Search Results (40)

Stroke is a leading cause of disability, often resulting in motor, cognitive, and language deficits, with significant impact on upper-limb function. Robotic therapy (RT) has emerged as an effective strategy, providing intensive, repetitive, and adaptable practice to optimize functional recovery. This pilot study aimed to describe and evaluate the effects of robotic rehabilitation as a complement to conventional therapy, using a biomimetic activities-of-daily-living (ADL)-based protocol, on upper-limb function in post-stroke patients. Three participants (aged 30–80 years) undergoing occupational and/or physiotherapy received individualized robotic training with a lightweight cable-driven upper-limb exoskeleton, m-FLEX™, twice a week for ten weeks (30 min per session). Movements were designed to mimic natural upper-limb actions, including elbow flexion-extension, forearm pronation-supination, tripod pinch, and functional tasks such as grasping a cup. Assessments included the Fugl-Meyer (FM) scale, the Functional Independence Measure (FIM), and device satisfaction, performed at baseline, mid-intervention, and post-intervention. Descriptive analysis of the tabulated data revealed improvements in range of motion and functional outcomes. These findings suggest that biomimetic protocol of robotic rehabilitation, when combined with conventional therapy, can enhance motor and functional recovery in post-stroke patients. Full article

Background: Trapeziometacarpal osteoarthritis (TMC OA) is a prevalent degenerative disorder that causes considerable pain and functional limitations, especially in older individuals, whose ideal treatment is still debated in the literature. Various treatments are described to restore a good functional outcome of the thumb; over the past 50 years, biological arthroplasties have been considered the gold standard for treating advanced stages of TMC OA. However, in the last decade, the use of dual mobility cup prostheses has significantly increased, with numerous studies reporting excellent clinical outcomes. In this case report, we show the results of a patient treated on the left hand with suspension arthroplasty and on his right hand with dual mobility arthroplasty in one-stage surgery. The aim of this case report is to directly compare outcomes between trapeziometacarpal prosthesis and suspension arthroplasty performed simultaneously in the same patient. Case Presentation: The present case reports a 71-year-old male patient with bilateral TMC osteoarthritis, referred to our clinic in May 2024. His medical history included hypertension, hypertriglyceridemia, paroxysmal atrial fibrillation, and benign prostatic hyperplasia. On examination, the right hand showed grade 3 osteoarthritis according to the Eaton–Littler classification, with the trapezium maintaining adequate bone stock, making the patient eligible for trapeziometacarpal prosthesis implantation. Conversely, the left hand demonstrated scaphotrapezoid arthritis with a slight reduction in trapezial bone stock, indicating the need for trapeziectomy followed by suspension arthroplasty. Both procedures were performed during the same surgical session by the same experienced hand surgeon using a lateral approach. On the right side, the trapeziometacarpal joint surfaces were resected and replaced with a dual mobility prosthesis, while on the left side, the trapezium was excised, and suspension arthroplasty was performed using a slip of the flexor carpi radialis (FCR) tendon. Methods: The patient underwent simultaneous treatment with a dual mobility trapeziometacarpal prosthesis on the right hand and trapeziectomy with suspension arthroplasty on the left hand. Clinical outcomes (grip and pinch strength, pain, QuickDASH, satisfaction, and range of motion) were evaluated at 1, 3, 6, and 12 months. Paired comparative statistics were applied with significance set at p < 0.05. Results: At all follow-up intervals (1, 3, 6, and 12 months), the hand treated with a trapeziometacarpal prosthesis demonstrated superior grip and pinch strength compared to the hand treated with trapeziectomy and suspension arthroplasty, with the greatest difference observed at 3 months. At 12 months, grip strength increased from 28 kg to 40 kg in the prosthesis-treated hand and from 25 kg to 33 kg in the suspension arthroplasty hand. Paired comparisons were performed at each follow-up interval up to 12 months, confirming a significant difference for grip strength. Pain levels (VAS, Visual Analogue Scale) decreased progressively in both hands, with a more rapid reduction in the hand treated with a trapeziometacarpal prosthesis, reaching statistical significance. QuickDASH scores indicated an earlier return to daily activities in the hand treated with the prosthesis, although this difference was not statistically significant. Patient satisfaction was consistently higher for the hand treated with a trapeziometacarpal prosthesis, with the patient reporting a ‘very satisfied’ rating at all timepoints. Range of motion recovery, assessed through the Kapandji score and measurements of thumb abduction and extension, also favored the hand treated with the prosthesis, with statistically significant differences for abduction and extension, whereas the hand treated with trapeziectomy and suspension arthroplasty demonstrated more gradual improvement over time. Conclusions: This case highlights the functional efficacy of both surgical approaches—biological arthroplasty and trapeziometacarpal prosthesis—in the treatment of TMC osteoarthritis. Both procedures resulted in a good clinical outcome and high patient satisfaction. However, recovery was noticeably faster in the hand treated with a trapeziometacarpal prosthesis, which is consistent with findings previously reported in the literature. These observations suggest that, while both techniques are valid and effective, trapeziometacarpal prosthetic replacement may offer a quicker return to function in appropriately selected patients. Full article

Highly sensitive bioinspired cutaneous receptors are essential for realistic human-robot interaction. This study presents a biomimetic tactile sensor morphologically modeled after the Meissner corpuscle, designed for high dynamic sensitivity achieved using a coiled configuration. Our proposed electrolytic polymerization technique with magnet-responsive hybrid fluid (HF) was employed to fabricate soft, elastic rubber sensors with embedded coiled electrodes. The coiled configuration, optimized by electrolytic polymerization, exhibited high responsiveness to dynamic motions including pressing, pinching, twisting, bending, and shearing. The mechanism of the haptic property was analyzed by electrochemical impedance spectroscopy (EIS), revealing that reactance variations define an equivalent electric circuit (EEC) whose resistance (R_p), capacitance (C_p), and inductance (L_p) change with applied force; these changes correspond to mechanical deformation and the resulting variation in the sensor’s built-in voltage. The roll-type Meissner-inspired sensor demonstrated fast-adapting behavior and broadband vibratory sensitivity, indicating its potential for high-performance tactile and auditory sensing. These findings confirm the feasibility of electrolytically polymerized hybrid fluid rubber as a platform for next-generation bioinspired haptic interfaces. Full article

Contacted liquid fluids, in most cases, have the tendency to directly merge into a single larger fluid to minimize the surface energy. We present an abnormal drop formation process of contacted Cu liquid films with a radius of 101.7 Å or larger on carbon substrates by using molecular dynamics simulations. The formation process consists of consecutive pinch-off and full coalescence stages connected by detachment. The dominant motions of the bridge, away from the center and downward to the substrate, lead to the pinch-off of the initially connected droplets. The motions of the droplets, which are near each other at all times, leads to the repeated contact and full coalescence of the separated droplets. The abnormality is attributed to the competition between the motions of the droplets and the tiny liquid bridge that connects the droplets. The influence of the surface structures of substrates, especially carbon nanotubes, on the formation behavior is discussed by analyzing the mean square displacement, velocity fields, and density and scaling profiles. This study provides guidance for controlling drop formation behavior by regulating the surface structures of carbon substrates. Full article

The lack of deep engagement strategies that include cultural contextualization in the current rehabilitation game design can result in limited user motivation and low adherence in long-term rehabilitation. Integrating cultural semantics into interactive rehabilitation design offers new opportunities to enhance user engagement and emotional resonance in digital rehabilitation therapy, especially in a deeper way rather than visually. This study introduces a framework comprising a “Rehabilitation Mechanism–Interaction Design–Cultural Feature” triadic mapping model and a structured procedure. Following the framework, a hand function rehabilitation game is designed based on Chinese string puppetry, as well body rehabilitation games based on shadow puppetry and Tai Chi. The hand rehabilitation game utilizes Leap Motion for its gesture-based input and Unity3D for real-time visual feedback and task execution. Functional training gestures such as grasping, wrist rotation, and pinching are mapped to culturally meaningful puppet actions within the game. Through task-oriented engagement and narrative immersion, the design improves cognitive accessibility, emotional motivation, and sustained participation. Evaluations are conducted from rehabilitation professionals and target users. The results demonstrate that the system is promising in integrating motor function training with emotional engagement, validating the feasibility of the proposed triadic mapping framework in rehabilitation game design. This study provides a replicable design strategy for human–computer interaction (HCI) researchers working at the intersection of healthcare, cultural heritage, and interactive media. Full article

Near-nozzle atomization characteristics in air-assisted spraying were investigated through a novel 3D transient model integrating Volume-of-Fluid and Large Eddy Simulation (VOF-DPM) methods, with experimental validation of droplet distributions (Malvern analyzer) and coating thickness profiles. Key findings reveal that (1) the spray field stabilizes within 30 mm downstream, achieving 80% atomization efficiency (droplets ≤ 100 μm) at 27.5 mm axial distance; (2) radial momentum originates dually from fan-shaped airflow (max 595 m/s) and transverse motion induced by central atomizing air entrainment—a previously unreported mechanism; (3) paint loading delays flow stabilization to 2.5 ms (vs. 0.7 ms for gas-only flow) while reducing peak axial velocity by 18%–22% due to gas–liquid momentum exchange; (4) auxiliary and fan airflows synergistically constrain dispersion, forming elliptical sprays with characteristic cone angles of 61.7° (short axis) and 99.1° (long axis). Significantly, surface tension plays a dual role in inhibiting droplet atomization while promoting ligament pinch-off at 8.1 mm breakup length. These results provide the first quantitative characterization of gas–liquid interactions in near-nozzle regions, enabling precise parameter control for enhanced coating uniformity on complex surfaces. Full article

With the growing use of head-mounted displays (HMDs) such as smart glasses, text input remains a challenge, especially in mobile environments. Conventional methods like physical keyboards, voice recognition, and virtual keyboards each have limitations—physical keyboards lack portability, voice input has privacy concerns, and virtual keyboards struggle with accuracy due to a lack of tactile feedback. FlickPose is a novel text input system designed for smart glasses and mobile HMD users, integrating flick-based input and hand pose recognition. It features two key selection methods: the touch-panel method, where users tap a floating UI panel to select characters, and the raycast method, where users point a virtual ray from their wrist and confirm input via a pinch motion. FlickPose uses five left-hand poses to select characters. A machine learning model trained for hand pose recognition outperforms Random Forest and LightGBM models in accuracy and consistency. FlickPose was tested against the standard virtual keyboard of Meta Quest 3 in three tasks (hiragana, alphanumeric, and kanji input). Results showed that raycast had the lowest error rate, reducing unintended key presses; touch-panel had more deletions, likely due to misjudgments in key selection; and frequent HMD users preferred raycast, as it maintained input accuracy while allowing users to monitor their text. A key feature of FlickPose is adaptive tracking, which ensures the keyboard follows user movement. While further refinements in hand pose recognition are needed, the system provides an efficient, mobile-friendly alternative for HMD text input. Future research will explore real-world application compatibility and improve usability in dynamic environments. Full article

The advent of mixed reality (MR) systems has revolutionized human–computer interactions by seamlessly integrating virtual elements with the real world. Devices like the HoloLens 2 (HL2) enable intuitive, hands-free interactions through advanced hand-tracking technology, making them valuable in fields such as education, healthcare, engineering, and training simulations. However, despite the growing adoption of MR, there is a noticeable lack of comprehensive comparisons between the hand-tracking accuracy of the HL2 and high-precision benchmarks like motion capture systems. Such evaluations are essential to assess the reliability of MR interactions, identify potential tracking limitations, and improve the overall precision of hand-based input in immersive applications. This study aims to assess the accuracy of HL2 in tracking hand position and measuring kinematic hand parameters, including joint angles and lateral pinch span (distance between thumb and index fingertips), using its tracking data. To achieve this, the Vicon motion capture system (VM) was used as a gold-standard reference. Three tasks were designed: (1) finger tracing of a 2D pattern in 3D space, (2) grasping various common objects, and (3) lateral pinching of objects with varying sizes. Task 1 tests fingertip tracking, Task 2 evaluates joint angle accuracy, and Task 3 examines the accuracy of pinch span measurement. In all tasks, HL2 and VM simultaneously recorded hand positions and movements. The data captured in Task 1 were analyzed to evaluate HL2’s hand-tracking capabilities against VM. Finger rotation angles from Task 2 and lateral pinch span from Task 3 were then used to assess HL2’s accuracy compared to VM. The results indicate that the HL2 exhibits millimeter-level errors compared to Vicon’s tracking system in Task 1, spanning in a range from 2 mm to 4 mm, suggesting that HL2’s hand-tracking system demonstrates good accuracy. Additionally, the reconstructed grasping positions in Task 2 from both systems show a strong correlation and an average error of 5°, while in Task 3, the accuracy of the HL2 is comparable to that of VM, improving performance as the object thickness increases. Full article

Background: Carpometacarpal thumb arthritis causes pain and functional limitations. Methods: This study evaluated the efficacy of arthroscopic partial trapeziectomy with free palmar longus tendon suspension and interpositional arthroplasty, combined with a soft anchor internal brace, for the treatment of thumb basal joint arthritis. Between August 2010 and April 2020, 60 thumbs with symptomatic basal joint arthritis (Eaton stage II–III) were treated using this minimally invasive technique. Results: The cohort included 52 female and 8 male patients (mean age, 62.6 ± 4.3 years), who underwent clinical follow-up for 28.7 ± 3.0 months. VAS pain scores decreased from 5.7 ± 0.5 to 1.0 ± 0.7 and 7.1 ± 0.6 to 1.4 ± 0.9 (p < 0.001) during rest and activity, respectively. Thumb range of motion increased from 43.3 ± 11.3 to 54.2 ± 9.8 degrees, while pinch strength improved from 47.3 ± 9.5% to 88.8 ± 17.3% of the contralateral side (p < 0.001). Patients with Eaton stage II disease demonstrated better outcomes than those with stage III disease. Radiographically, minimal proximal migration of the first metacarpal (mean, 1.2 mm) was observed, with no cases of scaphotrapezial joint arthritis. Conclusions: Arthroscopic partial trapeziectomy with tendon suspension/interposition and an internal brace is an effective treatment for Eaton stage II–III basal joint arthritis, offering significant pain relief, functional improvement, and joint stability, while preserving the scaphotrapezial joint. Full article

Background/Objectives: Atrophic nonunion presents a significant challenge in hand surgery, often resulting in chronic pain and functional disability. Traditional surgical treatments such as bone grafting and internal fixation may be insufficient. This study evaluates the feasibility, safety, and preliminary effectiveness of a regenerative-first surgical protocol that combines autologous bone micro-grafts with a fresh human amniotic membrane to create a biologically active regenerative chamber. Methods: A total of 8 patients (6 males, 2 females; age range: 22–56 years) with an atrophic nonunion of metacarpals and phalanges were treated using a regenerative-first surgical approach. Autologous bone was harvested from the iliac crest and mechanically disaggregated via Rigenera^® technology to obtain micro-grafts enriched with osteoprogenitor cells and extracellular matrix fragments. These were applied to the bone defect and wrapped in a fresh amniotic membrane, creating a biologically active chamber. Fixation was achieved using low-profile plates or screws, and all patients underwent early protected mobilization. Results: Radiographic consolidation was achieved in all patients within 2 months postoperatively. Functional outcomes at final follow-up demonstrated excellent or good results in Total Active Motion (TAM), with grip and pinch strength within normative ranges and minimal residual pain. Conclusions: This preliminary series suggests that combining autologous bone micro-grafts with an amniotic membrane in a regenerative surgical protocol is a promising strategy for managing atrophic nonunion in the hand. The approach was associated with rapid consolidation and excellent functional recovery. Further research with larger, controlled cohorts is warranted to validate efficacy and define standardized indications and techniques. Full article

Background: Trapeziometacarpal (TM) joint arthritis is a common condition causing pain and functional limitations, particularly in activities requiring pinch and grip strength. Surgical options such as interposition trapeziectomy and prosthetic joint replacement have demonstrated varying degrees of success. However, the role of post-operative rehabilitation in optimizing outcomes for these procedures remains underexplored. Effective rehabilitation may be critical for restoring strength, range of motion (ROM), and overall hand function; yet, no consensus exists on the best approach for either surgical modality. This study aims to evaluate the impact of post-operative rehabilitation on functional and clinical outcomes in patients undergoing interposition trapeziectomy versus prosthetic replacement for TM joint arthritis. Methods: A retrospective cohort study was conducted on patients treated for TM joint arthritis between November 2023 and October 2024. Patients were divided into two groups based on the surgical procedure: interposition trapeziectomy and prosthetic replacement. Patients randomly followed post-operative rehabilitation protocols, auto-assisted exercises, or no type of rehabilitation. The outcomes assessed included pain (VAS), return to work or heavy activities, post-operative complications, hand function (DASH score), and patient satisfaction at 1 and 6 months after surgery. Results: The prosthesis group consisted of 30 patients, while 31 patients underwent interposition trapeziectomy. Patients in both groups showed good improvements in pain, ROM, and hand function post rehabilitation. The prosthetic group demonstrated a faster recovery of strength and higher early satisfaction scores, but in the long term, the results were overlapping. No significant differences were observed in long-term functional outcomes or patient satisfaction at 6 months. In the trapeziectomy group, for patients who followed a rehabilitation program, no significant differences were found. Conclusions: Post-operative rehabilitation finds its place in recovery after both interposition trapeziectomy and prosthetic replacement for TM joint arthritis. While prosthetic replacement allows for quicker functional recovery, interposition trapeziectomy offers comparable long-term results with a lower complication profile. Tailored rehabilitation protocols may enhance outcomes and should be considered an integral part of TM joint arthritis management in selected patients. Full article

Trapeziometacarpal osteoarthritis is the second most frequent degenerative hand disease, and it presents in 66% of women over the age of 55. Post-surgery immobilization results in functional losses that could be attenuated by motor imagery training. Objectives: The aim of this study is to evaluate the efficacy of motor imagery training during the post-surgical immobilization period in women who underwent surgery for trapeziometacarpal osteoarthritis. Methods: A randomized controlled trial was performed. A total of 40 patients satisfied the eligibility criteria, agreed to participate, and were randomized into an experimental group (n = 20) or control group (n = 20). Motor imagery was applied to the experimental group during the 3 weeks of post-surgical immobilization and to the control group with the conventional protocol. Measurement outcomes were assessed four times throughout the study using the Disabilities of the Arm, Shoulder, and Hand questionnaire, the Cochin Hand Function Scale questionnaire, the Visual Analogue Scale, goniometry, a baseline pinch gauge, circumferential measurement, and the modified Kapandji Index. Results: There were significant improvements in the motor imagery group compared with the control group in post-motor imagery, pre- and post-rehabilitation measurements, functional pain (p < 0.001), rest pain (p < 0.01), hand mobility (p < 0.001), range of motion (p < 0.05), and wrist edema (p < 0.04); there were also improvements in pre- and post-rehabilitation measurements, quality of life in relation to upper limb function problems (p < 0.04), the post-rehabilitation measurement of hand functionality (p = 0.02), and post-motor imaging in finger-to-finger pinch strength. There were no statistically significant differences in the rest of the variables. Conclusions: Early intervention with motor imagery could be effective for resting and functional pain, quality of life in relation to upper limb problems, functional capacity, mobility, range of motion, strength, and edema. Full article

This study investigates the seismic performance of substandard reinforced concrete (RC) frames, particularly emphasizing the behavior of beam–column joints through comprehensive shake table testing. Historical evidence indicates that RC structures erected prior to the 1970s frequently exhibit critical deficiencies in shear reinforcement, significantly undermining their seismic resilience. The primary objective of this research is to experimentally quantify the shear capacity, deformability, and failure mechanisms of beam–column joints within substandard RC frames. Shake table experiments were conducted on a meticulously scaled (one-third scale), single-story, single-bay RC frame, representative of construction practices typical of 1980s Türkiye. The input seismic loading was derived and scaled from the recorded ground motions of the 2023 Kahramanmaraş earthquake to ensure realistic seismic demand conditions. Experimental outcomes revealed a maximum lateral displacement of 53.1 mm, corresponding to a story drift ratio of approximately 0.055 radians and a computed damage index of 0.758, indicative of near-collapse performance levels. Notable damage observations included extensive shear cracking and concrete spalling at beam–column interfaces, accompanied by pronounced pinching effects during cyclic loading. The findings emphasize an urgent need for targeted seismic retrofit solutions, specifically addressing shear vulnerabilities in beam–column joints. Furthermore, the results carry substantial implications for revising current seismic design codes and enhancing the earthquake resilience of existing RC infrastructure in seismic-prone regions. Full article

Trapeziometacarpal joint osteoarthritis (TMJ OA) is a progressive condition, particularly affecting postmenopausal women. Various surgical techniques have been proposed, but the optimal approach remains debated. This clinical study compares the clinical, functional, and radiological outcomes of two surgical treatments: suspension tenoplasty using the flexor carpi radialis tendon (Altissimi technique, AST) and a dual-mobility prosthesis. The main complications associated with these procedures include postoperative pain, De Quervain’s syndrome, radial nerve injuries, and prosthetic component mobilization. In prosthetic arthroplasty, the most common complication is component mobilization (8%), while in tenoplasty, postoperative pain is the most frequent (15%). A total of 36 patients were randomized into two groups: 18 patients underwent AST (Group A), and 18 received trapeziometacarpal joint arthroplasty (Group B). Functional outcomes were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH), Visual Analogue Score (VAS), and Michigan Hand Outcomes Questionnaire (MHQ) at 3, 6, 12, and 24 months. Range of motion (ROM), Kapandji score, pulp pinch strength, hand grip strength (Jamar dynamometer), and radiological maintenance of the trapezial space (step-off measurement) were also evaluated. Both procedures resulted in significant pain reduction (VAS, p < 0.05) and functional improvement (DASH, MHQ, p < 0.05). ROM increased significantly in both groups. The Kapandji scores improved from 4.0 ± 1.1 to 9.2 ± 1.2 (Group A) and 4.3 ± 0.8 to 7.8 ± 1.4 (Group B) (p < 0.05). Group B grip strength results showed a greater increase in hand grip strength than Group A (p = 0.23). The radiographic step-off showed slight proximal migration of the first metacarpal in Group A, whereas Group B maintained joint height. No implant loosening or major complications were reported in either group. Both suspension tenoplasty and dual-mobility arthroplasty are effective in TMJ OA. AST ensures joint stability with minimal radiographic changes, whereas TJA provides superior grip strength and ROM recovery. The absence of major complications suggests that TJA is a safe alternative to AST, but its higher cost and potential for implant-related complications must be considered. Full article

Background/Objectives: An Extensor Pollicis Longus (EPL) subcutaneous rupture is a substantial complication in post-traumatic or degenerative wrist and tendinous lesions. The diagnosis is essentially dictated by a clinical evaluation; in fact, it is characterized by the inability to extend the thumb interphalangeal joint and to retropose the thumb while the hand is resting on a surface. The tendinous transposition using the Extensor Indicis Proprius (EIP) as a donor tendon is a well-known surgical technique performed to restore functional activity to the thumb, and it is preferred for the closer cerebellar network with the thumb itself. However, there is a dearth of clinical results and scientific evidence in the literature. The aim of this study is to evaluate the return-to-work eligibility after an inveterate EPL subcutaneous rupture repaired with a transposition of the EIP. Methods: Patients who reported a subcutaneous rupture of the EPL due to rheumatic diseases or who had undergone previous hand or wrist surgery were excluded; however, all patients tested positive for traumatic wrist hypertension. The surgical technique involves three small incisions to achieve tenorrhaphy of the EIP at the distal head of the EPL. Dynamic tests are carried out intraoperatively to verify the tightness and sufficient rigidity of the suture. The objective evaluation involves the range of motion, pinch strength, and power extension of the thumb and the index finger. Patient-reported outcome measures for pain and patient satisfaction include the Numeric Pain Rating Scale and the Disabilities of the Arm, Shoulder, and Hand questionnaire. Results: A total of 12 patients were eligible (7 W, 5 M, mean age 56.3 years) and were followed for at least one year. There were no surgery-related complications. After the cast was removed 3 weeks after surgery, patients could extend their thumbs, put them back, and use their index fingers. An immediate improvement in objective and subjective assessments was reported. At 10 weeks, nine patients (75%) returned to full work with no pain and without the aid of rehabilitation; two patients (17%) returned to full work with no symptoms 2 weeks later; and only one patient (8%) with a neurological disease required physical therapy, achieving pain control and restoration of full mobility approximately six months after surgery. Conclusions: This surgical technique seems to address satisfactory results in terms of skill recovery and rapid return to work. A tailored rehabilitation program should be implemented for selected patients with neurological conditions that may prolong the adaptation process of the transposed tendon, the coordination, and the independent function of the thumb and index finger. Full article