Back Posture Research Articles

Sex differences in postures of the upper body during a simulated work task performed above shoulder level

The aim of this study was to evaluate if there are sex differences in postures of upper arm, upper back, head and neck after muscle fatigue induced by a simulated work task, requiring upper arm movements performed above shoulder level. Nineteen females and 18 males were evaluated. Upper arm elevation, upper back, head and neck forward flexion postures were recorded using digital inclinometers. The first and the last cycles of the task were considered as pre- and post-fatigue periods, respectively. For both periods, Amplitude Probability Distribution Function (APDF) was calculated for 10th, 50th and 90th percentiles, as well as the angular ranges between the 5th and 95th percentiles (APDF5-95 range). The APDF5-95 range for upper arm elevation was higher with fatigue, but with a higher increase for males. After fatigue, there was also a decrease in the upper arm elevation, with a larger decrease in males for the 10th and 50th percentiles. For head and neck, females showed higher APDF5-95 ranges than males, regardless of the task period evaluated. After muscle fatigue, males adopted more neutral postures of the upper arm than females. Furthermore, females showed more non-neutral postures for head and neck. These findings suggest that the kinematic strategies adopted by females and males during a simulated work task are different and may predispose females to a higher risk of developing work-related musculoskeletal disorders of the neck.

Hybrid artificial genetic – neural network model to predict the transmission of vibration to the head during whole-body vibration training

In this work, Artificial Neural Network (ANN) modelling has been employed to investigate the effects of various factors on the biodynamic responses to vibration represented by the transmissibility and its phase. These factors include, height, weight, Body Mass Index (BMI), age, frequency and posture. Nine subjects stood on a vibrating plate and were exposed to vertical vibration at nine frequencies in the range 17-46 Hz while adopting four different standing postures; Bent Knee posture (BK), Locked Knee posture (LK), right foot to the Front and left foot to the Back posture (FB) and One Leg posture (OL). The accelerations of the vibrating plate and the head of the subjects were measured during the exposure to vibration in order to calculate the transmissibility between the vibrating plate and the head. Genetic Algorithm (GA) was used to choose ANN’s number of hidden layers and number of neurons in each layer to obtain the best performance for predicting the transmissibility. The GA compared the root mean square errors (RMSE) between the ANN outputs and the experimental outputs, and then choose the best results that could be achieved. The number of hidden layers and number of neurons tested in GA vary from one hidden layer to four hidden layers, and from one neuron per layer to one hundred neurons per layer. Several runs have been conducted to train and validate the ANN model. The results show that double hidden layer with 13 neurons in the first layer and 12 neurons in the second layer give the best candidate. The proposed model can be integrated with whole-body vibration machines in order to choose the suitable exposure based on the user’s characteristics.

Prevalence of Neck Pain Among Otolaryngologists

Background: otolaryngologists spend their workdays in performing markedly precise procedures in small works places i.e. the patients’ ear, nose and throat. Due to this, they frequently adopt awkward neck, back and shoulder postures while using devices like otoscope, endoscope and microscope. So, the otolaryngologists’ job profile puts them at high risk for musculoskeletal disorders like neck pain. Purpose: of the study was to investigate the prevalence of work-related neck pain among otolaryngologists - head and neck surgeons. Patients and Methods: specific questionnaire based on Visual Analog Scale and Neck Disability Index was given to one hundred otolaryngologists, head and neck surgeons of both gender, age from 30 to 40 years selected from ENT Departments in Hospitals of Ministry of Health. Results: The statistical analysis revealed that the prevalence of work-related neck pain among otolaryngologists was (69%). Regarding the severity of pain, (80%) reported pain as mild pain while (20%) reported pain as moderate. Conclusion: It could be concluded that work related neck pain is common among Egyptian Otolaryngologists, making otolaryngologists at a high-risk group. There is a need to improve ergonomics in the clinical and operative room settings and to educate otolaryngologists on ergonomic principles.

Standard reference values of the upper body posture in healthy male adults aged between 41 and 50 years in Germany

Background: Classifications of posture deviations are possible when they can be compared to the standard values for healthy persons. Standard values for healthy male adults aged between 41 and 50 years are currently missing. Methods: 100 healthy volunteers (41–50 years old; 45.37 ± 3.06 years) were included in the study. Their body weight ranged from 68 to 132 kg (88.76 ± 15.93 kg), their heights from 1.64 to 2.0 m (1.81 ± 0.07 m) and the Body Mass Index (BMI) ranged from 19.0 kg/m² to 37.7 kg/m² (26.2 ± 3.96 kg/m²). A three-dimensional back scan was performed to quantify the upper back posture during habitual standing. The upper and lower limit for 95% of the tolerance regions and the left and right limit of the confidence interval were calculated. Results: The upper body posture of the subjects was close to the symmetry, or 0°, axis. There was a moderate ventral upper body inclination with a slight left lateral axial deviation and rotation of the spine to the right. An enhanced kyphotic posture was observed in the sagittal plane in the area of the thoracic spine. The shoulder and pelvis areas were almost balanced. Conclusion: Healthy males between 41 and 50 years were found to have an almost balanced posture with minimal ventral body inclination and a marginal scoliotic deviation. These values allow a comparison with other studies for control and patient data and may serve as basis in both clinical practice and scientific studies.

Recording of Motor Unit Potentials Count of Middle Trapezius in Children with Rounded Back

Background: Poor posture is unfortunately wide spreading not only among adults but also among children. Aim of Study: To detect the effect of rounded back posture on the Motor Unit Potentials (MUPs) count of middle trapezius. Patients and Methods: The right and left trapezius motor unit potentials countof 15 normal children (8.64±0.77 years) were compared with 15 children with rounded back (8.92±0.73 years) using electromyography apparatus (EMG). Results: There was a significant increase in the right trapezius motor unit count of the rounded back group compared with that of the normal group (p=0.02). There was no signif-icant difference in the left trapezius motor unit count between the normal and the rounded back groups (p=0.25). Conclusion: Rounded back posture affects the middle trapezius motor unit potential count.

A dataset of radar-recorded heart sounds and vital signs including synchronised reference sensor signals

Radar systems allow for contactless measurements of vital signs such as heart sounds, the pulse signal, and respiration. This approach is able to tackle crucial disadvantages of state-of-the-art monitoring devices such as the need for permanent wiring and skin contact. Potential applications include the employment in a hospital environment but also in home care or passenger vehicles. This dataset consists of synchronised data which are acquired using a Six-Port-based radar system operating at 24 GHz, a digital stethoscope, an ECG, and a respiration sensor. 11 test subjects were measured in different defined scenarios and at several measurement positions such as at the carotid, the back, and several frontal positions on the thorax. Overall, around 223 minutes of data were acquired at scenarios such as breath-holding, post-exercise measurements, and while speaking. The presented dataset contains reference-labeled ECG signals and can therefore easily be used to either test algorithms for monitoring the heart rate, but also to gain insights about characteristic effects of radar-based vital sign monitoring.

Neck Muscular Load When Using a Smartphone While Sitting, Standing, and Walking

Myoelectric activity of neck extensor muscles and head kinematic variables, when using a smartphone for one-handed browsing and two-handed texting while sitting, standing, and walking, were evaluated to compare the neck muscular load during these tasks and across the posture conditions. There has been limited research on the relation between head-down postures and the muscular load on the neck of smartphone users. Twenty-one asymptomatic young users were asked to perform one-handed browsing and two-handed texting tasks in each of the posture conditions, and the myoelectric activities of the neck extensor muscles, head kinematic variables, and upper back posture were quantified. The muscle activation level when using a phone during walking was 21.2% and 41.7% higher than that of sitting and standing on average (p < .01). Head vertical and angular accelerations were also significantly greater (p < .01) for walking than for sitting and standing conditions. Between the two conducted tasks, participants flexed their heads more significantly (p < .01) with higher activation of the neck extensor muscles (p < .01) when texting as compared to when browsing. Results indicate that two-handed texting while walking would be the most physically demanding scenario for neck musculature, and it might be attributable to the dynamics of the head while walking with the head facing downwards. These findings can be used to better understand the potential relation between smartphone use and the occurrence of neck musculoskeletal problems and to inform the users of the ergonomic risks of using smartphones while walking.

Wearable Device to Monitor Back Movements Using an Inductive Textile Sensor.

Low back pain (LBP) is the most common work-related musculoskeletal disorder among healthcare workers and is directly related to long hours of working in twisted/bent postures or with awkward trunk movements. It has already been established that providing relevant feedback helps individuals to maintain better body posture during the activities of daily living. With the goal of preventing LBP through objective monitoring of back posture, this paper proposes a wireless, comfortable, and compact textile-based wearable platform to track trunk movements when the user bends forward. The smart garment developed for this purpose was prototyped with an inductive sensor formed by sewing a copper wire into an elastic fabric in a zigzag pattern. The results of an extensive simulation study showed that this unique design increases the inductance value of the sensor, and, consequently, improves its resolution. Furthermore, experimental evaluation on a healthy participant confirmed that the proposed wearable system with the suggested sensor design can easily detect forward bending movements. The evaluation scenario was then extended to also include twisting and lateral bending of the trunk, and it was observed that the proposed design can successfully discriminate such movements from forward bending of the trunk. Results of the magnetic interference test showed that, most notably, moving a cellphone towards the unworn prototype affects sensor readings, however, manipulating a cellphone, when wearing the prototype, did not affect the capability of the sensor in detecting forward bends. The proposed platform is a promising step toward developing wearable systems to monitor back posture in order to prevent or treat LBP.

Temperature profiling of open- and closed-doored produce cases in retail grocery stores

Temperature control of produce in the retail environment is essential to reduce food safety risks, maintain quality, and reduce food waste. Previous studies have demonstrated that retrofitting or replacing open display cases doors results in better control of temperature and humidity. However, there are no studies to date that comprehensively evaluate temperature profiles in cases with and without doors in actual retail store environments. Twenty-five open and closed refrigerated display cases in ten retail stores in five states were monitored for temperature and humidity over 9 months. Sensors recorded data every 2 min at eight positions (top, middle, bottom and under the bottom bin, in the front and back locations of each shelf). There were significant differences between open and closed cases, retailers, and sensor position in display cases on temperature and relative humidity (p < 0.0001). Seven display cases were retrofitted with doors and, as a result, temperature variations were significantly minimized (p-value <0.0001). Cases with doors maintained temperatures significantly lower (4.7 °C, p-value <0.0001) than cases without doors, and the top front position in the cases had both the highest temperature (5.7 °C) and abuse due to high temperature (>5 °C) for the longest duration (35.7% of total time observed) of allow locations measured. Temperatures and abuse conditions above 5 °C were not significantly different between front and back positions in the cases. The range of temperature and RH variability was reduced following door installation. With changes in display case technology over the past five years, this study provides updated data on operational temperatures in display cases before and after retrofitting with doors. It also provides evidence of the importance of temperature monitoring within display cases to ensure abusive conditions do not persist.

Individualised automated lameness detection in dairy cows and the impact of historical window length on algorithm performance

Lameness is an important economic problem in the dairy sector, resulting in production loss and reduced welfare of dairy cows. Given the modern-day expansion of dairy herds, a tool to automatically detect lameness in real-time can therefore create added value for the farmer. The challenge in developing camera-based tools is that one system has to work for all the animals on the farm despite each animal having its own individual lameness response. Individualising these systems based on animal-level historical data is a way to achieve accurate monitoring on farm scale. The goal of this study is to optimise a lameness monitoring algorithm based on back posture values derived from a camera for individual cows by tuning the deviation thresholds and the quantity of the historical data being used. Back posture values from a sample of 209 Holstein Friesian cows in a large herd of over 2000 cows were collected during 15 months on a commercial dairy farm in Sweden. A historical data set of back posture values was generated for each cow to calculate an individual healthy reference per cow. For a gold standard reference, manual scoring of lameness based on the Sprecher scale was carried out weekly by a single skilled observer during the final 6 weeks of data collection. Using an individual threshold, deviations from the healthy reference were identified with a specificity of 82.3%, a sensitivity of 79%, an accuracy of 82%, and a precision of 36.1% when the length of the healthy reference window was not limited. When the length of the healthy reference window was varied between 30 and 250 days, it was observed that algorithm performance was maximised with a reference window of 200 days. This paper presents a high-performing lameness detection system and demonstrates the importance of the historical window length for healthy reference calculation in order to ensure the use of meaningful historical data in deviation detection algorithms.

Playing-Related Injuries and Posture Among Saxophonists.

Playing-related injuries are common among musicians, but little is known about the nature of injuries and complaints in saxophone players. This research explored playing-related musculoskeletal disorders (PRMDs) and postures among saxophonists. The aims were to: 1) investigate the prevalence of PRMDs among saxophonists; 2) determine the most problematic body parts; and 3) identify their main postural habits and determine whether these postural habits may be related to the prevalence of pain in specific body parts. An online questionnaire was used to collect data from professional and college-level saxophonists throughout North America. From 109 saxophonists who responded, 83 (76.15%) reported ever having a PRMD, 54 (50%) reported having a PRMD in the past year, 30 (27.52%) reported having a PRMD in the past month, and 23 (21.10%) reported having a PRMD in the past week. Top rated areas of pain were the right wrist, neck, mouth/jaw, and left wrist. The most common self-reported postural habits were forward head position and rounded upper back. Postures that correlated with higher pain ratings were rounded upper back and backward pelvic tilt. The rounded upper back, backward pelvic tilt, and excessive curve in low back postures were significantly correlated with the presence of PRMD problems in the right wrist. Saxophonists in this survey experienced a high prevalence of PRMDs, especially of the wrists, neck, and mouth/jaw. Certain postural habits may contribute to higher pain ratings or PRMD locations within saxophonists.

Passing Network Analysis of Positional Attack Formations in Handball.

The aim of this study was to characterize handball from a social network analysis perspective by analyzing 22 professional matches from the 2018 European Men's Handball Championship. Social network analysis has proven successful in the study of sports dynamics to investigate the interaction patterns of sport teams and the individual involvement of players. In handball, passing is crucial to establish an optimal position for throwing the ball into the goal of the opponent team. Moreover, different tactical formations are played during a game, often induced by two-minute suspensions or the addition of an offensive player replacing the goalkeeper as allowed by the International Handball Federation since 2016. Therefore, studying the interaction patterns of handball teams considering the different playing positions under various attack formations contributes to the tactical understanding of the sport. Degree and flow centrality as well as density and centralization values were computed. As a result, quantification of the contribution of individual players to the overall organization was achieved alongside the general balance in interplay. We identified the backcourt as the key players to structure interplay across tactical formations. While attack units without a goalkeeper were played longer, they were either more intensively structured around back positions (7 vs. 6) or spread out (5 + 1 vs. 6). We also found significant differences in the involvement of wing players across formations. The additional pivot in the 7 vs. 6 formation was mostly used to create space for back players and was less involved in interplay. Social network analysis turned out as a suitable method to govern and quantify team dynamics in handball.

Anthropometric Engineering Approach in Conceptual Design of Sleeping Pillow

Introduction: Sleep is an essential element for maintaining health, which is associated with several factors in improving its quality, including the use of a suitable pillow that, with effective support, can support the spine in the neck area and it prevents complications such as headache, neck pain and shoulder pain .The purpose of this study was to provide a suitable pillow design in accordance with the dimensions of Iranian people for proper support in both back and flank positions. Materials and Methods: 84 volunteers (40 males and 44 females) with an average age of 29/47 years (SD=7/91) were enrolled. Anthropometric characteristics such as head width in the ear area, head length, head height, etc. were determined using a caliper, a Canon SX60HS camera, a digimizer software, Excel and SPSS version 20. Different percentiles of the body dimensions of men and women were calculated. The findings were used to calculate the dimensions of different parts of the ergonomic pillow. Results: Based on different dimensions of the head, neck and shoulder area in the sample, the pillow was designed with a width of 70 and a depth of 26/4 cm for men and a width of 65 and a depth of 26/4 cm for women. Discussion and Conclusion: It is anticipated that the pillow designed according to anthropometric measurements of Iranian subjects can reduce head and neck pain and spinal problems. It is also recommended that other research has to be done to standardize the dimensions and type of pillow material in all parts of Iran.

Neck muscle activation and head kinematics when using a smartphone while walking

Using a smartphone while walking has been common in countries with high smartphone penetration rates. While pedestrian safety issues have been studied frequently, research regarding ergonomics issues such as neck discomfort of smartphone use while walking has been limited. An experimental study was conducted to evaluate the neck muscular load of smartphone use while walking. Twenty-one asymptomatic young smartphone owners conducted one-handed browsing and two-handed texting while walking on a treadmill. Their neck muscle activation level, head and upper back posture were quantified. Compared to when walking upright without using a smartphone, the two smartphone-use tasks demanded 33.3% to 101.8% more activation of the neck extensor muscles. Mean head tilt angles (relative to upright standing) were 28.9° and 36.9° for the one-handed browsing and two-handed texting, respectively. Between the two smartphone tasks, the head tilt angle and the muscle activation level were significantly greater for texting than for browsing. Results indicated that conducting two-handed texting while walking would pose larger muscular load to the neck extensor muscles compared to when conducting one-handed browsing while walking due to the larger head tilt angle.

Gas-filled urachal abscess with a pinging sound in a heifer calf

A 6-month-old crossbred of a Holstein and Japanese Black heifer calf weighing 95 kg presented with a history of intermittent abdominal distension and failure to thrive. The physical examination identified a pinging sound over the dorsal left flank. The abdominal radiography showed a huge gas-filled mass. The intravenous urography revealed no communication between the mass and the urinary bladder. Although the visual examination and palpation of the umbilicus did not reveal visible abnormalities, an umbilical disease was suspected because the animal exhibited poor growth, depression, and a hunched back posture. When the eschar adhering to the centre of the umbilicus was removed, the presence of a fistulous tract was revealed. The umbilical ultrasound examination revealed an intra-abdominal abscess and the fistulography demonstrated that the abscess communicated with the umbilicus. The abscess, compressing into the rumen, was observed by computed tomography. From these images, it was diagnosed as an umbilical cord remnant abscess and a definitive diagnosis of a urachal abscess was obtained by open abdominal surgery and the subsequent removal of the mass. The calf was discharged from the university hospital on day 14 after the operation. This case shows that a urachal abscess should be considered when a pinging sound is present, even if the animal exhibits no swelling or pain of the umbilicus.

Upper back pain in postmenopausal women and associated physical characteristics.

The physical characteristics of postmenopausal women that are associated with upper back pain are not well-understood. The aim of this cross-sectional study was to identify the physical characteristics associated with presence and severity of upper back pain in healthy postmenopausal women. Self-reported upper back pain presence (within the previous month) and severity (numerical rating scale) were examined against the physical characteristics: height; weight; body mass index; breast size; breast ptosis; upper back extensor muscle endurance (isometric chest raise test); head, shoulder and upper back posture (photogrammetry); thoracic extension mobility (photogrammetry); bone mineral density (dual-energy x-ray absorptiometry (DXA)); body composition (DXA); and thoracic kyphosis, thoracic osteoarthritis and thoracic vertebral fracture (all radiography). A multivariable logistic regression model, adjusted for age, was built using physical characteristics with a significant univariate association with upper back pain. Censored Tobit regression, adjusted for age, was used to examine each physical characteristic against upper back pain severity. Postmenopausal women (n = 119) with a mean (SD) age of 61.4 (7.0) years participated in the study. After adjusting for age, the physical characteristics independently associated with upper back pain were: height (OR: 0.50, 95% CI: 0.31–0.79); and upper back extensor muscle endurance (OR: 0.46, 95%CI: 0.28–0.75). This model explained 31% of the variance in upper back pain (p<0.001). After adjusting for age, being taller and having better upper back extensor muscle endurance were associated with lower odds for upper back pain. After adjusting for age, differences in upper back pain severity were explained by upper back extensor muscle endurance (p = <0.001) and lean mass (p = 0.01). Conclusion: As a modifiable physical characteristic of postmenopausal women with upper back pain, upper back extensor muscle endurance is worth considering clinically.

Generic Dry-Contact Ear-EEG.

Generic dry-contact ear-EEG allows for discreet, user-friendly, unobtrusive, cost-effective and convenient recordings of EEG in real-life settings. In this study we introduce a new generic earpiece design with larger internal ear electrode distances, resulting in an increased spatial coverage compared to previous generic earpiece designs. The signal quality of ear-Fpz, within-ear (the measuring and reference electrode located in the same ear) and cross-ear (the measuring electrodes located in one ear and the reference electrode in the opposite ear) electrode configurations of the developed generic earpiece was evaluated with auditory steady-state responses (ASSR) and compared to dry-contact cEEGrid. Ten subjects with different ear sizes were included. The recordings were performed in a sleep setup, where the subjects were lying on a bed and the effect of sleeping position (back vs. sides) was investigated. We found that the generic earpiece attained statistically significant ASSRs with ear-Fpz, within-ear and cross-ear electrode configurations. However, the dry-contact cEEGrid achieved significantly higher average ASSR signal-to-noise ratio (SNR) compared to the generic earpiece. Additionally, this study showed no significant difference between back and side positions for the ear-EEG.

Manual Cultivation Operations in Poplar Stands: A Characterization of Job Difficulty and Risks of Health Impairment.

Short rotation poplar forests are a viable alternative in producing high quality wood for industrial applications. Their success depends on timely and high-quality implementation of a series of operations. Weed control operations are implemented to favor the trees in their competition for soil resources, and cultivation is an option typically used in many European countries. For the moment, a complete mechanization of such operations is virtually impossible, and they still require an intensive use of manual labor. Since information on work difficulty and risks in manual cultivation operations is limited, this study aimed to characterize this job. Evaluation was made in terms of work efficiency, cardiovascular workload, work intensity and postural risks by implementing a time and motion study combined with heart rate measurements, accelerometry and whole-body postural analysis. Work efficiency was particularly low even if the share of effective work time was high (70% of the observation time). Job was characterized as moderate to high intensity, which resulted into a moderate to high cardiovascular strain. While the postural analysis indicated rather small risks, the main problem was found for the back postures assumed during the work. Improvements should aim to extend mechanization, train the workers and appropriately design rest breaks.

Relative Age Effect is Modulated by Playing Position but is Not Related to Competitive Success in Elite Under-19 Handball Athletes.

This study aimed to verify the occurrence of the relative age effect (RAE) in male elite young handball athletes according to the playing position and its association with team performance in a World Championship. Data from 383 handball athletes from 24 countries who participated in the 7th World Men’s Championship in the under-19 category were analyzed. RAE was investigated from the birth trimester of the athletes, their playing position, and final ranking in the Championship. The results showed an overrepresentation of athletes born in the first two trimesters (Q1 and Q2) (χ2(3) = 32.97; p < 0.001, ω = 0.29). The analysis of the athlete’s position showed that most wings (χ2(3) = 18.37; p < 0.001, ω = 0.32) and backs (χ2(3) = 12.51; p = 0.006, ω = 0.34) were born in the first trimesters (Q1 and Q2). The ranking in the Championship presented no significant association with the date of the birth (p > 0.05). The results showed the existence of the RAE in youth handball elite athletes, especially for the back and wing positions. However, the strategy of selecting is questionable once the presence of RAE was not associated with competitive success.

TILAA: Tactile Internet-based Ambient Assistant Living in fog environment

Abstract Ambient assisted living provides an environment to aid regular activities (such as exercise, medical diagnosis etc.) for well being of users. In this direction, posture correcting mechanisms can be developed to have a real-time detection and correction system, which allow doctors and caregivers to monitor the patients’ health without worrying about potential falls and backaches. Most of the data related to patient health resides on the cloud environment to be accessed from anywhere by different users. However, the existing cloud computing infrastructure does not support a quick feedback for posture correction by the patients located geographically separated locations.However, with the advent of 5G networks, a new networking paradigm of Tactile Internet emerges having low latency communication for ubiquitously connecting heterogeneous devices at the edge of the network. Keeping focus on these issues, we propose, TILAA, a framework for Tactile Internet-based Ambient Assistance Living in fog environment in this paper. It provides a collaborative communication feedback to the patients and doctors with reduced delay. TILAA consists of a micro controller, sensing devices such as-accelerometer and gyroscopes, and a battery holder. The straps on the chest wearable consist of actuators, which send vibrations as a Tactile feedback to the doctors or to the hospitals for taking proactive measures in case of emergency. Performance evaluation of TILAA shows that it has superior performance for the back posture of all patients as compared to pre-existing expensive detection and posture schemes.