Search Results (381)

Background: Seiza, a traditional sitting posture requiring deep ankle plantarflexion and knee flexion, often becomes difficult after ankle fracture surgery because of restricted mobility. Increased stiffness of the tibialis anterior (TA) muscle, particularly in its deep and superficial fibres, may limit plantarflexion and affect functional recovery. This study aimed to investigate the relationship between TA muscle stiffness, assessed using shear wave elastography (SWE), and the ability to assume the seiza posture after ankle fracture surgery. We also sought to determine whether the stiffness in the deep or superficial TA fibres was more strongly correlated with seiza ability. Methods: In this cross-sectional study, 38 patients who underwent open reduction and internal fixation for ankle fractures were evaluated 3 months postoperatively. Seiza ability was assessed using the ankle plantarflexion angle and heel–buttock distance. The shear moduli of the superficial and deep TA fibres were measured using SWE. Ankle range of motion, muscle strength, and self-reported seiza pain were also measured. Multiple linear regression was used to identify the predictors of seiza performance. Results: The shear moduli of both deep (β = −0.454, p < 0.001) and superficial (β = −0.339, p = 0.017) TA fibres independently predicted ankle plantarflexion angle during seiza (adjusted R², 0.624). Pain during seiza was significantly associated with reduced plantarflexion, whereas muscle strength was not a significant predictor. Conclusions: TA muscle stiffness, especially in the deep fibres, was significantly associated with limited postoperative seiza performance. Targeted interventions that reduce deep TA stiffness may enhance functional outcomes. Full article

Multiple Sclerosis (MS) is a chronic neurological disorder affecting the central nervous system that significantly impairs postural control and functional abilities. Robotic-assisted gait training mitigates this functional deterioration. This preliminary study aims to investigate the effects of a four-week gait training with the ExoAtlet II exoskeleton on static balance control and functional mobility in five individuals with MS (Expanded Disability Status Scale ≤ 2.5). Before and after the training, they were assessed in quiet standing under Eyes Open (EO) and Eyes Closed (EC) conditions and with the Timed Up and Go (TUG) test. Center of Pressure (CoP) Sway Area, Antero–Posterior (AP) and Medio–Lateral (ML) CoP displacement, Stay Time, and Total Instability Duration were computed. TUG test Total Duration, sit-to-stand, stand-to-sit, and linear walking phase duration were analyzed. To establish target reference values for rehabilitation advancement, the same evaluations were performed on a matched healthy cohort. After the training, an improvement in static balance with EO was observed towards HS values (reduced Sway Area, AP and ML CoP displacement, and Total Instability Duration and increased Stay Time). Enhancements under EC condition were less marked. TUG test performance improved, particularly in the stand-to-sit phase. These preliminary findings suggest functional benefits of exoskeleton gait training for individuals with MS. Full article

Work-related musculoskeletal disorders (WMSDs) are among the most prevalent occupational health issues, particularly affecting public transport drivers due to prolonged sitting, constrained postures, and poorly adaptable cabins. This study addresses the ergonomic risks associated with tram driving, aiming to evaluate biomechanical load and postural stress in relation to drivers’ anthropometric characteristics. A combined methodological approach was applied, integrating two standardized observational tools—RULA and REBA—with anthropometric modeling based on three representatives European morphotypes (SmallW, MidM, and TallM). ErgoFellow 3.0 software was used for digital posture evaluation, and lumbar moments at the L4/L5 vertebral level were calculated to estimate lumbar loading. The analysis was simulation-based, using digital human models, and no real subjects were involved. The results revealed uniform REBA (Rapid Entire Body Assessment) and RULA (Rapid Upper Limb Assessment) scores of 6 across all morphotypes, indicating moderate to high risk and a need for ergonomic intervention. Lumbar moments ranged from 51.35 Nm (SmallW) to 101.67 Nm (TallM), with the tallest model slightly exceeding the recommended ergonomic thresholds. These findings highlight a systemic mismatch between cabin design and user variability. In conclusion, ergonomic improvements such as adjustable seating, better control layout, and driver education are essential to reduce the risk of WMSDs. The study proposes a replicable methodology combining anthropometric, observational, and biomechanical tools for evaluating and improving transport workstation design. Full article

Background: Falls are a major public health issue among older adults, often related to postural or orthostatic hypotension (OH). The optimal timing and methods for measuring blood pressure (BP) to assess OH and its relationship with falls are uncertain. Methods: We analyzed data from two older cohorts: the PROHEALTH study (n = 30, aged ≥ 65 years) and the NILVAD-CBF trial (n = 58, aged ≥ 50 years). Continuous beat-to-beat BP was measured during active stand tests. We assessed orthostatic BP responses during sit-to-stand and supine-to-stand maneuvers and calculated the associations between orthostatic BP response variables and falls. Results: In the PROHEALTH cohort, participants with a history of falls exhibited a significantly lower baseline BP (115 ± 13/68 ± 10 vs. 142 ± 21/79 ± 11 mmHg; p = 0.004/0.018) and lower systolic BP (SBP) nadir (90 ± 22 vs. 112 ± 25 mmHg; p = 0.043) than non-fallers. SBP recovery within three minutes post-stand was delayed in fallers but rapid in non-fallers. A lower resting BP was associated with fall risk, and a lower BP nadir within 10 s after standing showed a trend toward a higher fall risk. No significant associations were found in the NILVAD-CBF cohort (prospective falls). Conclusions: Our findings demonstrate that a lower resting SBP and diastolic BP (DBP) are associated with an increased fall risk in older adults, with a lower SBP and DBP nadir after standing also showing a potential association. Persistent OH or delayed BP recovery is identified as a potentially relevant fall risk factor. The supine-to-stand test was more sensitive in detecting OH than the sit-to-stand test. Continuous BP monitoring provides the advantage of detecting pathophysiologic orthostatic BP responses for fall risk assessment in older adults. Further research with larger cohorts is warranted to validate our findings. Full article

This paper presents a human-in-the-loop interactive framework for skeleton-based posture recognition, designed to support model training and artistic education. A total of 4870 labeled images are used for training and validation, and 500 images are reserved for testing across five core posture categories: standing, sitting, jumping, crouching, and lying. From each image, comprehensive skeletal features are extracted, including joint coordinates, angles, limb lengths, and symmetry metrics. Multiple classification algorithms—traditional (KNN, SVM, Random Forest) and deep learning-based (LSTM, Transformer)—are compared to identify effective combinations of features and models. Experimental results show that deep learning models achieve superior accuracy on complex postures, while traditional models remain competitive with low-dimensional features. Beyond classification, the system integrates posture recognition with a visual recommendation module. Recognized poses are used to retrieve matched examples from a reference library, allowing instructors to browse and select posture suggestions for learners. This semi-automated feedback loop enhances teaching interactivity and efficiency. Among all evaluated methods, the Transformer model achieved the best accuracy of 92.7% on the dataset, demonstrating the effectiveness of our closed-loop framework in supporting pose classification and model training. The proposed framework contributes both algorithmic insights and a novel application design for posture-driven educational support systems. Full article

The increasing prevalence of sedentary lifestyles poses significant global health challenges, including obesity, diabetes, musculoskeletal disorders, and cardiovascular issues. This paper presents the design and development of a universal smart chair system aimed at mitigating the adverse effects of prolonged sitting. The proposed solution integrates a pressure sensor, vibration motors, an LED strip, and Bluetooth Low-Energy (BLE) communication into a modular and adaptable design. Powered by an STM32WB55CGU6 microcontroller and a rechargeable lithium-ion battery system, the smart chair monitors sitting duration and the user’s posture, and provides alerts through tactile, visual, and auditory notifications. A complementary mobile application allows users to customize sitting time thresholds, monitor activity, and assess battery status. Designed for universal compatibility, the system can be adapted to various chair types. Technical and functional testing demonstrated reliable performance, with the chair operating for over eight workdays on a single charge. The smart chair offers an innovative, cost-effective approach to improving workplace ergonomics and health outcomes, with potential for further enhancements such as posture monitoring. A pilot study with 83 students at VILNIUS TECH showed that the smart chair detected correct posture with 94.78% accuracy, and 97.59% of users responded to alerts by adjusting their posture within an average of 3.27 s. Full article

Background/Objectives: Prolonged sitting is linked to musculoskeletal discomfort, yet optimal sitting posture remains poorly defined, and the consistency with which individuals reproduce specific sitting strategies is unclear. This study examined postural variability across three sitting strategies—comfortable, habitual, and correct—using three common chair types: a stool, computer chair, and ergonomic chair. Methods: Thirty healthy young adults (fifteen men, fifteen women) participated. Global sagittal joint angles—head inclination (HI), trunk angle (TA), and knee angle (KA)—were measured using a motion analysis system across five repetitions per condition. Results: The chair type significantly influenced HI and TA (p < 0.001), with ergonomic chairs encouraging more upright trunk postures. The sitting strategy significantly affected TA and KA (p < 0.01), with comfortable sitting associated with more extended angles. Women exhibited greater TA (114.8° vs. 109.0°, p < 0.001) and lower within-subject variability. Substantial postural variability was observed across all conditions, with mean ranges exceeding minimum detectable change thresholds for HI (10.3°), TA (6.9°), and KA (11.3°). Notably, correct sitting reduced KA variability compared to other strategies (p < 0.01). Conclusions: These findings highlight the individualized and variable nature of sitting posture, even under controlled instructions. The results question the reliability of memory-based seat adjustments and emphasize the need for dynamic, user-centered ergonomic design and personalized clinical guidance to support musculoskeletal health. Full article

Background/Objectives: Non-invasive spinal cord transcutaneous stimulation (scTS) has expanded the therapeutic landscape of spinal cord injury (SCI) rehabilitation, offering potential benefits beyond compensatory approaches to paralysis. Children with SCI are particularly susceptible to developing neuromuscular scoliosis due to trunk muscle paralysis and ongoing skeletal growth, making targeted interventions crucial. As demonstrated in adults and pediatrics with SCI, the ability of scTS to acutely and safely enable an upright posture and trunk control could be leveraged as a therapeutic adjunct. Activity-based locomotor training (AB-LT) alone significantly improves trunk control in children with SCIs; combining it with scTS may enhance outcomes. This pilot study evaluated the safety, feasibility, and cumulative effects of AB-LT combined with scTS on trunk control in children with SCI. Methods: Three children with SCI completed 19 to 64 sessions of combined AB-LT and scTS. Adverse effects were monitored session to session, and trunk control was assessed pre- and post-intervention. Results: Across 130 interventions in three participants, 88.5% of sessions were free from adverse effects. Reported adverse events included autonomic dysreflexia (5.4%), skin redness at electrode sites (4.6%), and headaches (1.5%). No significant impact of scTS on fatigue or central hemodynamic parameters was observed. Post-intervention, all participants demonstrated improved trunk control during quiet and perturbed sitting. Conclusions: These findings provide the first evidence supporting the safety and feasibility of this combinatorial approach in pediatric SCI rehabilitation while emphasizing the importance of monitoring skin integrity and signs of autonomic dysreflexia. This intervention shows potential synergistic benefits, warranting further research to confirm efficacy and optimize therapeutic protocols. Full article

Objectives: Wheelchair seat sagging is hypothesized to increase pressure and shear forces, potentially leading to pressure injuries. The objective of this study was to assess the impact of correcting wheelchair seat sagging on ischial pressure, shear force, and posture in a population of healthy adults. Methods: A total of twenty-two participants who met the study requirements were included in the study. Participants were evaluated under two conditions: with seat base correction (With Correction) and without it (No Correction). Correction was achieved using insert panels. Ischial pressure was measured using a pressure-mapping system (CONFORMat), shear force with a specialized sensor (iShear), and posture with accelerometers (TSND151). The primary analysis compared peak pressure index (PPI), shear force, slide, and postural changes between conditions. The subgroup analysis was conducted as an exploratory approach to assess potential variation among participants with elevated shear forces. Results: There was no statistically significant difference in ischial pressure between the No Correction and With Correction conditions (p = 0.37). However, shear force and slide were significantly reduced when seat sagging was corrected (p < 0.05). Accelerometer data showed no significant difference in postural changes between conditions (p ≥ 0.05), although the With Correction condition displayed a slight trend toward greater positional variability over time. Conclusions: These findings indicate that correcting seat sagging can reduce shear force and slide, potentially lowering the risk of pressure injuries. However, because this study targeted healthy adults, further research involving older or at-risk populations is necessary. Addressing seat sagging could be an important component of comprehensive pressure injury prevention strategies. Full article

Progressive global aging has increased the number of elderly individuals living alone. The consequent rise in fall accidents has worsened physical injuries, reduced the quality of life, and increased medical expenses. Existing wearable fall-detection devices may cause discomfort, and camera-based systems raise privacy concerns. Here, we propose a non-contact fall-detection system that integrates 4D imaging radar sensors with artificial intelligence (AI) technology to detect falls through real-time monitoring and visualization using a web-based dashboard and Unity engine-based avatar, along with immediate alerts. The system eliminates the need for uncomfortable wearable devices and mitigates the privacy issues associated with cameras. The radar sensors generate Point Cloud data (the spatial coordinates, velocity, Doppler power, and time), which allow analysis of the body position and movement. A CNN model classifies postures into standing, sitting, and lying, while changes in the speed and position distinguish falling actions from lying-down actions. The Point Cloud data were normalized and organized using zero padding and k-means clustering to improve the learning efficiency. The model achieved 98.66% accuracy in posture classification and 95% in fall detection. This study demonstrates the effectiveness of the proposed fall detection approach and suggests future directions in multi-sensor integration for indoor applications. Full article

Introduction: Median sternotomy carries post-surgical risks like sternal instability, requiring careful monitoring. Ultrasonography provides a real-time, quantitative assessment of sternal micromovements and has emerged as a promising tool for clinical evaluation. However, its reliability for assessing sternal micromovements post-surgery remains unclear. This study evaluated the inter-rater, intra-rater, and test–retest reliability of ultrasound performed by physiotherapists. Methods: Ultrasound was used to measure the distance between sternal edges in sternotomized patients along the X-axis and Y-axis. Measurements were taken under a resting position, during cough, and in two supine-to-sitting postural transitions (one using a rotational modality and the other with an individual device). Real-time ultrasound imaging acquisition was followed by off-line data elaboration. Assessments were conducted by multiple physiotherapists after a brief training period. Reliability was determined using intraclass correlation coefficients (ICCs), along with the standard error of measurement (SEM) and minimum detectable change (MDC90). ICC values > 0.75 were classified as excellent. Results: A total of 33 subjects with median sternotomy were included (5 women, age 66 ± 7 years). All reliability measurements (24 total) were rated as excellent in each condition examined, with intra-rater ICCs exceeding 0.90, except for on the X-axis during the postural transition using the individual device for supine-to-sitting. SEM values ranged from 0.23 to 0.64 mm, while MDC90 values ranged from 0.54 to 1.50 mm. Conclusions: Ultrasound demonstrated excellent reliability for assessing sternal micromotions when performed by physiotherapists with brief training. Given its reliability, cost-effectiveness, and ease of use, ultrasound sternal micromotions assessment could be integrated into post-surgical rehabilitation to enhance patient care. Full article

Currently, the sedentary nature of office work has led to a steady increase in the prevalence of spinal disorders, including lower back pain, back pain, and neck pain. Medical research has shown that monitoring and improving sitting posture is an important measure to prevent spinal discomfort. The emergence and development of wearable technology have enabled more people to effectively monitor their health. In this study, we propose and design a textile sensor-based sitting posture correction smart garment to realize dynamic sitting reminders aimed at meeting the needs of sedentary office workers. The garment achieves real-time sitting posture recognition through integrated machine learning algorithms, with a recognition accuracy exceeding 95% using a random forest classifier. Additionally, we developed haptic vibration feedback and visual GUI feedback modes to provide sitting posture intervention and dynamic sitting reminders. To evaluate the system’s effectiveness and usability, we conducted comparative experiments analyzing sitting posture behavior before and after wearing the smart garment, along with a user satisfaction survey. The results demonstrate that the smart garment effectively helps office workers adjust their sitting posture and reduces the risk of spinal discomfort associated with prolonged sedentary work. Full article

Background: Aging is associated with musculoskeletal pain and postural adaptations which may affect functionality. This study aims to analyse the effect of a combined protocol of self-assisted manual therapy and high-intensity walking on musculoskeletal back pain, functionality, and shoulder posture in older adults, and to establish the short- and medium-term effects of this program. Methods: A multicentre, double-blind, randomized trial was conducted on older adults. The sample was divided into two groups: the self-assisted manual therapy plus walking at high-intensity group (MTWG) and the Control Group (CG), with the latter undergoing supervised high-intensity walking only. Pain (Pressure Pain Threshold and Visual Analogue Scale), functional capacity (5-times sit-to-stand test), and change in thorax position (acromion position) were assessed at T0 (baseline), T1 (after 4-week intervention) and T2 (follow-up, 4 weeks after the end of the intervention). Results: A total of 95 older adults (41 in the MTWG and 54 in CG) completed the study and were analyzed. After isolating the effect of correlations among our primary outcomes, our analysis revealed statistically significant between-subject (p < 0.01), within-subject (p < 0.001) and between-within subject differences (p < 0.05) in Pressure Pain Threshold scores in favour of the MTWG. We also detected within-subjects (p < 0.001) and between-within subject differences (p < 0.05) in scores for the Visual Analogue Scale, in favour of the MTWG. These patterns of results remained stable at T2. The 5-times sit-to-stand test (p < 0.01) and the acromion position (p < 0.05) improved at T1 for the MTWG but not at T2. Conclusions: A combined protocol of self-assisted manual therapy and high-intensity walking, compared to high-intensity walking alone, improved musculoskeletal pain, functionality, and posture in older adults in the short term (over one month), with pain reduction maintained in the medium term (at the one-month follow-up). Full article

To address lower limb fatigue in workers engaged in prolonged standing, this study proposes a structural design for a medial-support passive exoskeleton seat. The design incorporates support rods positioned along the medial aspect of the user’s lower limbs and features an adaptive telescopic rod system, enhancing sitting stability and reducing collision risks in workplace environments. Human motion capture technology was used to collect kinematic data of the lower limbs, and a mathematical model of center-of-gravity variation was developed to calculate and optimize the exoskeleton’s structural parameters. Static analysis was performed using ANSYS software (2025 R1) to evaluate the structural integrity of the design. The effectiveness of the exoskeleton seat was validated through surface electromyography (sEMG) experiments, with results showing that the exoskeleton significantly reduces lower limb muscle load by 49.2% to 72.9%. Additionally, force plate experiments demonstrated that the exoskeleton seat improves stability, with a 39.2% reduction in the average displacement of the center of pressure (CoP), confirming its superior postural alignment and balance. The design was also compared with existing exoskeleton chairs, showing comparable or better performance in terms of muscle load reduction, stability, and overall effectiveness. Full article

Background/Objectives: Sedentary office workers (SOWs) often adopt prolonged sitting postures, which potentially disrupt the lumbar–pelvic rhythm (LPR) and contribute to lower back pain (LBP). This study aimed to clarify the group differences in LPR and related physical factors between SOWs with and without LBP. Methods: Sixty-three SOWs were divided into LBP (n = 30) and non-LBP (n = 33) groups. The lumbar flexion angle (LF) and lumbar–hip angle difference (LHD), which are indicators of LPR, were measured using inertial sensors during trunk flexion. Hip flexion muscle strength (HFMS) and hip-extension muscle strength (HEMS) were assessed using handheld dynamometry. Hip joint range of motion (ROM) was measured using a goniometer. Lumbar proprioception was evaluated via active joint repositioning, and pain and perception were assessed using the Visual Analog Scale, Oswestry Disability Index, and Fremantle Back Awareness Questionnaire. Results: Multiple regression analysis showed significantly greater LF (estimated regression coefficient [ERC]: −2.9, p < 0.05) and LHD (ERC: −5.5, p < 0.05) during early trunk flexion (ETF) in the LBP group. In the LBP group, LHD during ETF and late trunk flexion were positively correlated with HFMS, and HFMS was correlated with HEMS. Conclusions: HFMS may contribute to an altered LPR in SOWs with LBP. Full article