Search Results (622)

To enable the practical application of passive back-support exoskeletons employing pneumatic artificial muscles (PAMs) in tasks such as agricultural work, we evaluated their assistive effectiveness in a half-squatting posture with a staggered stance. In this context, assistive force profiles were adjusted according to body posture to achieve more effective support. The targeted assistive force profile was designed to be continuously active from the standing to the half-squatting position, with minimal variation across this range. The assistive force profile was developed based on a PAM contractile force model and implemented using a cam mechanism. The effectiveness of assistance was assessed by measuring body flexion angles and erector spinae muscle activity during lifting and carrying tasks. The results showed that the assistive effect was greater on the side with the forward leg. Compared to the condition without exoskeleton assistance, the conventional pulley-based system reduced muscle activity by approximately 20% whereas the cam-based system achieved a reduction of approximately 30%. 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

Falls are a major safety concern in physically demanding occupations such as roofing, where workers operate on inclined surfaces under unstable postures. While inertial measurement units (IMUs) are widely used in wearable fall detection systems, they often fail to capture early indicators of instability related to foot–ground interactions. This study evaluates the effectiveness of plantar pressure sensors, alone and combined with IMUs, for fall detection on sloped surfaces. We collected data in a controlled laboratory environment using a custom-built roof mockup with incline angles of 0°, 15°, and 30°. Participants performed roofing-relevant activities, including standing, walking, stooping, kneeling, and simulated fall events. Statistical features were extracted from synchronized IMU and plantar pressure data, and multiple machine learning models were trained and evaluated, including traditional classifiers and deep learning architectures, such as MLP and CNN. Our results show that integrating plantar pressure sensors significantly improves fall detection. A CNN using just three IMUs and two plantar pressure sensors achieved the highest F1 score of 0.88, outperforming the full 17-sensor IMU setup. These findings support the use of multimodal sensor fusion for developing efficient and accurate wearable systems for fall detection and physical health monitoring. Full article

The present study aims to investigate the multi-year effects (5 years) of individualized whole-body vibration (WBV) on locomotion, postural control, and handgrip strength in a 68-year-old man with relapse remitting multiple sclerosis (PwRRMS). The dose–response relationship induced by a single session was quantified by determining the surface electromyographic activity (sEMG) of the participant. The participant wore an orthosis to limit the lack of foot dorsiflexion in the weakest limb during walking in daily life. The gait alteration during walking was assessed at 1, 2 and 3 km/h (without the orthosis) through angle–angle diagrams by quantifying the area, perimeter and shape of the loops, and the sEMG of leg muscles was recorded in both limbs. The evaluation of postural control was conducted during upright standing by quantifying the displacement of the center of pressure (CoP). The handgrip strength was assessed by measuring the force–time profile synchronized with the sEMG activity of upper arm muscles. The participant improved his ability to walk at higher speeds (2–3 km/h) without the orthosis. There were greater improvements in the area and perimeter of angle–angle diagrams for the weakest limb (Δ = 36–51%). The sEMG activity of the shank muscles increased at all speeds, particularly in the tibialis anterior of weakest limbs (Δ = 10–68%). The CoP displacement during upright standing decreased (Δ = 40–60%), whereas the handgrip strength increased (Δ = 32% average). Over the 5-year period of intervention, the individualized WBV improved locomotion, postural control and handgrip strength without side effects. Future studies should consider the possibility of implementing an individualized WBV in PwRRMS. 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

(1) Background: The paper focuses on foot biomechanics in static situations. The aim was to determine the distribution of the load exerted by the human body on the ground in order to establish reference points on the foot for correct human body posture. (2) Methods: A model was developed to describe the body weight-ground relationship, consisting of a support platform and a part imitating the rest of the human body. Experiments consisted of tilting the general centre of gravity from the maximum forward through midfoot, a passive, neutral position, to the maximum backwards while maintaining balance. The ground load was measured in each position. (3) Results: The loads of the front and rear parts of the support platform and the resultant load force at different degrees of body tilt were calculated. It has been shown that at the maximum inclination of the body to the extreme support point, the entire weight falls on this point. For the neutral position (in the Basic Balance Point), the load on the front and rear parts of the support platform was 26% and 74%, and 40% and 60% for the passive position (in the Passive Balance Point). (4) Conclusions: The distribution of body weight on the ground is determined by the projection of the general centre of gravity on the ground through the feet. The resultant ground reaction force defines both the magnitude and direction of the load exerted on the support platform. Ground reaction forces associated with body weight were assessed at five anatomical points of the foot: the forefoot, rearfoot, midfoot, and the Passive and Basic Balance Point. In an upright standing posture, the projection of the general centre of gravity fluctuates between the Passive and Basic Balance Point, corresponding to the passive and neutral positions, respectively. Only in the neutral position, the body’s weight, as concentrated in the general centre of gravity, falls on the axis of the upper ankle joint and distributes the load between the forefoot and rearfoot. Determining the correct distribution of foot loads may serve in the future to study abnormalities in human body posture Full article

Background/Objectives: Spasticity in children with cerebral palsy (CP) can impair motor-related functions. The objective of this exploratory, prospective study was to examine if transcutaneous electrical nerve stimulation (TENS) in a whole-body suit leads to changes in spasticity and other related effects. Methods: Thirty-one children with CP GMFCS III–V, with a median age of 11.0 years (age range of 7–17 years), were consecutively included, and they used the suit with TENS for 24 weeks. The primary outcome was spasticity measured using the Modified Ashworth Scale (MAS). Functional motor-related tasks were evaluated by the Goal Attainment Scale (SMART GAS). The Modified Tardieu Scale (MTS), passive Range of Motion (pROM), GMFM-66, and Posture and Postural Ability Scale (PPAS) assessments were performed. Results: Seventeen subjects (17/31) completed the 24 weeks. Dropout was due to difficulty in donning the suit. The level of overall spasticity, most pronounced in the proximal arms and legs, was reduced according to the MAS, but not the MTS or pROM. Subject-relevant motor-related goals improved significantly in standing/walking and hand/arm function. Changes in the GMFM-66 and PPAS were not significant. Conclusions: Although there were statistically significant but underpowered changes in the MAS after 24 weeks, there were no clinically relevant effects. Exploratorily, we found observer-reliant motor-related functional improvements, which, however, we were unable to detect when trying to quantify them. Donning the suit led to dropout throughout the study. Caregivers need to allocate time, mental capacity and have the physical skill set for donning the suit for long-term use. Full article

Background: The vestibular Romberg test, which assesses the deterioration of balance while standing on rubber foam with closed eyes, is a well-established method in the physical neurological assessment of patients with peripheral vestibulopathy. This study aims to determine whether it can differentiate peripheral vestibulopathy from its main differential diagnosis, namely sensory ataxia, as both conditions typically present with a positive classical Romberg test. Methods: Static balance was assessed in three groups: patients with peripheral vestibulopathy, patients with pure sensory neuropathy, and healthy age-matched controls. Participants stood quietly on a force platform under varying visual and proprioceptive feedback conditions. Conventional and advanced postural sway metrics were investigated to establish a quantitative analogy to both the clinical Romberg and vestibular Romberg tests. Results: Posturographic analysis revealed that, in contrast to healthy controls, patients with vestibular disorders exhibited higher vestibular Romberg quotient values. However, the classical vestibular Romberg quotient did not show diagnostic discrimination between vestibulopathy and sensory neuropathy patients. This lack of discrimination was mainly due to the increased body sway observed in all patient groups under the “eyes open” condition. Nevertheless, a refined vestibular Romberg quotient—comparing standing on foam versus standing on firm support with eyes closed—was able to reliably distinguish vestibulopathy from sensory ataxia. This distinction was evident in both conventional linear sway and spectral postural sway metrics. Conclusions: We conclude that a refined Romberg test, performed solely under conditions of visual deprivation, offers valuable classification potential in differentiating peripheral vestibulopathy not only from healthy controls but also from patients with disequilibrium due to sensory loss. Full article

Sedentary behavior at work is a major, and growing, public health concern. This field experiment investigates the effectiveness of behavioral nudges, specifically default settings on height-adjustable workstations (HAWS), in promoting stand-up working behavior. It also examines whether transparency and health coaching enhance these effects. The study was conducted in a Belgian governmental organization and included 149 employees across eight departments. Departments were randomly assigned to one of four conditions: a non-transparent default nudge (NTDN), a transparent default nudge (TDN), a classical health coaching intervention, or a hybrid intervention combining TDN and coaching. Over an eight-week intervention period, employee posture was recorded using fixed camera snapshots taken every 30 min. These data were used to calculate the stand-up ratio. The NTDN increased stand-up rates from 1.82% to 4.93%. The TDN more than doubled this effect, reaching 11.25%. The combination of TDN and coaching produced the highest increase, with stand-up rates rising to 18.80% (d = 9.85). Coaching alone showed no significant effect. Although behavior partially regressed after the interventions were removed, post-measurement stand-up ratios after a week remained higher than baseline. These findings suggest that transparent default nudges, especially when combined with low-threshold coaching, can meaningfully reduce sedentary behavior in everyday office environments. Full article

Background: This study compared performance-based function and self-report function in lower-limb prosthesis users. Methods: Twenty-two lower-limb prosthesis users (aged 52.1 ± 14.2) were administered the Orthotic Prosthetic User Survey (OPUS) Lower Extremity Functional Status (LEF), Satisfaction With Devices (SWD), alongside the Godin Leisure-Time Exercise Questionnaire (GLTQ), Timed Up and Go (TUG) test, two-minute walk test (2MWT), and six-minute walk test (6MWT). Body composition and standing postural sway displacement and velocity were also measured. Pearson’s Product Moment coefficients were used to assess relationships between the OPUS and other outcome variables. ANOVAs were used to identify differences in all outcome variables between lower unilateral (LU) and all other (AO) amputees. Results: There was a moderate correlation between LEF and center of pressure (CoP) path length with eyes open (r₍₁₉₎ = −0.43, p = 0.048) and eyes closed (r₍₁₉₎ = −0.43, p = 0.049). While the relationship between LEF and TUG was significant (r₍₂₀₎ = −0.49, p = 0.021), this was not so with SWD and TUG (r₍₂₀₎ = −0.17, p = 0.456). Both the 2MWT (r₍₂₀₎ = 0.48, p = 0.023) and 6MWT (r₍₂₀₎ = 0.47, p = 0.028) were moderately correlated with LEF. GLTQ was significantly correlated with LEF (r₍₂₀₎ = 0.70, p = 0.001). The LU group outperformed the AP group during the TUG and 6MWT (p < 0.05). LU group scored significantly higher on LEF compared to the AO group (p < 0.05). The reliability of LEF between the measurement on day 1 (54.3 ± 12.0) and day 2 (53.6 ± 12.8) was high (α = 0.94). Conclusions: This study provides an insight into associations of balance and self-reported function in lower limb prosthesis users. Future work can target rehabilitation strategies to address challenges faced by multiple limb prosthesis users. Full article

The purpose of this study was to determine the effect of static stretching (SS) duration on balance. Twenty-two participants performed passive dorsiflexion measurements and balance tests before and after SS. Passive dorsiflexion measurements determined the maximal dorsiflexion angle, passive torque, displacement of the muscle–tendon junction, and electromyography amplitude during passive dorsiflexion. In the balance test, the participant stood on a single leg with their eyes open while the postural sway evaluated in the center of pressure (COP), standing duration, and electromyography amplitude were measured. The ankle and metatarsophalangeal joints underwent SS for 30 s × one set, two sets, and four sets. There were significant increases in COP displacement and COP velocity after two sets of SS but not after one and four sets. Standing duration and electromyography during balance tests were not changed after SS. No gender differences were found in changes in balance. Maximal dorsiflexion angle and passive torque were increased after SS, but the displacement of the muscle–tendon junction and electromyography during passive dorsiflexion were not changed. There was no significant correlation between changes in maximal dorsiflexion angle or passive torque and changes in COP variables after two sets of SS. These results therefore revealed that SS duration affects COP displacement and COP velocity. Full article

Physiotherapy aims to improve postural dysfunction, often using balance exercises. The effects of rehabilitation-based balance exercises on postural control in dogs remains understudied. This study aimed to assess the impact of specific balancing exercises and blindfolding on center of pressure parameters in healthy dogs. Thirteen healthy adult dogs participated in the study. Center of pressure parameters were measured using a pressure platform during quiet standing, external perturbation, head turn, and blindfolded trials. External perturbation significantly increased the area of the elliptical sway, cranio-caudal excursion, and right–left excursion. Head turning led to large effect sizes, but no significant differences compared to quiet standing. Blindfolding led to medium to large effect sizes, though no significant differences were observed. The study confirmed that external perturbation challenges postural stability, resulting in increased sway. Head turning induces sway but may require further training or different methodologies for reliable outcomes. Blindfolding increased sway but was not statistically different. These findings underscore the potential use of perturbation-based exercises in canine rehabilitation to improve balance, while also highlighting the need for further studies to standardize balance challenges and explore the effects in dogs with orthopedic or neurological conditions. Full article

Aim: The aim of this study was to evaluate the specificity, sensitivity and accuracy of the Indicator Plaster Neuropad in detecting established Diabetic Autonomic Neuropathy (DAN). Methods: We studied 180 patients with Diabetes Mellitus (DM, mean age 49.5 ± 16 years, 82 with DM type 1). All patients underwent the following Cardiovascular Reflex Tests (CARTs): R-R variation during deep breathing (Mean Circular Resultant (MCR) and standard deviation (SD)), Valsalva maneuver, R-R variability after a rapid change from lying to standing position and postural hypotension. The presence of DAN was established if ≥2 CARTs were abnormal. According to the result the patients were divided into two groups, one with DAN and one without DAN. Assessment with Neuropad was performed also in all patients. Results: Abnormal perspiration with Neuropad (uncompleted or no change in color) was detected in 94 patients. Established DAN was detected in 85 patients. The sensitivity, specificity and accuracy of Neuropad for the diagnosis of established DAN were 87.1%, 78.9% and 82.8%, respectively and area under the curve was 0.846 and 95% CI (0.787, 0.905). Conclusions: Neuropad has high sensitivity, specificity, and accuracy in detecting established DAN, as defined by ≥2 abnormal CARTs. Full article

The aim of the study was to verify the relationship between musculoskeletal pain of elite Polish goalball players and selected physique and posture characteristics. We examined 12 players. The mean age was 21.8 ± 6.0 years, and a mean training experience of 6.3 ± 3.4 years. Physique (body mass, body height, waist circumference, fat tissue, fat-free soft tissue) and posture (thoracic kyphosis and lumbar lordosis) and range of motion (in the thoracic and lumbar regions) were assessed. The incidences and locations of musculoskeletal pain were identified using the Nordic Musculoskeletal Questionnaire, covering the period from the last seven days (NMQ-7) and six months (NMQ-6). Due to the small group size, non-parametric tests (Spearman’s rank correlation) were used. The significance level was set at p < 0.05. Players were more likely to report musculoskeletal pain in the last six months than in the previous week. Pain reported in both NMQ6 and NMQ7 was most common in the wrists/hands and lower back, and, in NMQ6, also in the shoulders and ankles/feet. There were significant negative correlations of total NMQ7 with lumbar lordosis angle in the habitual standing position (R = −0.6; p = 0.04), trunk flexion (R = −0.8, p = 0.002), and trunk extension (R = −0.6; p = 0.03), and a positive correlation with thoracic kyphosis angle in trunk flexion (R = 0.8, p = 0.005). There was a statistically significant, inversely proportional relationship of thoracic kyphosis angle values in the habitual position (R = −0.58; p = 0.049) and thoracic kyphosis angle THA in trunk flexion (R = −0.6; p = 0.038) with time of disability. Relationships between some body posture parameters and musculoskeletal pain in the studied athletes were also noted. Full article