Postural Measures Research Articles

Postural stability measures as diagnostic tools for chronic ankle instability: a comprehensive assessment

BackgroundChronic ankle instability (CAI) is characterized by recurrent sprains and persistent symptoms, which impair postural control. This study evaluates the diagnostic utility of various linear and nonlinear postural stability measures in distinguishing individuals with CAI from healthy controls.MethodsPostural stability was assessed in 24 participants (12 with CAI and 12 healthy controls) using a force platform under four conditions: hard surface with eyes open, hard surface with eyes closed, soft surface with eyes open, and soft surface with eyes closed. Linear measures of center of pressure (COP) included range in the anteroposterior (Rfa) and mediolateral (Rsw) directions, mean velocity (MV), and sway area. Nonlinear measures included approximate entropy (ApEn), the largest Lyapunov exponent, and correlation dimension (CD) with its standard deviation. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) analysis to determine cutoff scores, allowing effective differentiation between CAI and healthy participants.ResultAI individuals exhibited increased mediolateral COP sway and higher mean velocity on hard surfaces with both eyes open and closed. On soft surfaces with eyes closed, they showed significant deficits in sway area and mean velocity, reflecting challenges in postural control. ROC analysis revealed that certain linear and nonlinear measures showed strong diagnostic accuracy in distinguishing individuals with CAI from healthy controls. Nonlinear analysis revealed elevated ApEn and reduced CD in CAI participants, indicating greater postural irregularity and reduced dynamic stability. On a hard surface with eyes open both Rsw (cutoff: 1.18 cm, OR: 4.55) and ApEn (cutoff: 0.07, OR: 4.0) were particularly strong diagnostic indicators.ConclusionLinear and nonlinear postural stability measures effectively differentiate individuals with CAI from healthy controls. Key metrics, including Rsw, MV, ApEn, and CD, offer strong diagnostic value for early detection and personalized rehabilitation. Incorporating these measures into clinical practice may improve CAI management and patient outcomes.Ethical codeIR.TUMS.FNM.REC.1400.236. March 14, 2022.

Personalized estimating metabolic equivalents by an integration system of marker-less motion capture, portable 3D scanner and calculation of mechanical work

This study aimed to develop a personalized exercise evaluation technology that can simultaneously and accurately estimate metabolic equivalents (METs) and postural measurement during exercise to provide personalized training content, exercise intensity, and competition time according to the individual. To this end, we developed a measurement system that integrates three technologies: marker-less motion capture, human body dimension measurement, and METs estimation based on mechanical energy. For validation, the METs obtained from the exhaled gas analyzer were used as the true value, and the accuracy was compared with that estimated by an activity meter, a standard method. The test conditions included 10 adult male participants and nine different test events with varying proportions of upper and lower limbs. The validity test results showed that the estimation accuracy was equivalent to that of an activity meter. In addition, since the proposed method estimates the posture during exercise, it is possible to analyze the causes of the differences in the METs between participants in the same test. In this study, a method for estimating METs based on mechanical energy is proposed and validated. This method considers the effect of body shape since it uses marker-less motion capture to evaluate motion. The regression coefficients necessary for MET estimation are based on data from 19 participants (male:female ratio 16:3) aged 19–33 years old, and the validity evaluation was conducted on 10 male participants aged 22–24 years old. Future studies should assess the applicability of the METs estimation to other populations with relatively different body composition rates, such as males and pregnant and non-pregnant females.

Evaluating Tech Neck: A Pilot Study Using a Self-Developed Questionnaire on Symptoms, Posture, and Preventive Measures.

Musculoskeletal symptoms, such as neck pain, back pain, and eye strain, are prevalent in modern work environments, particularly among individuals engaged in prolonged sitting and repetitive tasks. This study aimed to explore the prevalence of these symptoms and the impact of ergonomic tool usage, break frequency, posture awareness, and proactive measures on symptom intensity and daily functioning. This cross-sectional pilot study used a self-developed questionnaire to assess the prevalence and intensity of musculoskeletal symptoms among participants aged 6-18 years. The survey collected data on ergonomic tool usage, break frequency, posture awareness, and proactive measures (such as taking breaks and seeking professional help). Symptom intensity was assessed across common musculoskeletal issues. Internal consistency was assessed using Cronbach's Alpha. Statistical analyses, including descriptive statistics, Chi-squared tests, ANOVA, and Spearman's correlation, were used to identify significant correlations and associations between variables. A significant proportion of participants reported moderate to severe symptoms, including neck pain, back pain, and eye strain. Participants who used ergonomic tools reported significantly lower symptom intensity (<0.001). A positive correlation was found between fewer breaks and higher symptom intensity (r = 0.908, p < 0.001). Those with higher posture awareness reported lower symptom intensity (p < 0.001). Proactive measures, including regular breaks and ergonomic interventions, were perceived as effective strategies for managing symptoms. Increased symptom intensity was associated with reduced ability to perform daily activities (p < 0.001). The study highlights the significant role of ergonomic tools, posture awareness, and regular breaks in mitigating musculoskeletal symptoms. Proactive measures, including structured interventions, can effectively reduce symptom intensity and improve daily functioning. These findings suggest that workplace health strategies focusing on ergonomics and posture education are crucial for reducing the impact of musculoskeletal discomfort on employee well-being and productivity.

Reliability and Accuracy of Standard Reference Procedures for Measurements of Trunk and Arm Postures in Ergonomics.

Adequate reference procedures for obtaining the reference zero-angle position are important for precise and accurate posture measurements, but few studies have systematically investigated these. A limited number of previous studies suggest differences in accuracy between procedures, with some causing an underestimation of the true arm elevation angle when sensors are taped to the skin. The reliability of commonly used reference procedures for the measurement of the trunk posture is also not well explored, and alternative procedures may improve precision. Based on this identified gap, this study evaluated the test-retest reliability of the N-position (I-pose), i.e., the standard procedure for recording trunk postures, and compared it with two new alternative procedures. Additionally, the accuracy of the N-position for measuring arm elevation angles was compared with one alternative procedure. A total of 40 participants (22 women and 18 men) aged 26-70 years performed the reference procedures in a laboratory setting. Postures were recorded using a smart workwear system equipped with two inertial measurement units (IMUs) embedded in pockets within the workwear. For the trunk posture, the N-position showed a slight lack of test-retest reliability, while one of the alternative procedures demonstrated better test-retest reliability. For the arm posture, the N-position, which does not include lateral trunk inclination, resulted in a substantial underestimation of the arm elevation angle of approximately 15°, which is a novel finding. In contrast, the posture involving trunk inclination closely matched the targeted reference, with a difference of less than 2°. This study underscores the importance of selecting appropriate reference procedures to ensure precise and accurate posture measurements.

Digital Health Technologies for Optimising Treatment and Rehabilitation Following Surgery: Device-Based Measurement of Sling Posture and Adherence

Background: Following shoulder surgery, controlled and protected mobilisation for an appropriate duration is crucial for appropriate recovery. However, methods for objective assessment of sling wear and use in everyday living are currently lacking. In this pilot study, we aim to determine if a sling-embedded triaxial accelerometer and/or wrist-worn sensor can be used to quantify arm posture during sling wear and adherence to sling wear. Methods: Four participants were asked to wear a GENEActiv triaxial accelerometer on their non-dominant wrist for four hours in an office environment, and, for two of those hours, they also wore a sling in which an additional GENEActiv accelerometer was secured. During sling wear, they were asked to move their arm in the sling through a series of pre-specified arm postures. Results: We found that upper arm angle and posture type during sling wear can be predicted from a sling sensor alone (R2 = 0.79, p &lt; 0.001 and Cohen’s kappa = 0.886, respectively). The addition of a wrist-worn sensor did not improve performance. The optimisation of an existing non-wear algorithm accurately detected adherence (99.3%). Conclusions: the remote monitoring of sling adherence and the quantification of immobilisation is practical and effective with digital health technology.

Vection in Individuals with and without Concussion: Associations with Postural Responses and Visual Dependence

Background We investigated whether everyday situations that trigger post-concussion symptoms (i.e., dynamic visual scenes), induce vection (illusory self-motion) and/or affect postural stability. Materials &amp; Methods Concussed and control participants were moved through a virtual grocery store, and rated their vection intensity. Postural sway during visual motion was measured. Baseline tests assessed concussion symptoms and sensory functioning, including visual dependence. Results Vection ratings were higher in concussed individuals than controls, and were predicted by faster visual speeds. Vection and visual speed also predicted postural sway in the concussion group. Visual dependence was positively associated with vection intensity and all postural measures. Conclusion These findings provide valuable insights for the development of future symptom-screening tools and rehabilitation strategies.

Breathing and relaxation exercises as part of a wellness routine for men in executive positions

Introduction: The health state of male executives who are exposed to high levels of stress has yet to be thoroughly studied. Breathing and relaxation exercises could serve as an appropriate wellness routine to help them manage stressful conditions in the workplace as well as to prevent health problems related to an unhealthy lifestyle. Aim: Our study comprises several phases and the objectives of each phase were chosen accordingly. In the first phase of our pilot study, we aimed to determine how effective a six-week exercise intervention program would be in promoting the mental and physical health of a selected group of men in executive positions. In the subsequent stages, we investigated how the programme served to educate these men and whether the participants continued an exercise routine over the next two years. Methodology: Our research was based on a case-by-case evaluation of 10 men aged 35-55 years who work in executive top management positions. The men were asked to take part in several research surveys (8 in total) in a period of two years. After an initial assessment which included: an anamnestic examination and medical history, an assessment of posture and an anthropometric indicators, questionnaires, the men's so-called weak points were defined. On the basis of these weaknesses, a simple routine consisting of breathing and relaxation exercises was developed. The participants were instructed to performe this routine once a day for 15 minutes. The assessment methods included: czech questionnaire about manifestation of burnout syndrome "Inventář Projevů Syndromu Vyhoření" (IPSV), the Q8+1 self-esteem questionnaire ("Self-awareness"), an aspectual examination of body posture and anthropometric measurements (chest elasticity, wais/hip ratio index), the visual examinaton and anthropometric indicators measurements (chest elasticity, waist-hip ratio). These assessment were repeated several time the baseline assessment, during therapeutic programme; after the intervention; eight weeks after the intervention; and the followed up assessment two years after initiation of the study. Results: This pilot study indicate that after of the therapeutic program, there was an improvement in all assessed outcomes. Our research revealed that it is possible to attain improvements in psychological wellbeing as well as in some anthropometric parameters (chest elasticity) through targeted exercise intervention. However, almost all outcomes that showed improvement after completion of the program reverted to their original values after two years. None of the men involved in the study persisted with regular exercise, even though all of them acknowledged the positive impact the program had on their well-being.

Impact of Diaphragm-Strengthening Core Training on Postural Stability in High-Intensity Squats.

This study analyzed the effects of an 8-week diaphragmatic core training program on postural stability during high-intensity squats and examined its efficacy in injury prevention and performance enhancement. Thirty-seven male participants were randomly assigned to three groups: diaphragmatic core training group (DCTG, n = 12), core training group (CTG, n = 13), and control group (CG, n = 12). Outcome measurements included diaphragm thickness, respiratory function (mean and maximal respiratory pressures), and squat postural stability (distance between the sacral and upper body center points, peak trunk extension moment, peak knee flexion moment, and dynamic postural stability index). Compared to both CTG and CG, DCTG demonstrated significantly greater improvements in diaphragm thickness (DCTG: 34.62% increase vs. CTG: 1.36% and CG: 3.62%, p < 0.001), mean respiratory pressure (DCTG: 18.88% vs. CTG: 1.31% and CG: 0.02%, p < 0.001), and maximal respiratory pressure (DCTG: 18.62% vs. CTG: 0.72% and CG: 1.90%, p < 0.001). DCTG also showed superior improvements in postural stability measures, including reductions in the distance between sacral and upper body center points (DCTG: -6.19% vs. CTG: -3.26% and CG: +4.55%, p < 0.05), peak trunk extension moment (DCTG: -15.22% vs. CTG: -5.29% and CG: +19.31%, p < 0.001), and dynamic postural stability index (DCTG: -28.13% vs. CTG: -21.43% and CG: no change, p < 0.001). No significant between-group differences were observed in peak knee flexion moment. Core training incorporating diaphragmatic strengthening was more effective than conventional training in improving postural stability during high-intensity squats. Core training programs, including diaphragmatic strengthening exercises, may contribute to injury prevention and performance enhancement in exercises requiring lumbar stability, such as squats.

Predicting future fallers in Parkinson’s disease using kinematic data over a period of 5 years

Parkinson’s disease (PD) increases fall risk, leading to injuries and reduced quality of life. Accurate fall risk assessment is crucial for effective care planning. Traditional assessments are subjective and time-consuming, while recent assessment methods based on wearable sensors have been limited to 1-year follow-ups. This study investigated whether a short sensor-based assessment could predict falls over up to 5 years. Data from 104 people with PD without prior falls were collected using six wearable sensors during a 2-min walk and a 30-s postural sway task. Five machine learning classifiers analysed the data. The Random Forest classifier performed best, achieving 78% accuracy (AUC = 0.85) at 60 months. Most models showed excellent performance at 24 months (AUC > 0.90, accuracy 84–92%). Walking and postural variability measures were key predictors. Adding clinicodemographic data, particularly age, improved model performance. Wearable sensors combined with machine learning can effectively predict fall risk, enhancing PD management and prevention strategies.

Measuring international posture at an internationalised university in Barcelona: an exploration of gender, language, and educational and intercultural trajectories

ABSTRACT This study investigates local first-year undergraduates’ international posture (Yashima, 2002, 2009) when starting studies at an internationalised university in the multicultural and multilingual context of Barcelona (Catalonia, Spain). We aimed, first, to explore the configuration of the international posture measurement model (Yashima, 2009) in a European university and to contrast it with Yashima’s (2009) model developed in Japan. Second, we aimed to investigate what individual variables interact with students’ degree of international posture. Five hundred and two students answered two questionnaires covering their background profile and Yashima’s international posture scale. Factor analyses and descriptive and inferential statistics were performed. Our analysis resulted in three sub-scales with a total of 14 items, in contrast to Yashima’s original 20 items structured into four sub-scales. Higher scores were reported for questionnaire items focused on intergroup relationships in local contexts rather than interactions abroad. Regarding individual variables, being a female and having intercultural friendships emerged as the most predictive factors. In contrast, individual plurilingualism, readiness to move within the country for university studies, and choosing a degree with a high proportion of English-medium instruction only partially predicted undergraduates’ high international posture in this European higher education context.

Identification of Balance biomarkers using Inertial sensor for Early Detection of Dementia

AbstractBackgroundEarly‐stage dementia, Mild Cognitive Impairment (MCI), is challenging to diagnose since it is a transient condition distinct from complete cognitive collapse. Recent clinical research studies have identified that balance impairments can be a significant indicator for predicting dementia in older adults. Accordingly, we aimed to identify key balance biomarkers using wearable inertial sensors for early detection of dementia/MCI.MethodAt National Research Center for Dementia (South Korea), 60 participants (30 Cognitively Normal‐CN, 30 Mild Cognitive Impairment‐MCI) were selected based on assessments conducted by medical professionals at Chosun University Hospital / Chonnam National University Hospital (Gwangju). Shimmer‐3 inertial sensor was placed on lower back of participants, with a tri‐axial accelerometer and tri‐axial gyroscope. The data was collected under four different conditions: eyes‐open (EO), eyes‐closed (EC), right‐leg lift (RL), left‐leg lift (LL). A set of 76 postural sway measures were considered with 43 time‐domain and 33 frequency‐domain features.Feature ranking was executed through the utilization of "Leave‐One‐Subject‐Out (LOSO)" cross‐validation technique for each condition. Filter methods: one‐way‐ANOVA (Analysis of Variance), Mutual Information and Wrapper methods: Random Forest, Support Vector Machine (SVM) were utilized to evaluate feature subsets. The proportional value of each feature was calculated by the number of times it showed in the top feature list. The final score was obtained by combining scores from all the techniques, which indicated the relative weight of characteristics across the various approaches. Further feature analysis was conducted using SHAP (Shapley‐Additive‐exPlanations).ResultThe multi‐step methodology, for feature selection, adopted in our research ensured a rigorous process, combining the strengths of Filter and Wrapper methods. In time‐domain: root‐mean‐square, mean‐distance, 95%‐confidence circle sway‐area, path‐length, mean sway‐velocity were the key features identified. While in frequency‐domain: spectral edge‐frequency, mean‐frequency, peak‐frequency, centroid‐frequency, spectral‐entropy were found to be the principal features of relevance. These features were also included in the top list of features based on SHAP impact value, hence proving the effectiveness of our method in identifying important biomarkers for detection of MCI.ConclusionThe inertial sensors based postural balance assessment provides useful biomarkers that can facilitate early screening of MCI / dementia in home settings.

Differences in spinal axial rotation angles during the lumbar-locked rotation test between hyper and normal thoracic rotation groups: A cross-sectional study.

Trunk rotation is important in many sporting activities The thoracic spine has reciprocal relationships with the lumbar and pelvic spines, such that reduced flexibility in the lumbar or thoracic spine can lead to abnormal patterns of trunk movement and pain. However, few studies have investigated the relative trunk rotation mobilities of the thorax, lumbar, and pelvis. To compare thoracic, lumbar, and pelvic rotation angles during the lumbar-locked rotation test between hyper and normal thoracic rotation groups. Thirty-two young, active participants were enrolled in this study. After the attachment of inertial measurement units at the T1, T7, T12, L3, and S2 levels, the participants were required to stand in a comfortable upright posture for 5s to allow postural measurements before performing the lumbar-locked rotation test. The participants were then divided into hyper thoracic rotation and normal thoracic rotation groups based on T1 angle measurements obtained during the lumbar-locked rotation test. The hyper thoracic rotation group had significantly higher thoracic rotation angles on both the right (p< 0.05) and left (p< 0.05) sides compared with the normal thoracic rotation group. Furthermore, we observed flat lumbar lordosis in the hyper thoracic rotation group compared with the normal thoracic rotation group, particularly in the lower lumbar region in standing posture. Our data suggest that evaluations of thoracic mobility should consider relative thoracic, lumbar, and pelvic motions, rather than the T1 angle alone. This study provides a basis for health professionals to evaluate movement dysfunctions associated with thoracic hypermobility.

Lasting Deficiencies in Vergence Eye Movements in Patients with Peripheral or Central Vertigo: Improvements After Four Sessions of REMOBI Neurotraining and Associated Functional Benefits.

The vestibular function is in synergism with the oculomotor vergence. Vertigo may be related to vergence disorders and conversely, vestibular pathologies may affect vergence. To consolidate this hypothesis, we conducted a study at the vestibular orthoptic clinic of the Bastogne Hospital. Fourteen patients with vertigo history appearing 2 weeks to 8 years ago, aged 30 to 65 years were studied; at the moment of the eye movement study, no patient had acute attack of vertigo. The origin of vertigo varied (Meniere's disease, organic pathology, sensitivity to visual movement). An assessment with objective measurement of vergence (single-step protocol) was carried out with the REMOBI technology coupled with binocular video-oculography in sitting and standing positions. Four neuro-rehabilitation sessions of vergence eye movements were performed with the double-step in-depth protocol, alternating sitting and standing positions to involve different postural and vestibular functions. An assessment of vergence was done again 1 to 2 months later. The initial assessment revealed problems of magnitude and/or speed or variability of vergence for 11 of the patients relative to controls (published by the group in previous studies). After neuro-rehabilitation, an improvement was observed in eight patients. Patients reported a clear improvement of their self confidence in moving in the space. Posture measures done before rehabilitation comparing eyes fixating or closed or while making near-far vergence eye movements indicated lower medio-lateral acceleration when doing vergence eye movements in patients with vertigo history of functional origin. The results are in favor of the hypothesis of a symbiosis between vergence and vestibular function and the interest of diagnosis and rehabilitation of the vergence disorder in patients with vertigo history in the absence of acute vertigo attack.

Construct Validity of a Wearable Inertial Measurement Unit (IMU) in Measuring Postural Sway and the Effect of Visual Deprivation in Healthy Older Adults.

Inertial Motor sensors (IMUs) are valid instruments for measuring postural sway but their ability to detect changes derived from visual deprivation in healthy older adults requires further investigations. We examined the validity and relationship of IMU sensor-derived postural sway measures compared to force plates for different eye conditions in healthy older adults (32 females, 33 males). We compared the relationship of the center of mass and center of pressure (CoM and CoP)-derived total length, root means square (RMS) distance, mean velocity, and 95% confidence interval ellipse area (95% CI ellipse area). In addition, we examined the relationship of the IMU sensor in discriminating between open- (EO) and closed-eye (EC) conditions compared to the force plate. A significant effect of the instruments and eye conditions was found for almost all the variables. Overall, EO and EC variables within (force plate r, from 0.38 to 0.78; IMU sensor r, from 0.36 to 0.69) as well as between (r from 0.50 to 0.88) instruments were moderately to strongly correlated. The EC:EO ratios of RMS distance and 95% CI ellipse area were not different between instruments, while there were significant differences between total length (p = 0.973) and mean velocity (p = 0.703). The ratios' correlation coefficients between instruments ranged from moderate (r = 0.65) to strong (r = 0.87). The IMU sensor offers an affordable, valid alternative to a force plate for objective, postural sway assessment.

The effect of height of lifting on dynamic postural control in low back pain patients and healthy subjects

Objectives: The study investigated the influence of starting load position during lifting on postural control in nonspecific chronic low back pain (LBP) and healthy volunteers. Patients and methods: The cross-sectional study included 20 healthy males (mean age: 31.8±7.4 years; range, 18 to 55 years) and 52 male patients (mean age: 33.4±9.2 years; range, 18 to 55 years) with chronic LBP between February 2016 and April 2018. Postural control characteristics were assessed by a force plate system. Center of pressure signals were obtained at a frequency of 100 Hz, and the mean of three trials was calculated. The participants were told to place their feet hip-width apart on the force plate while standing barefoot. They were then asked to lift a box weighing 10% of their body weight from the ground to waist height and then from waist height to overhead with straight elbows. They moved the box at their selected speed. The examinations began upon the examiner's command. Results: Results indicated a significant difference (p&lt;0.001) in all postural control variables in chronic LBP patients who lifted a load at different heights. In addition, there was a significant difference between all of the postural control measures of this study in healthy participants during load lifting at different heights (p&lt;0.05), with the exception of the mediolateral standard deviation of velocity (p=0.067). Conclusion: Different lifting heights impact LBP patients' and healthy people's postural control differently. Postural control was more challenging during waist-to-overhead lifting in the patient group. This may be due to a stiffening strategy. The central nervous system reduces postural sway at higher centers of mass.

Quantifying the weights of sensory influences on postural control across development

BACKGROUND: This study examined the weighting of multisensory and anthropometric factors in driving children’s and adult’s postural control. METHOD: A data set was created by aggregating individual participants’ postural stability measures from four target studies, employing participants ranging in age from 3 to 11 years, along with young adults. Using a meta-regression approach, this aggregate data set was then predicted from dummy codings of the including visual, haptic, and proprioceptive sensory inputs manipulated in these studies, as well as the anthropometric factor of participant height. Two forms of coding regimens were examined – one capturing simple presence versus absence of sensory sources, and one quantifying the degree of stability provided by sensory sources. RESULTS: The results of this study revealed that proprioceptive input had the strongest impact on stability, followed by roughly equivalent visual and haptic inputs, and finally anthropometric factors. Developmentally, this pattern of findings was stable by 5- to 7-years of age. Although both coding schemes predicted posture, the degree of stability coding scheme provided consistently superior predictions. INTERPRETATION: These findings are discussed with respect to a multicomponential approach to postural control, a framework that emphasizes the importance of multiple component factors in characterizing complex behavior.

Ergonomic Workstation Design for Online Shop Live Streamers: Reducing Musculoskeletal Disorders (Pt. Xyz Case Study)

This study was conducted at PT. XYZ to evaluate and reduce the risk of musculoskeletal disorders among host streamers through the design of ergonomic workstations. The research method used was a quantitative case study approach, with the population consisting of employees at PT. XYZ who worked as host streamers. Purposive sampling was employed to select 10 respondents who frequently experienced fatigue and complaints in specific body areas. Primary data were collected through observation, questionnaires, guidelines, and interviews. Posture measurements were taken using the REBA (Rapid Entire Body Assessment) and RULA (Rapid Upper Limb Assessment) methods. The results indicated that prior to the intervention, host streamers had REBA and RULA scores that signified a high risk of musculoskeletal disorders, particularly in the neck, shoulders, back, and legs. After implementing an adjustable live streaming workstation design, along with adjustments to lighting and microphone positions, there was a significant decrease in the REBA and RULA scores. The REBA score decreased from 10 to 1, and the average RULA score dropped from 7 to 3. This indicated a significant reduction in the risk of musculoskeletal disorders. The conclusion of the study was that the design of an adjustable ergonomic workstation significantly reduced the risk of musculoskeletal disorders among host streamers at PT. XYZ, thereby enhancing worker comfort and health during live streaming.

Use of a Microelectromechanical Systems Sensor for Objective Measurements of Abnormal Head Posture in Congenital Superior Oblique Palsy Patients.

The purpose of this study was to design an objective method for measurement of head positions as achieved with use of a microelectromechanical systems (MEMS) sensor. In addition, to use this system to observe the abnormal head position (AHP) in patients with congenital superior oblique palsy (SOP) before and after their surgery. An MEMS sensor was designed for recording of the pitch, roll, and yaw values of the head position in real time. The MEMS sensor was then fixed on the synoptophore from -30 degrees to +30 degrees positions horizontally and vertically to test the accuracy of these measurements. Then, we tested 13 participants with AHP using the MEMS method and the photographic method and compared their correlations. Finally, the pitch, roll, and yaw values of head positions were measured using this MEMS sensor in 31 patients with congenital SOP as performed before and after their surgery. The MEMS sensor (LPMS-B2; Alubi, Guangzhou, China; 400 hertz [Hz]), as based on the theory of a gyroscope, was designed and connected to a smartphone via Bluetooth. It was able to conveniently record the patient's pitch, roll, and yaw head positions in real time, recordings which were consistent with the scales of the synoptophore (P > 0.05) and good correlations with the photographic method (P < 0.001). The main preoperative AHP in patients with SOP was roll (22/31, 71%). Pre- and postoperative vertical deviations were 16.4 ± 7.3 prism diopters (PD) and 4.1 ± 4.2 PD, respectively (P = 0.001). The AHP in patients with SOP was positively correlated with the angle of extorsion in the dominant eye (P = 0.01), rather than that of the vertical deviation. The MEMS sensor described in this report is a simple, practical, and accurate objective device for use in head position measurements. In patients with SOP, the AHP is related to the angle of extorsion in the dominant eye. The MEMS sensor was designed as a micro-wireless dynamic high-precision device for AHP measurement, which has the potential for use in a clinic.

Effects of Armor Design and Marksmanship Posture on Performance, Postural Sway and Perceived Workload During a Military Rifle Marksmanship Task.

This study investigated the effects of mass and vertical center-of-mass position of combat items attached to a tactical vest, as well as marksmanship posture on rifle marksmanship performance, postural sway, and perceived workload during a simulated rifle shooting task. A tactical vest serves as a load carriage system in addition to providing body protection. Its design, particularly the mass and vertical position of attached combat items, may impact postural control during rifle shooting and thus marksmanship performance. Thirty-two participants performed a simulated rifle shooting task on a force plate with a tactical vest on. Three independent variables were considered: load mass (4 levels), vertical load center-of-mass position (4 levels), and marksmanship posture (2 levels). The dependent variables were: 6 rifle marksmanship performance measures, 7 postural sway measures, and a perceived workload measure. Heavier load mass significantly degraded rifle marksmanship performance, and increased postural sway and perceived workload. Marksmanship posture significantly affected rifle marksmanship performance and postural sway. The kneeling posture resulted in less postural sway and better marksmanship performance than the standing posture. Vertical load center-of-mass position affected only part of the marksmanship performance measures and did not affect the measures of postural sway and perceived workload. Reducing combat item mass on tactical vests and enhancing soldier postural control ability would improve rifle marksmanship and soldier lethality. The study findings inform the development of future military tactical vests and rifle marksmanship training, highlighting the need for lightweight gear design and postural control training.

Y-Balance Test after ACL Reconstruction: The relationship with knee and hip muscle strength, ankle dorsiflexion range of motion and postural stability

BackgroundY-Balance Test (YBT) assesses postural stability. When is applied to patients after anterior cruciate ligament reconstruction (ACLR), it is not clear which variables influence its result. ObjectiveTo connect YBT and postural stability, quadriceps, hamstring, and gluteus complex muscle strength, ankle dorsiflexion range of motion (ADFROM). Study designCross-sectional. MethodsFifty-nine participants (52 males and 7 females) with ACLR ≥6 months were evaluated. YBT anterior, posterolateral, posteromedial, and composite, isokinetic peak torque of the knee, strength of the gluteal complex with Hip Stability Isometric Test, ADFROM with Weight-Bearing Lunge Test, postural stability with Stability Index of Biodex Balance System® were applied. ResultsIn the ACLR limb, the multivariate regression linear models pointed out an association between the quadriceps muscle strength and ADFRM with anterior, posteromedial and composite reaches (R2 = 0.30; 0.23; 0.26). Hamstring muscle strength and ADFRM with posterolateral (R2 = 0.13). In the uninjured limb, overall stability index and ADFRM with anterior reach (R2 = 0.25), strength of gluteal complex with posteromedial (R2 = 0.31), hamstring muscle strength, Overall and lateromedial stability indexes with posterolateral (R2 = 0.20), hamstring muscle strength, Overall stability index, ADFRM and strength of gluteal complex with composite (R2 = 0.32). ConclusionsThe quadriceps muscle strength and ADFRM are important variables for YBT performance in the ACLR limb. In the uninjured limb, ADFROM, the strength of the gluteal complex and hamstring, overall and lateromedial stability indexes are associated with YBT performance. We question the utility of the YBT to measure postural stability given the lack of association with other postural stability measures.