Elbow Motion Research Articles

A cable-driven elbow exoskeleton with variable stiffness actuator for upper limb rehabilitation

Abstract Elbow, with complex physiological structure, plays an important role in upper limb motion which can be assisted with exoskeleton in rehabilitation. However, the stiffness of elbow changes while training which decline the comfort and effect of rehabilitation. Moreover, the rotation axis of elbow is changing which will cause secondary injuries. In this paper, we design an elbow exoskeleton with a variable stiffness actuator and a deviation compensation unit to assist elbow rehabilitation. Firstly, we design a variable stiffness actuator by symmetric actuation principle to adapt the change of elbow stiffness. The parameters of the variable stiffness actuator are optimized by motion simulation. Next, we design a deviation compensation unit to follow the rotation axis deviation outside the horizontal plane. The compensation area is simulated to cover the deviation. Finally, simulation and experiments are carried out to show the performance of our elbow exoskeleton. The workspace can meet the need of daily elbow motion while the variable stiffness actuator can adjust the exoskeleton stiffness as expectation.

Timing of Surgery for Elbow Fractures (OTA 13 A-C and 21 A-C) and Patient Outcomes.

To determine if there is a correlation between time to surgery (TTS) and outcomes following repair of elbow fractures. Design: Retrospective comparative study. A single, urban hospital system. Patients from March 2011 to September 2022 who sustained an isolated fracture about the elbow joint (AO/OTA 13-A, B, and C and 21-A, B, and C), underwent surgical repair, and had at least 6 months of post-operative follow up identified from an Institutional Review Board-approved database. Time to surgery, in days, was recorded. Radiographic and clinical follow up was obtained at all visits and a Mayo Elbow Performance Index (MEPI) was calculated based on the latest follow up. Complications recorded: elbow contracture, infection, early hardware failure, reoperation, and fracture nonunion. Multivariable regression and Spearman correlation analysis were used to determine any significant outcome differences based on time to surgery. 351 patients included with a mean age of 54.8 (range: 18 - 86) years with 217 females (61.8%) and 134 males (38.2%). Eighty-two patients (23.4%) developed at least one complication while 269 patients (76.6%) did not. As a continuous variable, TTS was not correlated with arc of motion at any follow up visit nor with the latest recorded MEPI score (p > 0.05). Mean TTS for patients who did and did not experience a complication was 6 (range: 0-24) and 10 (range: 0-38) days, respectively, and this was not significantly different (p = 0.217). Complication rate and any of the individual complications were not associated with TTS following a multivariable analysis controlling for age, sex, injury mechanism, open fracture, Charlson Comorbidity Index, and AO/OTA classification (p > 0.05 for all). Timing of surgery following OTA 13 A-C and 21 A-C elbow fractures was not associated with differences in post-operative complications or range of elbow motion. Level III.

Management of extra-articular fracture of the distal humerus with the upside-down use of PHILOS plates in front of the humerus: a retrospective study of 20 patients after 28.3 months

BackgroundExtra-articular distal humerus locking plates (EADHPs) have been widely employed for the treatment of extra-articular fractures of the distal humerus, but interference with the radial nerve and poor fastening of distal fracture fragments by screws remain. The aim of this study is to evaluate the clinical and imaging effects of the anterolateral approach in the treatment of extra-articular fractures of the distal humerus with the upside-down use of proximal humerus internal locking system (PHILOS) plates in front of the humerus.MethodA retrospective analysis (10/2018–10/2022) was conducted on the clinical data of patients with extra-articular fractures of the distal humerus treated with the upside-down use of the PHILOS via the anterolateral approach. The fracture union time, range of motion of the elbow joint, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH) score, Visual Analogue Scale (VAS) score for pain and incidence of complications were analysed at the final follow-up.ResultsA total of 20 patients (11 males, 9 females) with a mean age of 40.3 ± 17.0 years (16–87 years) and a follow-up of 28.3 ± 10.8 months (15–53 months) were evaluated. The average number of screws in the distal humeral fragment was 5.7 ± 0.6. The average fracture union time was 23.3 ± 3.3 weeks. The mean longest and shortest cortical lengths from the coronoid fossa were 87.3 ± 13.4 mm and 47.9 ± 9.4 mm, respectively. At the final follow-up, the average range of elbow motion was − 3.3 ± 2.6° of extension and 135.1 ± 3.1° of flexion. The mean MEPS score was 97.8 ± 6.0. The mean DASH score was 1.25 ± 3.6 (range, 0–15.9), and the mean VAS score was 0.1 ± 0.4 (range, 0–2). None of the patients developed serious complications that required reoperation.ConclusionsThe upside-down use of PHILOS plates in front of the humerus has good results in the treatment of extra-articular fractures of the distal humerus, so it is an alternative for fixing distal humerus extra-articular diaphyseal fractures when EADHPs are not suitable or preferred, especially for smaller distal fracture fragments, and reducing interference with the radial nerve.

Treatment and Early Outcomes of Capitellar Osteochondritis Dissecans.

Treatment for osteochondritis dissecans (OCD) of the humeral capitellum has been predominantly guided by fragment stability and articular cartilage integrity. Nonoperative management is recommended for stable lesions, whereas surgical intervention is indicated for unstable lesions and those that fail nonoperative care. Several surgical options may be considered, although limited information is available regarding indications for specific surgical techniques and comparative postoperative results. To assess surgical outcomes of patients with capitellar OCD treated according to a decision-making approach focused on subchondral bone involvement. Cohort study; Level of evidence, 3. Patients diagnosed with capitellar OCD at a tertiary academic center were enrolled in a prospective longitudinal cohort study. Patient information was collected at the time of enrollment, and OCD lesions were classified according to the Nelson grade. Clinical and radiologic data were collected both pre- and postoperatively for those undergoing surgical treatment. Surgical procedures were performed based on an evolving treatment framework that included considerations specifically for lesion containment and depth of subchondral bone disease. Timmerman scores were obtained to assess patient functional outcomes. A total of 154 patients were prospectively enrolled, 19 of whom had bilateral disease. The mean age at presentation was 13.7 years; 39% were gymnasts and 28.5% were primary baseball or softball athletes. Surgery was performed on 145 elbows, including 43 drilling/microfracture procedures, 21 internal fixations, and 63 autologous osteochondral grafting (OG) procedures. Clinically, there were significant improvements in pain, elbow motion, and mechanical symptoms. Timmerman scores significantly improved after each type of surgical procedure. A total of 76% of patients returned to their primary sport. When stratified by the Nelson grade, patients with OG had lower revision surgery rates than those treated with drilling/microfracture and fixation. Furthermore, for Nelson grade 2 lesions, patients treated with OG had significantly better postoperative elbow motion and higher Timmerman scores compared with those treated with other procedures. Using a treatment framework incorporating lesion containment and depth of subchondral bone disease, surgery for capitellar OCD provides clinical, radiologic, and functional improvements. Patients treated with OG may have lower revision rates and better functional outcomes compared with those treated with other surgical techniques, with OG warranting consideration even for lower-grade OCD lesions.

Surgical Treatment for Chronic Anterior Dislocation of the Radial Head.

Background: Surgical correction of chronic anterior dislocation of the radial head in paediatric patients is challenging, and they may experience re-dislocation or subluxation even after corrective surgery. We have been performing a radial shortening osteotomy combined with reconstruction of the annular and lateral collateral ligaments, and a corrective osteotomy of the ulna. The aim of this article is to describe our technique and outcomes at mid-term follow-up. Methods: This retrospective review included 10 paediatric patients with chronic anterior dislocation of the radial head that were surgically treated at our unit from January 2016 to July 2022. The dislocations were congenital in two patients, resulted from neglected Monteggia fractures in seven patients, and was idiopathic in one patient. The average age at surgery was 8.3 years. All patients underwent radial shortening osteotomy combined with reconstruction of the annular and lateral collateral ligaments, and a corrective osteotomy of the ulna. Outcomes with regards to period of follow-up, complications, arc of motion and the Kim elbow performance score were assessed. Results: The reduction of the radial head was maintained at the final follow-up (mean: 55 months). No acute or chronic complications occurred. The mean arc of flexion-extension improved from 124° to 140° while the arc of prono-supination decreased from 124° to 113°. The Kim elbow performance score was excellent in eight patients, fair in one and poor in one. Conclusions: A combination of radial shortening osteotomy, reconstruction of the annular and lateral collateral ligaments and corrective osteotomy of the ulna was able to maintain a stable reduction of the radial head with satisfactory elbow motion in the mid-term in paediatric patients with chronic anterior dislocation of the radial head regardless of the underlying cause. Level of Evidence: Level IV (Therapeutic).

Role of joint interactions in upper limb joint movements: a disability simulation study using wearable inertial sensors for 3D motion capture

BackgroundRestriction of movement at a joint due to disease or dysfunction can alter the range of motion (ROM) at other joints due to joint interactions. In this paper, we quantify the extent to which joint restrictions impact upper limb joint movements by conducting a disability simulation study that used wearable inertial sensors for three-dimensional (3D) motion capture.MethodsWe employed the Wearable Inertial Sensors for Exergames (WISE) system for assessing the ROM at the shoulder (flexion–extension, abduction–adduction, and internal–external rotation), elbow (flexion–extension), and forearm (pronation-supination). We recruited 20 healthy individuals to first perform instructed shoulder, elbow, and forearm movements without any external restrictions, and then perform the same movements with restriction braces placed to limit movement at the shoulder, elbow, and forearm, separately, to simulate disability. To quantify the extent to which a restriction at a non-instructed joint affected movement at an instructed joint, we computed average percentage reduction in ROM in the restricted versus unrestricted conditions. Moreover, we performed analysis of variance and post hoc Tukey tests (q statistic) to determine the statistical significance (p < 0.05 denoted using *) of the differences in ROM of an instructed joint in the unrestricted versus restricted conditions.ResultsRestricting movement at the shoulder led to a large reduction in the average ROM for elbow flexion–extension (21.93%, q = 9.34*) and restricting elbow movement significantly reduced the average ROM for shoulder flexion–extension (17.77%, q = 8.05*), shoulder abduction–adduction (19.80%, q = 7.60*), and forearm pronation-supination (14.04%, q = 4.96*). Finally, restricting the forearm significantly reduced the average ROM for shoulder internal–external rotation (16.71%, q = 3.81*) and elbow flexion–extension (10.01%, q = 4.27*).ConclusionsJoint interactions across non-instructed joints can reduce the ROM of instructed movements. Assessment of ROM in the real-world using 3D motion capture, for example using the WISE system, can aid in understanding movement limitations, informing interventions, and monitoring progress with rehabilitation.

Estimating elbow loading conditions through the motion behaviors of subchondral bone density during joint movements

Evaluating complicated stress across the elbow under joint motion remains difficult. Here, we aimed to evaluate the distribution of the subchondral bone density in the normal elbow bones and further characterize their spatial relationships during elbow motion to estimate the loading stress across the articular surface using three-dimensional computed tomography bone models. The normal elbow joint exhibited a consistent distribution pattern of subchondral bone density. High-density regions were distributed in the capitellum and posterior humeral trochlea, sagittal ridge of the ulnar trochlear notch and ulnar-volar side of the radial head. Motion analyses revealed that the high-density regions proximate with elbow flexion with forearm pronation in the radiocapitellar joint and in the fully extended position in the ulnohumeral joint. This reasonably reflects the stress acting on the joint surface under actual loading conditions. These findings suggest that daily activities involving lifting or carrying objects in these positions are stress-prone activities.

Quantitative biomechanical analysis in validating a video-based model to remotely assess physical frailty: a potential solution to telehealth and globalized remote-patient monitoring.

Assessing physical frailty (PF) is vital for early risk detection, tailored interventions, preventive care, and efficient healthcare planning. However, traditional PF assessments are often impractical, requiring clinic visits and significant resources. We introduce a video-based frailty meter (vFM) that utilizes machine learning (ML) to assess PF indicators from a 20s exercise, facilitating remote and efficient healthcare planning. This study validates the vFM against a sensor-based frailty meter (sFM) through elbow flexion and extension exercises recorded via webcam and video conferencing app. We developed the vFM using Google's MediaPipe ML model to track elbow motion during a 20s elbow flexion and extension exercise, recorded via a standard webcam. To validate vFM, 65 participants aged 20-85 performed the exercise under single-task and dual-task conditions, the latter including counting backward from a random two-digit number. We analyzed elbow angular velocity to extract frailty indicators-slowness, weakness, rigidity, exhaustion, and unsteadiness-and compared these with sFM results using intraclass correlation coefficient analysis and Bland-Altman plots. The vFM results demonstrated high precision (0.00-7.14%) and low bias (0.00-0.09%), showing excellent agreement with sFM outcomes (ICC(2,1): 0.973-0.999), unaffected by clothing color or environmental factors. The vFM offers a quick, accurate method for remote PF assessment, surpassing previous video-based frailty assessments in accuracy and environmental robustness, particularly in estimating elbow motion as a surrogate for the 'rigidity' phenotype. This innovation simplifies PF assessments for telehealth applications, promising advancements in preventive care and healthcare planning without the need for sensors or specialized infrastructure.

Sensitivity of Cerebellar Reaching Ataxia to Kinematic and Dynamic Demands.

Individuals with cerebellar ataxia often face significant challenges in controlling reaching, especially when multijoint movements are involved. This study investigated the effects of kinematic and dynamic demands on reaching movements by individuals with cerebellar ataxia and healthy controls using a virtual reality task. Participants reached to target locations designed to elicit a range of coordination strategies between shoulder and elbow joint movements. Results showed that the cerebellar group exhibited greater trajectory curvature and variability in hand paths compared to controls, with pronounced deficits in the initial hand movement direction. Kinematic simulations indicated that early hand movement errors were sensitive to the required onset times and rates of joint movements and were most impaired when opposite direction joint movements were required (e.g., elbow extension with shoulder flexion). This highlights significant disruptions in motion planning and feedforward control in the cerebellar group. Dynamic analysis showed that cerebellar participants' movements were more impaired in reaching directions where interaction torques normally assist the desired elbow and shoulder movements, which required them to rely more on muscle torques to move. These reach directions were also those that required opposite direction joint movements. Overall, our data suggest that reaching deficits in cerebellar ataxia result from 1) the early-phase motion planning deficits that worsen with tight timing requirements and 2) the inability to compensate for interaction torques, particularly when they assist the intended movement.

Next-gen strain sensors: Self-healing, ultra-sensitive, lightweight, and durable MWCNT-silicone rubber for advanced human motion tracking

Strain sensors that have flexible wearable forms can be applied in different aspects, such as in soft robotics, human-computer interaction, motion monitoring, and medical treatment process. The main challenge is creating lightweight, flexible sensors with high sensitivity. In this study, we developed flexible strain sensors using a simple sandwich manufacturing method. To achieve this, multi-walled carbon nanotubes (MWCNTs) were chosen for their excellent conductivity, while silicone rubber (SR) provided a flexible and durable substrate. Advanced SEM-EDX and FTIR analyses were conducted to assess the material structure. Furthermore, the electromechanical performance of the sensors was thoroughly evaluated, highlighting their potential in real-world applications. Electromechanical performance evaluation showed that the SR/0.7-MWCNT/SR sensor in the 0–90 % strain range had a sensitivity of 34.47, an increase of 53.35 %, and a linearity of 0.978, an increase of 10 % compared to the SR/0.5-MWCNT/SR sensor. In addition, the sensor has extremely fast response and recovery times of 65 ms and 60 ms, respectively. The sensor is also able to withstand up to 1.200 cycles of stretching, twisting, and bending. The sensor also exhibited good autonomous electromechanical self-healing properties against physical damage. The sensor developed in the present study are proven to be used to detect human movements such as finger bending, wrist, elbow, and knee movements.

Does Early Continuous Passive Motion Improves Effectiveness of Physical Therapy After Arthroscopic Release of Elbow Contracture: A Prospective Randomized Trial.

To investigate the effectiveness of early continuous passive motion combined with physical therapy compared to physical therapy alone as the rehabilitation protocol after the release of elbow contracture. In this randomized controlled trial, 61 patients were randomly assigned to two groups (31 in the early continuous passive motion with physical therapy group vs. 30 in the physical therapy group). The patients received rehabilitation with or without early continuous passive motion for 4 weeks and were followed up for 6 months. The outcome measures were the range of motion and Mayo Elbow Performance Score. The early continuous passive motion with physical therapy group demonstrated statistically significant improvements in range of motion and the Mayo Elbow Performance Score compared with the physical therapy group at 6 weeks, 3 months, and 6 months postoperatively. These differences were not observed in the stability subscale of the Mayo Elbow Performance Score at any of the assessed time points, nor in its pain subscale at 6 months. Compared with physical therapy alone, early continuous passive motion combined with physical therapy enabled a quicker recovery of functional elbow motion and early pain control within the 6-month follow-up after arthroscopic release of elbow contracture.

Bado type III Monteggia fractures have a high injury- and treatment-related complication rate: a single center study of 73 fractures.

Monteggia fractures can be problematic injuries. The aim of this population-based study is to evaluate the risk of complications according to the Bado types, clinical outcome, and incidence. 72 children (median age 6, range 2-11 years) with 73 Monteggia fractures treated during 2014-2022 were identified from the institutional fracture register. Timing of diagnosis, complications, and method of treatment were registered. Outcomes were assessed at mean 4 years (1-9) follow-up in 68 (94%) children. The census population (< 16 years old) in Helsinki metropolitan area during the study period was assessed. Bado types I (n = 43) and III (n = 27) comprised all but 3 of the fractures. Diagnosis was made on admission in 57, and with a 1-8-day delay in 16 children. 8 children had sustained an associated nerve injury. 35 children were treated operatively, 7 after failed closed treatment. 4 reoperations were performed, including 3 ulnar osteotomies. The risk of complications (odds ratio [OR] 4.9, 95% confidence interval [CI] 1.7-14) and closed treatment failures (OR 12.3, CI 1.3-118) was higher in Bado type III than in type I injuries. 60 children attended for clinical follow-up, all had congruent radio-humeral joints and full range of elbow and forearm motion. Mean PedsQL was 94 (72-100) and QuickDash 3 (0-13). 8 additional children reported normal elbow functions by phone. The calculated mean annual incidence of Monteggia injuries was 2.9/100,000 children. Monteggia fractures are rare (2.9/100,000 yearly). Bado type III injuries are associated with a high risk of complications.

Three-dimensional MRI analysis of elbow anatomy and kinematics in children with ulnar dimelia.

Ulnar dimelia often presents with restricted elbow movement. To develop a treatment strategy to improve elbow mobility, a detailed understanding of the skeletal deformity is needed. We created 3-D models of the cartilage and bone in the elbows of four children with ulnar dimelia by segmentation of MRI scans. We analysed the anatomy and performed a kinematic analysis. In all four children, the distal humerus was triangular in shape and consisted of a medial epicondyle, an enlarged lateral epicondyle and an anterior epicondyle. By comparing the 3-D images with conventional radiographs, we found that the projection of the enlarged lateral epicondyle created two longitudinal lines, which is a radiographic hallmark feature of the triangular-shaped distal humerus. In addition, during elbow flexion, the radial forearm bone slides along the lateral trochlea rather than rotates. This knowledge can aid surgeons to plan treatment for improving elbow mobility in ulnar dimelia.Level of evidence: IV.

Association of Clinical Findings With Complications in the Cubitus Varus Deformity After Supracondylar Fracture.

Cubitus varus deformity is primarily a cosmetic complaint that causes some early and late complications. However, no studies have reported the cubitus varus deformity regarding the frequency of complications, relationship to the degree of deformity, and period from the occurrence of the initial injury. Overall, 83 patients with cubitus varus deformity were examined. The differences in the humerus-elbow-wrist angle (∆HEW-A), tilting angle (∆TA), and internal rotation angle (∆IRA) between the affected and normal sides were measured to determine varus and extension and internal rotation deformity. The period from the occurrence of the initial injury to the evaluation date was also investigated. Multivariate logistic regression analysis was conducted to identify the explanatory variables (period, ∆HEW-A, ∆TA, and ∆IRA) independently associated with complication events. Receiver-operating characteristic curve analysis was also conducted to predict the risk of events. ∆HEW-A was independently associated with the risk of cosmetic complaint (odds ratio [OR], 1.171; 95% confidence interval [95% CI], 1.056 to 1.336) and instability (OR, 1.111; 95% CI, 1.028 to 1.200). ∆TA was independently associated with the risk of limited elbow motion (OR, 1.176; 95% CI, 1.077 to 1.285) and sports disability (OR, 0.892; 95% CI, 0.836 to 0.952). The period from the occurrence of the initial injury was independently associated with risk of pain (OR, 1.063; 95% CI, 1.019 to 1.108), ulnar nerve neuropathy (OR, 1.065; 95% CI, 1.011 to 1.125), and osteoarthritis (OR, 1.188; 95% CI, 1.098 to 1.286). The receiver-operating characteristic curve analysis revealed the optimal cutoffs of 20° and 27° for ∆HEW-A to predict cosmetic complaint and instability; of 25° for ∆TA to predict limited elbow motion; and of 8.8, 8.0, and 16.0 years for the period to predict pain, ulnar nerve neuropathy, and osteoarthritis, respectively. The treatment of cubitus varus deformity should be determined because a residual deformity >20° of varus and 25° of extension could develop risk of complications over time.

Fracture Patterns, Outcomes, and Complications of Terrible Triad Injury in Elderly Patients

AimsThe aim of this study was to describe the fracture patterns of terrible triad elbow injury (TTEI) and to evaluate complications, functional and radiographic outcomes in mid-term follow-up in patients older than 65 years. MethodsA retrospective study of 29 patients, mean follow-up of 48.7±4.6 months (range 65-78). Fractures were classified according to the Mason and Regan-Morrey classifications. All patients were evaluated by the Mayo Elbow Performance Scale (MEPS), Quick-Dash, EQVAS, EQ5D scores, and ROM measurement. ResultsThe mean age was 72.3 years and 79% were women. Mason Type III (72%) and Reagan-Morrey type II (69%) were the most frequent fracture type. All patients were managed with a lateral approach consisting of repair or replacement of the radial head and repair of the lateral ulnar collateral ligament (LUCL); of these patients, 19 underwent re-attachment of the coronoid process or anterior capsule. Mean functional scores were MEPS 90.3±7.5, Quick-DASH 18.4±4.6, EQ5D .89± 0.33, EQ-VAS 86.2 ± 21, and VAS 2.2± 1.5. Mean postoperative flexo-extension arc of elbow motion was 105º (range, 65º-145º). Two patients (7%) required revision surgery. We did not observe any joint instability in the elbow after surgery. ConclusionsPatients over 65 years old with a terrible triad elbow injury (TTEI) are at substantial risk of complex fracture patterns, particularly Mason type III radial head fractures and Regan-Morrey type II coronoid fractures. Complications such as joint stiffness and heterotopic ossification are infrequent, while associated capitellum fractures are not rare and should be considered in the assessment as they can impact elbow stability. Despite these challenges, surgical management generally achieves favorable functional outcomes with low complication and reoperation rates.

Enhancing Personalized Rehabilitation: Integrating Assist-as-Needed System With Real-Time Feedback

Abstract Conventional rehabilitation programs often lack precise real-time feedback, leading to varied training results at different centers. To address this, personalized rehabilitation strategies have been developed using robotic technologies and exoskeletons with assist-as-needed (AAN) controllers to improve recovery rates for individuals with stroke and neuromuscular disorders. This research introduces an automated therapy approach with a patient-specific AAN support strategy that provides immediate feedback, enhancing the rehabilitation process. The system uses minimal data to create effective personalized models and integrates sensors and algorithms for continuous monitoring, improving the efficacy of therapy. Initial trials with an exoskeleton that focused on elbow movements showed promising results in adjusting support in real-time and providing personalized interventions through torque-controlled motors. This system assesses impairment levels, visualizes motor energy needs, and helps design customized rehabilitation programs, significantly enhancing therapeutic results.

Flexible and Multifunctional Pressure/Gas Sensors with Polypyrrole-Coated TPU Hierarchical Array.

A promising strategy is proposed for fabricating flexible pressure/gas sensors, which have a microprotuberance and microwrinkle structure at micropillars on their sensing substrates. The sensing substrates were prepared by compression molding thermoplastic polyurethane (TPU; an industrial grade polymer) and subsequent pyrrole polymerization. Benefiting from the hierarchical structure on the sensing substrates, the flexible sensors exhibit high performances in detecting both pressure and ammonia (NH3). Mechanism for the functionalities of the hierarchical structure of the pressure sensors was analyzed. Such unique hierarchical structure endows the interlocked pressure sensor by assembling the substrates prepared at 60 min polymerization time with a relatively high sensitivity in a wider linearity range (1.15 kPa-1, 0-800 Pa), a lower detection limit of 6.2 Pa, and shorter response and recovery times (26/28 ms). The combination of stronger interfacial interaction between the TPU and polypyrrole layer, the mutual support of the interlocked micropillars, and the inherent high resilience of TPU endows the pressure sensor with lower hysteresis, good repeatability and stability, and higher durability (10,000 cycles). The interlocked pressure sensor can detect full-range human physiological activities from weak physiological signals (such as face muscle contraction, heartbeat, and breath) to body movements (such as head, elbow, and foot movement). The gas sensor assembled with the hierarchical sensing substrate prepared at 60 min polymerization time exhibits selective, stable, and faster sensing responses to NH3. The proposed facile and cost-effective preparation strategy can be an excellent candidate for fabricating high-performance and multifunctional sensors.

Using markerless motion capture and musculoskeletal models: An evaluation of joint kinematics.

This study presents a comprehensive comparison between a marker-based motion capture system (MMC) and a video-based motion capture system (VMC) in the context of kinematic analysis using musculoskeletal models. Focusing on joint angles, the study aimed to evaluate the accuracy of VMC as a viable alternative for biomechanical research. Eighteen healthy subjects performed isolated movements with 17 joint degrees of freedom, and their kinematic data were collected using both an MMC and a VMC setup. The kinematic data were entered into the AnyBody Modelling System, which enables the calculation of joint angles. The mean absolute error (MAE) was calculated to quantify the deviations between the two systems. The results showed good agreement between VMC and MMC at several joint angles. In particular, the shoulder, hip and knee joints showed small deviations in kinematics with MAE values of 4.8∘, 6.8∘ and 3.5∘, respectively. However, the study revealed problems in tracking hand and elbow movements, resulting in higher MAE values of 13.7∘ and 27.7∘. Deviations were also higher for head and thoracic movements. Overall, VMC showed promising results for lower body and shoulder kinematics. However, the tracking of the wrist and pelvis still needs to be refined. The research results provide a basis for further investigations that promote the fusion of VMC and musculoskeletal models.

The recovery and independence of elbow flexion and forearm supination after Oberlin II transfer in brachial plexus injuries: a long term follows up study.

The Oberlin II double fascicular nerve transfer has been evaluated extensively for objective outcomes for elbow flexion in brachial plexus injuries (BPI). However, there is limited information available on the recovery pattern of supination and patient-reported activity in the long-term. Our study aimed to assess the functional results with a minimum of five years of follow-up. We evaluated patients with a minimum of five years after the Oberlin II procedure for post-traumatic BPI. They were evaluated using MRC grading, range of active movements, QuickDASH score and activity to check elbow flexion and forearm supination independent of finger and wrist flexion. 18 out of 26 patients responded with a mean follow-up of 79.4months (range: 61-98). 16 (88.9%) (p < 0.000) patients recovered to achieve active elbow flexion and forearm supination of either MRC grade 3 power or more. The average range of active elbow flexion was 113.9° (range: 0-140°) and active supination was 67.8° (0-90°). Patients who achieved grade 3 flexion or higher were found to regain supination after a delay. The recovery continues even after two years of surgery. The mean QuickDASH score was 21.8 (range: 2.3-63.6). There's a significant inverse correlation between QuickDASH with both flexion and supination (p < .001 and < 0.05). 15 patients (83.3%) could demonstrate a dissociation of elbow and forearm movements from digital and wrist movements. Our study demonstrated reliable functional results with independent elbow flexion, forearm supination and acceptable patient-reported outcomes for Oberlin II procedure in BPI.

Self‐healing, adhesive, photothermal responsive, stretchable, and strain‐sensitive supramolecular nanocomposite hydrogels based on host–guest interactions

AbstractThe development of multifunctional supramolecular nanocomposite hydrogels remains challenging. Here, the dynamic host–guest interactions involving the host molecule CB[8] and guest units were utilized to prepare Fe3O4 hybrid supramolecular nanocomposite hydrogels. The results showed that the hydrogels obtained possessed a porous structure. The CB[8]‐modified Fe3O4 (Fe3O4@CB[8]) nanoparticles served as cross‐linkers in forming the network of hydrogels. By adjusting the Fe3O4@CB[8] content, the mechanical properties of the hydrogels could be controlled. The tensile stress was measured at 160 kPa with a fracture strain of 1380%, while the compression stress was 230 kPa at 70% compression strain. The self‐healing efficiency of the hydrogels at room temperature reached 95% after 24 h. The as‐obtained hydrogels show strain sensitivity and have the potential for applications in detecting elbow and finger movements. Our supramolecular nanocomposite hydrogels exhibit multiple functions, including self‐healing, injectability, photothermal responsiveness, and conductivity, making them suitable for integration into flexible electronics.Highlights Fe3O4@CB[8] nanoparticles serve as cross‐linkers for the nanocomposite hydrogels. CB[8] based host–guest interactions enable hydrogels to self‐heal. Fe3O4@CB[8] endow hydrogels with stretchability and photothermal responsiveness. Hydrogels exhibit injectability, NIR responsiveness, and conductive ability.