Bending Position Research Articles

Analysis and improvement of human stability in floodwaters through numerical simulation with SPH-DEM model

This study improves the formulae for determining the incipient velocity of sliding and toppling instability through force analysis. It introduces a self-adjusting posture parameter to make the approach applicable to actual human subjects. In addition, a novel concept of critical water depth is proposed to classify the type of instability. The smoothed particle hydrodynamics model, coupled with the discrete element method, is employed to simulate the instability scenarios of human bodies. Through the validated fluid–structure interaction model, the influence of critical factors on human stability is investigated, including the friction coefficient, height, mass, and body postures. The developed formulae are corroborated with experimental data about actual human subjects. The incipient velocity formula for toppling instability in a bending posture is introduced, previously overlooked in the literature. The results contribute new insights into the instability criterion for individuals in floodwaters and offer additional strategies to enhance human stability.

Can Surgery Be Proposed to Adolescent Idiopathic Scoliosis Patients With Structural Lumbar Curves Associated With Nonreducible Iliolumbar Angle?

Lower instrumented vertebra (LIV) selection for adolescent idiopathic scoliosis (AIS) with structural lumbar curves (Lenke 3, 5, and 6) remains debated. The iliolumbar angle (ILA) measurement is useful for assessing the lumbosacral junction flexibility. If it is nonreducible, surgeons need to make a difficult choice between a potential "imperfect" L4, associated with a residual lumbosacral curve, or a more distal fusion performed later in life due to poorer functional outcomes. The goal of this study was, therefore, to evaluate the postoperative radiographic and functional outcomes of AIS patients with nonreducible ILA. All consecutive AIS patients (2017 to 2022) with a structural lumbar curve and a posterior fusion ending on L4 were retrospectively included. Radiographic and functional outcomes (SRS-30 score) were reported with a minimum 2-year follow-up. Standing low dose stereoradiographs in both erect and maximum lateral bending positions were performed in all patients, and 2 groups of subjects were compared based on preoperative ILA flexibility [reducible group (R) or nonreducible group (NR)]. A total of 122 patients were included (30% NR and 71% R). At a mean follow-up of 2.3±0.1 years, surgery was efficient in correcting the major curve (77% reduction rate in the R group and 76% in the NR group, P<10-5), and significantly improved coronal balance (R, P<10-5 and NR, P=0.03) as well as the ILA [mean ILA gain 14 degrees (R group), P<10-5 and 16 degrees (NR group), P<10-5]. The proportion of excellent results was higher in the R group, but 97% of outcomes were either excellent or acceptable in the NR group, and only 1 case of poor result (residual ILA >10 degrees) was reported in each group. No significant difference was found in SRS 30 scores between groups, but scores were significantly improved in the NR group for the excellent outcomes' subgroup [self-image (P=0.04) and satisfaction (P=0.02) domains]. The current study confirms that posterior fusion ending on L4 can still be proposed to young AIS patients with structural lumbar curves, even if the lumbosacral flexibility is limited. Level III-comparative study.

Design and Validation of a Biomimetic Leg-Claw Mechanism Capable of Perching and Grasping for Multirotor Drones.

Multirotor drones are widely used in fields such as environmental monitoring, agricultural inspection, and package delivery, but they still face numerous challenges in durability and aerial operation capabilities. To address these issues, this paper presents a biomimetic leg-claw mechanism (LCM) inspired by the biomechanics of birds. The claw of the LCM adopts a bistable gripper design that can rapidly close through external impact or actively close via the coordination of internal mechanisms. Additionally, its foldable, parallelogram-shaped legs bend under external forces, stretching the main tendon. A ratchet and pawl mechanism at the knee joint locks the leg in the bent position, thereby enhancing the gripping force of the claw. This paper calculates and experimentally verifies the degrees of freedom in different states, the forces required to open and close the gripper, the application scenarios of active and passive grasping, and the maximum load capacity of the mechanism. Furthermore, perching experiments demonstrate that the LCM enables the drone to perch stably on objects of varying diameters.

Factors Associated with Musculoskeletal Disorders Among Cleaners in a Nigerian University

Background: Musculoskeletal disorders (MSDs) remain a significant public health concern worldwide, particularly among cleaning personnel, due to their physically demanding tasks and often strenuous work conditions. Objective: To assess the factors associated with work-related MSDs among cleaners in a public university. Methods: A cross-sectional study of 320 informal cleaning staff employed on contract in Obafemi Awolowo University, Ile-Ife, Nigeria, was conducted. A semi-structured questionnaire with questions adapted from the Nordic musculoskeletal questionnaire was used to obtain information on socio-demographics, work practices and prevalence/sites of MSD. Results: The majority (190; 59.4%) of respondents were aged 40-60 years, and most (298; 93.1%) were females. Most respondents (280; 87.5%) earned &lt; N19,000= $50 monthly, and 247 (77.2%) had worked for ≤10 years. A majority (88.1%) worked 6-8 hours daily, with 99.1% working in a bent position and 83.4% standing for &gt;2 hours at a time. In the preceding 7 days, the MSD prevalence was 58.2%, while the common MSD-affected sites were the lower back (35.9%), knees (23.1%), hips/thighs (15.9%), and right shoulder (15.6%). The predictors of MSDs included age &gt;50 years, having no formal education, lack of prior safety training and being overweight/obese. Conclusion: The study highlighted a significant MSD burden among cleaning staff, primarily affecting the lower back, knees and thighs. It is recommended that employers implement ergonomics and safety training, improved welfare packages, and regular health screenings to reduce MSD burden and promote cleaners' well-being.

Impact of postural variations on trunk rotation angle during the forward bending test in adolescents idiopathic scoliosis.

To evaluate the impact of different positions of adolescent idiopathic scoliosis (AIS) patients and examiners on the angle of trunk rotation (ATR) measured during the forward bending test (FBT) with Scoliometer. Adolescents who had come to the hospital for outpatient were recruited. Considering the location of the subject and the examiner, four postural combinations of ATR were measured. After measuring ATR, the subject underwent radiographic measurements for diagnosis of AIS. Mann-Whitney test was used for the inter-group reliability test in two examiners, and the Kruskal-Wallis test was used to measure intra-group differences in ATR for the four positions. The receiver operating characteristic curve and area under the curve were used to evaluate the diagnostic performance of ATR in AIS measured by different postures. Preplanned sensitivity analyses of the primary outcome were performed by subgroup. Of the 63 participants suspected of having AIS included, there was no statistically significant difference (P > 0.05) observed between ATR measurements taken in different postures. Only the measurements taken by the examiner from behind the subject demonstrated diagnostic capability for AIS (AUC = 0.73 for both feet together and apart, ). There was no statistically significant difference ( in diagnostic ability between the subjects who stood with feet together or apart. The sensitivity analysis supports the robustness of the conclusions ( . When the examiner measured from behind the subject, AIS can be effectively diagnosed, regardless of whether the subject is standing on feet apart or feet together. There is no difference in diagnostic ability in ATR between the two forward bending positions. Level III.

Development of a gender-specific European job exposure matrix (EuroJEM) for physical workload and its validation against musculoskeletal pain.

The aim was to develop a gender-specific European job exposure matrix (EuroJEM) for occupational physical workload and study its predictive validity for musculoskeletal pain in four European cohorts. National, gender-specific JEM from Finland, France, Norway and Sweden, based on self-reported exposure information, were evaluated for similarities in exposures, exposure definitions, and occupational coding. The EuroJEM harmonized five exposures: heavy lifting, faster breathing due to heavy workload, kneeling/squatting, forward bent posture, and working with hands above shoulder level. Our expert panel addressed disagreements and missing information to reach consensus on exposure levels across occupations. To assess predictive validity of the EuroJEM, we examined associations between the harmonized exposure measures and self-reported musculoskeletal pain across the four cohorts. The EuroJEM provides semi-quantitative exposure estimates for 374 ISCO-88 (COM) occupational codes. Five categories of exposure were defined by the proportion of workers exposed within each occupation. Comparable and statistically significant associations were found between EuroJEM exposures and low back, shoulder, and knee pain across all cohorts and genders, except for knee pain among women in the Finnish cohort. For instance, in both genders heavy lifting, faster breathing due to heavy workload, and forward bent posture were statistically significantly associated with low-back pain in all four cohorts, with OR ranging from 1.25-2.18 (men) and 1.23-2.04 (women). Despite differences in study populations and outcome definitions, good predictive validity was observed in each national cohort, suggesting that EuroJEM can be an effective tool for exposure assessment in large-scale European epidemiological studies.

Mobile device-based 3D scanning is superior to scoliometer in assessment of adolescent idiopathic scoliosis.

Screening for adolescent idiopathic scoliosis (AIS) currently relies on clinical evaluations by trained practitioners, most commonly using a scoliometer. Modern structured light 3D scanning can generate high-quality 3D representations of surface anatomy using a mobile device. We hypothesized that a mobile-based 3D scanning system would provide accurate deformity assessments compared to a scoliometer. Between August 2020 and June 2022, patients 10-18 years being evaluated for AIS in our clinic with a scoliosis radiograph obtained within 30 days of clinic evaluation and no history of spinal surgery were enrolled. Patients had 3D scans taken in the upright and forward bend positions, and the largest angle of trunk rotation (ATR) was measured by a scoliometer. Image processing software was used to analyze trunk shift (TS), coronal balance (CB), and clavicle angle (CL) in the upright position and the largest ATR in the forward bend position. 3D and scoliometer measurements were correlated to major curve magnitude. Multiple logistic regression models were created based on 3D and scoliometer measurements, controlling for demographic covariates. Two hundred and fifty-eight patients were included in this study. Mean coronal major curve magnitude was 25.7° (range 0-100), and 59% had a thoracic major curve. There were good-to-excellent correlations between 3D and radiographic measures of TS, CB, and CL (r = 0.79, rs = 0.80, and r = 0.64, respectively, p < 0.001). Correlations between 3D and radiographic measures of largest lumbar and thoracic ATR also demonstrated good correlations (r = 0.64 for both, p < 0.001). Using Akaike's Information Criterion (AIC), a multivariable logistic regression model based on 3D scanning outperformed a scoliometer model. Mobile device-based 3D scanning of TS, CB, and TS identifies clinically relevant scoliotic deformity and is more predictive of radiographic curve magnitude than scoliometer in this population. This new modality may facilitate scoliosis screening by decreasing the need for trained personnel or dedicated equipment and clinical space to perform screening tests. II.

Failure and optimization of composite-to-steel adhesive bonded Y-joints under three-point bending

This paper aims to investigate damage behavior and failure mechanism of adhesive-bonded Y-joints consisting of carbon fiber-reinforced polymer (CFRP) skins, PVC cores, and steel plates under three-point bending loading. Five three-point bending tests are adopted to study the load-bearing characteristic and damage mode of joint under different skin thicknesses and bending positions. Meanwhile, a procedure is developed to characterize the composite material failure by user-defined subroutine VUMAT, and numerical simulation is performed to reveal the flexural behavior and failure mechanism. Subsequently, structural optimization of the Y-joint is carried out in conjunction with ABAQUS-Isight, considering the thickness and lap length of CFRP skins. Reasonably good agreement is achieved when comparing the flexural behavior between experimental results and numerical predictions. These studies reveal that the bending load capacity of the Y-joint exhibits an increase with greater plate thickness, and the damage of plates and core is more serious when the bending location is near the core. Furthermore, the load-bearing capacity of Y-joint increases by 20.4% when the number of CFRP layers is 7 while the overlap lengths are 140 mm and 85 mm, respectively. This finding indicates that the optimized joint achieves a higher load-bearing capacity with a minor increase in mass.

Redesign of stroller work tools at PT. Ika Bina Agro Wisesa

PT. Ika Bina Agro Wisesa (PT. IBAS) is one of the agro-industries that manages or produces palm oil with a production capacity of 30 tons / hour and a total of 420 tons / day. The raw material of Fresh Fruit Bunches (FFB) of this factory comes from the plantation land of the community around the factory. The activity of harvesting FFB in this oil palm plantation has many manual material handling activities, especially for workers who lift and push wheelbarrows (angkong). The angkong work tool used is relatively old and looks unergonomic which can be seen when pushing the angkong in a very bent position so it is assumed that there is a large amount of force expended by workers. This research begins with a survey of the company and the field, then distributing Nordic Body Map (NBM) questionnaires to workers, using the Rapid Entire Body Assessment (REBA) method used to determine the level of risk of work posture in workers before and after the design of the tool, for the redesign of the stroller, anthropometric measurements are taken then using the Biomechanics method to determine the amount of force generated when pushing. This stroller redesign was carried out using operator anthropometry with the 95th percentile. After using the proposed tool, the work posture assessment is categorized as moderate which means that action is needed. The final results of the redesign are the length of the cart 90 cm, the width of the cart 66 cm, the diameter of the tire 32 cm, the height of the cart from the ground 125 cm, the height of the handle 96 cm, the width of the handle 40 cm, and the diameter of the handle 3 cm and the final results of the biomechanical assessment after the design concluded that the operator was no longer dangerous when pushing.

Understanding gait alterations: trunk flexion and its effects on walking neuromechanics.

Evolutionary and functional adaptations of morphology and postural tone of the spine and trunk are intrinsically shaped by the field of gravity in which humans move. Gravity also significantly impacts the timing and levels of neuromuscular activation, particularly in foot-support interactions. During step-to-step transitions, the centre of mass velocity must be redirected from downwards to upwards. When walking upright, this redirection is initiated by the trailing leg, propelling the body forward and upward before foot contact of the leading leg, defined as an anticipated transition. In this study, we investigated the neuromechanical adjustments when walking with a bent posture. Twenty adults walked on an instrumented treadmill at 4 km h-1 under normal (upright) conditions and with varying degrees of anterior trunk flexion (10, 20, 30 and 40deg). We recorded lower-limb kinematics, ground reaction forces under each foot, and the electromyography activity of five lower-limb muscles. Our findings indicate that with increasing trunk flexion, there is a lack of these anticipatory step-to-step transitions, and the leading limb performs the redirection after the ground collision. Surprisingly, attenuating distal extensor muscle activity at the end of stance is one of the main impacts of trunk flexion. Our observations may help us to understand the physiological mechanisms and biomechanical regulations underlying our tendency towards an upright posture, as well as possible motor control disturbances in some diseases associated with trunk orientation problems.

Segmental vertebral three-dimensional motion in patients with L4 isthmic spondylolisthesis under weight-bearing conditions

ObjectiveTo investigate in vivo 6-degree-of-freedom (DOF) vertebral motion in patients with isthmic spondylolisthesis (IS) during various functional weight-bearing activities.MethodsFifteen asymptomatic volunteers (mean age 54.8 years) and fourteen patients with IS at L4-5 (mean age 53.4 years) were recruited. The positions of the vertebrae (L4-L5) in the supine, standing, flexion–extension, left–right twisting and left–right bending positions were determined using previously described CT-based models and dual fluoroscopic imaging techniques. Local coordinate systems were established at the center of the anterior vertebra of L4 isthmic spondylolisthesis (AIS), the posterior lamina of L4 isthmic spondylolisthesis (PIS) and the center of the L5 vertebra to obtain the 6DOF range of motion (ROM) at L4-L5 and the range of motion (ROM) between the AIS and the PIS.ResultsThe translation along the anteroposterior axis at L4-L5 during flexion–extension, left–right bending and left–right twisting was significantly greater than that of the healthy participants. However, the translation along the mediolateral axis at L4-L5 presented paradoxical motion under different positions: the ROM increased in the supine-standing and flexion–extension positions but decreased in the left–right bending and left–right twisting positions. The separation along the anteroposterior axis during flexion was significantly greater than that during standing, on average, reaching more than 1 mm. The separation along the mediolateral axis during standing, flexion and extension was significantly greater than that in the supine position.ConclusionsThis study revealed the occurrence of displacement between the AIS and PIS, primarily in the form of separation during flexion. Symptomatic patients with isthmic spondylolisthesis exhibit intervertebral instability, which might be underestimated by flexion–extension radiographs.

Artificial Intelligence Measurement of Preoperative Radiographs in Adolescent Idiopathic Scoliosis Based on Multiple-View Semantic Segmentation.

Cross-sectional study. Imaging classification of adolescent idiopathic scoliosis (AIS) is directly related to the surgical strategy, but the artificial classification is complex and depends on doctors' experience. This study investigated deep learning-based automated classification methods (DL group) for AIS and validated the consistency of machine classification and manual classification (M group). A total of 506 cases (81 males and 425 females) and 1812 AIS full spine images in the anteroposterior (AP), lateral (LAT), left bending (LB) and right bending (RB) positions were retrospectively used for training. The mean age was 13.6 ± 1.8. The mean maximum Cobb angle was 46.8 ± 12.0. U-Net semantic segmentation neural network technology and deep learning methods were used to automatically segment and establish the alignment relationship between multiple views of the spine, and to extract spinal features such as the Cobb angle. The type of each test case was automatically calculated according to Lenke's rule. An additional 107 cases of adolescent idiopathic scoliosis imaging were prospectively used for testing. The consistency of the DL group and M group was compared. Automatic vertebral body segmentation and recognition, multi-view alignment of the spine and automatic Cobb angle measurement were implemented. Compare to the M group, the consistency of the DL group was significantly higher in 3 aspects: type of lateral convexity (0.989 vs 0.566), lumbar curvature modifier (0.932 vs 0.738), and sagittal plane modifier (0.987 vs 0.522). Deep learning enables automated Cobb angle measurement and automated Lenke classification of idiopathic scoliosis whole spine radiographs with higher consistency than manual measurement classification.

Repeatability and intra and interrater reproducibility of the DIPA-S eHealth© capture and analysis system for clinical assessment of scoliosis.

To assess the repeatability, intra and interrater reproducibility of the DIPA-S eHealth© system for capturing and measuring clinical variables of scoliosis, including frontal trunk imbalance (FTI), sagittal trunk imbalance (STI), and angle of trunk rotation (ATR). Patients were photographed using the DIPA-S eHealth Capture© mobile application by family members, physiotherapists, or surgeons. Three photos were taken in each position: standing in the frontal and sagittal planes and in the axial plane in forward bending position of the trunk. The photos were analyzed by three independent evaluators using the DIPA-S eHealth Analysis© software. For repeatability, each photo was analyzed twice consecutively by the three evaluators. For intrarater reproducibility, only one evaluator reanalyzed the first photo from each plane with a 5-day interval. For interrater reproducibility, the three evaluators analyzed the first photo from each plane. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were used (p < 0.05). The sample comprised 262 images (n = 30). Repeatability was excellent for all three evaluators in all three planes (ICC 0.94 to 1.00). Intrarater reproducibility was excellent in all three planes (ICC 0.88 to 0.99). Interrater analysis was excellent for the frontal and axial planes (ICC 0.98 and 0.93), respectively. However, it was weak in the sagittal plane ICC 0.32. The SEM ranged from 0.02 to 17.6 and MDC from 0.03 to 34.6. The DIPA-S eHealth© Capture and Analysis system demonstrates reproducibility for use in the clinical assessment of scoliosis through teleconsultations.

Flexible UV photodetector based on graphite/titanium dioxide through facile transfer of pencil drawn graphite films on desired substrates

Assembly of graphite structures through pencil drawn method is considered among the most facile and inexpensive approaches for a wide range of electronic and optoelectronic applications. However, the typical limitation of this methodology is that the films and structures can be drawn on a very limited number of substrates. Here, we report a novel methodology for the transfer of pencil drawn graphite films on desired substrate. The graphite films are transferred from cellulose paper, textile and wood paper onto flexible and transparent acrylic tape. The novel wood paper substrate is also used for the fabrication of bar device using a mask which is then transferred onto the acrylic tape. TiO2 nanoparticles paste is coated on the surface of transferred bar device. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and UV–visible spectroscopy of graphite and graphite/TiO2-NPs electrodes are performed respectively to study their morphological, compositional, structural and optical features. The fabricated device acts as a UV photodetector and delivers a photocurrent as higher as 197.68 μA, photoresponsivity of 8.94 mA W−1, detectivity of 4.16 × 109 Jones at bias voltage of 5 V, response time of ∼860 ms and recovery time of ∼890 ms. The flexibility of the demonstrated photodetector is evaluated through recording changes in photocurrent under bending positions from 0 to 150°, and after employing bending cycles up to 1000. The results show that the fabrication of photodetector is facile and low-cost, and it offers valuable working compatibility under bending strains. Moreover, the flexibility of photodetectors enables their effective integration with human skin and clothes for human health monitoring applications.

Ergonomic Design of Noseless Bicycle Saddle using UPVC/Silica-Aerogel

Introduction: During cycling most of the people suffer from perineal pain due to the pressure acting on the perineal area by the nose of the seat. Also Unsupported sitting on the saddle in a forward bending posture for longer time induce low back pain (LBP) among cyclists. So this paper presents the design of noseless bicycle seat with backrest using UPVC/Silica-Aerogel. Methods: This seat is designed as per the anthropometric dimensions of human body. Various parameters such as Lumbar position, seat tilt angle, seat position, backrest angle, seat height, backrest height, seat and backrest width are considered and the optimal value is determined while designing. The material chosen for the base of seat is UPVC/Silica- Aerogel composite and the cushioning material is chosen as polyurethene foam. The design is executed in 3D modelling software and validated using FEA package. Results: The maximum stresses induced in the newly proposed material UPVC/Silica-Aerogel (4.41MPa) is lesser than its yield strength (59 MPa). The maximum anterior stress of noseless seat is found out to be 24.5 kPa which is lower than that of the saddle with nose (41 kPa). Conclusion: As the anterior stress of noseless seat is lesser, the perineal pressure of cyclists is greatly reduced and this decreases the health problems associated with the perineal pressure. Also the backrest of the seatpan enhances the supporting of back muscles and reduces LBP among cyclists.

A simulation study of dual band THz soft antenna for biomedical applications

The demand for multiband and high-gain THz antennas is escalating due to advancements in terahertz (THz) applications, particularly in biomedical conditions. An innovative fork microstrip antenna design has been introduced, operating at THz frequencies, providing multi-band capability, soft characteristics, and high-gain results. The recommended antenna utilizes a series-fed configuration with dual patch elements constructed on a polyethylene substrate, with a thickness of 0.0224 mm, a loss tangent of 0.001, and a permittivity of 2.25. The proposed antenna, with dimensions of 1 × 0.6 × 0.0224 mm³ in its maximum configuration and operating at 0.530 THz and 0.590 THz, exhibits a 10 dB return loss bandwidth of 13 GHz and 15 GHz, respectively. Notably, the realized antenna gain is simulated at 9.01 dBi and 9.53 dBi for their respective frequencies. To assess the antenna's flexibility, simulations are conducted with the antenna configured in bent positions, considering radii of 7 mm, 6 mm, and 5 mm. Furthermore, the study includes an examination of the specific absorption rate (SAR) to validate the suitability of this pliable antenna. The outcomes underscore the potential of the recommended antenna for flexible biomedical THz applications such as the detection of skin tumours and medical imaging.

Analysis of Work Posture and Risk of Musculoskeletal Complaints of Loading-Unloading Workers Using the REBA Method at PT. XYZ

PT XYZ is an airport manager in Indonesia engaged in the business of development, trade and services, and genuine estate. In the manual transportation of goods, extreme positions are still carried out. So that complaints of pain appear in several parts of the body, such as the neck, back, upper arms, and legs. The purpose of this study was to determine musculoskeletal complaints and analyze the work posture of workers. Risk assessment using the Rapid Entire Body Assessment (REBA) method because it can provide a more detailed evaluation of the level of risk of work posture as a whole. Based on the results of risk assessment research using the REBA method, workers in the Loading-Unloading Apron Area squatting position get a work posture risk value of 9, and the Apron Area standing position gets a work posture risk value of 8, where the value includes action level 4. For workers in the Loading-Unloading Makeup Area, the bending position gets a work posture risk value of 11, where the value consists of action level 4. Suggestions for improvement that can be proposed are making changes to the position of work postures and designing assistive devices.

An effective nonlinear dynamic formulation to analyze grasping capability of soft pneumatic robotic gripper

ABSTRACT Soft pneumatic robotic grippers have found extensive applications across various engineering domains, which prompts active research due to their splendid compliance, high flexibility, and safe human-robot interaction over conventional stiff counterparts. Previously simplified rod-based models principally focused on clarifying overall large deformation and bending postures of soft grippers from static or quasi-static perspectives, whereas it is challenging to elaborate grasping characteristics of soft grippers without considering contact interaction and nonlinear large deformation behaviors. To address this, based on absolute nodal coordinate formulation (ANCF), comprehensively allowing for structural complexity, geometric, material and boundary nonlinearities, and incorporating Coulomb’ friction law with a multiple-point contact method, we put forward an effective nonlinear dynamic modeling approach for exploring grasping capability of soft gripper. Moreover, we solved the established dynamic equations using Generalized-α scheme, and conducted thorough numerical simulation analysis on a three-jaw soft pneumatic gripper (SPG) in terms of grasping configurations, displacements and contact forces. The proposed dynamic approach can accurately both describe complicated deformed configurations along with stress distribution and provide a feasible solution to simulate grasping targets, whose effectiveness and precision were analyzed theoretically and verified experimentally, which may shed new light on devising and optimizing other multifunctional SPGs.

Prevalence of neck pain and associated risk factors among the private sector office employees in Bangladesh

Background: Globally, most people face several musculoskeletal problems, especially neck pain. Activities, work styles, and living standards of office employees in Bangladesh vary from place to place. Hence, our aim is to investigate the prevalence of neck pain and related risk factors in Bangladeshi private sector employees. Methodology: A sample was selected to assess neck pain prevalence and related risk factors among 384 private sector employees aged 21–60 years in Bangladesh. Regression analysis was performed on their socio-economic, neck pain, and associated risk factors information through interviews with questionnaires. Results: Data analysis shows that office employees have a relatively higher prevalence rate of cervical pain and it is 34.7%. In this study, we found the results of a logistic regression model to predict factors associated with neck pain. The results of this study indicated that individuals aged 40 years and above, with an OR of 6.148 (P = 0.046) and neck holding the forward bent posture for a prolonged time, were slightly significant to have neck pain (P&lt;0.001). Conclusions: The neck pain prevalence was high among private sector office workers in Bangladesh and some associated neck pain factors were found in this study. The results of our investigation indicated that individuals with higher age, and neck holding position were slightly significant to have neck pain. These research findings also suggest scope for work strategies that can promote a positive work environment, such as short breaks at work and an ergonomic setting.

Mechanically controlled multifaceted dynamic transformations in twisted organic crystal waveguides

This study introduces mechanically induced phenomena such as standing, leaning, stacking, and interlocking behaviors in naturally twisted optical waveguiding microcrystals on a substrate. The microscale twisted crystal self-assembled from 2,4-dibromo-6-(((2-bromo-5-fluorophenyl)imino)methyl)phenol is flexible and emits orange fluorescence. Mechanistic analysis reveals the strain generated by the intergrowing orientationally mismatched nanocrystallites is responsible for the twisted crystal growth. The crystal’s mechanical flexibility in the perpendicular direction to (001) and (010) planes can be attributed to intermolecular Br···Br, F···Br, and π···π stacking interactions. Through a systematic process involving step-by-step bending and subsequent optical waveguiding experiments at each bent position, a linear relationship between optical loss and mechanical strain is established. Additionally, the vertical standing and leaning of these crystals at different angles on a flat surface and the vertical stacking of multiple crystals reveal the three-dimensional aspects of organic crystal waveguides, introducing light trajectories in a 3D space. Furthermore, the integration of two axially interlocked twisted crystals enables the coupling of polarization rotation along their long axis. These crystal dynamics expand the horizons of crystal behavior and have the potential to revolutionize various applications, rendering these crystals invaluable in the realm of crystal-related science and technology.