lateral knee pain and snapping. Conservative treatment is of modest benefit to the patient in these scenarios, and an MRI is not always able to identify the accessory band, as in our case. Intraoperatively, we discovered an accessory band of the biceps femoris attaching to the anterolateral tibia, causing pain and snapping during knee flexion as the band passed over the fibular head. There have been various surgical attempts to address this pathology; however, we report a successful outcome after tenodesis of the accessory band to the direct insertion at the posterolateral fibular head.