Postural Fatigue Research Articles

Glasses-free Three Dimensional Endoscopic Display System with Multi-face Detection

The glasses-free three dimensional(3D) endoscopic display system provides the surgeon with the depth information of the minimally invasive surgery scene obtained from the binocular perspective, which can effectively relieve the surgeon's posture fatigue and visual fatigue during the long-term surgery, and assist in the operation of surgical instruments more accurately to reduce the damage to the surrounding tissues of the operation area. However, the glasses-free 3D display device currently has the problem of a narrow optimal viewing zone and easy crosstalk, especially in the surgical teaching application scenario, which performs poorly. In order to overcome the limitation of the narrower field of view, we introduce deep learning algorithms to detect and locate multiple faces, fine-tune the 3D display grating of the endoscope, rearrange pixels, and change the best view area, so that more people can get the best view. The experimental results show that the face detection accuracy of the method is 97.88%, and the detection time is 135 frames/ms, which achieves high accuracy while maintaining real-time performance.

Analysis of the Range of Motion and Postural Fatigue in Older Adults During Use Behavior of the Hanging Cabinet

Analysis of the Range of Motion and Postural Fatigue in Older Adults During Use Behavior of the Hanging Cabinet

Time-of-day effects on the postural control and symptoms in women with rheumatoid arthritis

ABSTRACT The present study was designed to assess time-of-day effects on postural balance and symptoms of rheumatoid arthritis (RA) patients. A total of 15 American College of Rheumatology functional class I and II RA patients and 15 healthy controls aged between 45 and 55 (mean age: 50 ± 3) years of age voluntarily participated. We conducted a case-control, repeated-measures in design study. Postural balance, axillary temperature, pain intensity, fatigue, and sleepiness were measured during five test sessions at 06:00, 10:00, 14:00, 18:00, and 22:00 h. Participants were randomized to the order of test sessions, and each session was separated by >36 hours to minimize/eliminate learning effects. Center of pressure area (CoParea) (p < .001), pain (p < .01), and sleepiness (p < .05) values were significantly higher at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. Fatigue significantly increased (p < .05) at 22:00 h in comparison to 10:00, 14:00, and 18:00 h in the RA group. Axillary temperature was significantly (p < .001) lower at 06:00 and at 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. In the control group, there were no significant time-of-day difference in fatigue, but axillary temperature was significantly lower (p < .01) at 06:00 h compared to 10:00 h, 14:00, 18:00, and 22:00 h, sleepiness values were significantly higher (p < .05) at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h, and revealed CoParea values were significantly (p < .05) higher at 06:00 h compared to 14:00 h. Finally, in the RA group, significant correlations were found between values of CoParea and pain (r = 0.47; p < .001), sleepiness (r = 0.39; p < .01), fatigue (r = −0.46; p < .001), and also axillary temperature (r = −0.35; p < .001). Multiple linear regression analysis further indicated that in the RA group, time-of-day variation in postural balance was predicted collectively by that in pain and fatigue (30.7%) (R2 = 0.307; F = 11.53; p < .001). Our results first suggest that time-of-day significantly affects postural balance, axillary temperature, pain intensity, fatigue, and sleepiness in RA patients and second that the temporal variation observed in pain, fatigue, and somnolence are concomitant with that observed in postural balance. Abbreviations: RA: Rheumatoid arthritis; H&O questionnaire: Horne and Ostberg questionnaire; PSQI: Pittsburgh sleep quality index; HAQ: Health assessment questionnaire; SF-36: the short form-36; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; CoP: The Center of foot Pressure; CoParea: The Center of foot Pressure area; VAS: The Visual Analogue Scale; KSS: Karolinska Sleepiness Scale

O17 Physiotherapy experience of treating patients with PIMS-TR COVID-19 following stepdown from PICU

O17 Physiotherapy experience of treating patients with PIMS-TR COVID-19 following stepdown from PICU

The Comparison of Risk Factors Caused by Musculoskeletal Disorders in Female Assembly Workers utilizing MFA and NERPA Methods

Background: Occupational injuries and work-related disabilities are among the most factors contributing to the creation of musculoskeletal disorders (MSDs) in industry. Improper workstation and poor posture increase fatigue load and, eventually, the appearance of MSDs. In addition to reducing physical strength, MSDs mitigate accuracy, augment the accidents, and reduce job productivity. Hence, the purpose of this research was to assess the risk factors for MSDs in electrical devices assembly workers utilizing Muscle Fatigue Assessment (MFA) and Novel Ergonomic Pos­tural Assessment (NERPA). Methods: This study was one cross-sectional descriptive study in the year … and was conducted in one electrical device manufacturing workshop in Khuzestan province along with 84 female workers. 13 jobs and 32 postures were selected in this workshop. Nordic Questionnaire was used to determine the frequency of MSDs. Then, the risk levels were specified in the studied individuals with the use of MFA and NERPA. The obtained data were analyzed in SPSS software version 16. The statistical methods applied in this study were mean, standard deviation, frequency, frequency percentage, t-test of two independent samples, and correlation coefficient assessment. Furthermore, the significance level of statistical tests was considered to be P&lt;0.05. Results: Findings obtained from MFA exhibited that the right wrist and waist were with 66.7%, neck and right shoulder were with 60% of workers and NERPA method results mentioned that the right wrist with 67.3% and the waist with 65.4% and neck with 61.3% and the right shoulder with 60.8% were at “very high” level of corrective actions priority, which these actions must be taken immediately. Also, statistical results indicated that there was a significant correlation between the results of Nordic, MFA, and NERPA questionnaires (P&lt;0.05). Conclusion: Concerning the kind of activity and misuse of support, the highest percentage of risk was evident in the right wrist, waist, and neck. So, a proper design of workstation and implementation of managerial actions were proposed to minimize muscle fatigue. These two methods also had similarities. MFA method was preferred when it was required to assess all body parts. On the other hand, NERPA was applied to determine more details.

Rehabilitation to improve gaze and postural stability in people with multiple sclerosis: study protocol for a prospective randomized clinical trial

BackgroundThe use of vestibular rehabilitation principles in the management of gaze and postural stability impairments in people with multiple sclerosis (PwMS) has shown promise in pilot work completed in our lab and in a recently published randomized clinical trial (RCT). However, further work is needed to fully quantify the gaze and postural impairments present in people with multiple sclerosis and how they respond to rehabilitation.Methods/designThe study is a single blind RCT designed to examine the benefit of a gaze and postural stability (GPS) intervention program compared to a standard of care (SOC) rehabilitation program in dizzy and balance impaired PwMS. Outcomes will be collected across the domains of body structure and function, activity, and participation as classified by the World Health Organization International Classification of Functioning, Disability, and Health (ICF). Our primary outcomes are the Dizziness Handicap Inventory (DHI) and the Functional Gait Assessment (FGA). Secondary outcomes include other measures of gaze and postural stability, fatigue, and functional mobility. Participants who are interested and eligible for enrollment will be consented prior to completing a baseline assessment. Following the baseline assessment each participant will be randomized to either the GPS or SOC intervention group and will complete a 6 week treatment period. During the treatment period, both groups will participate in guided exercise 3x/week. Following the treatment period participants will be asked to return for a post-treatment evaluation and again for a follow-up assessment 1 month later. We anticipate enrolling 50 participants.DiscussionThis study will be an innovative RCT that will utilize gaze and postural stability metrics to assess the efficacy of vestibular rehabilitation in PwMS. It will build on previous work by examining measures across the ICF and improve the current evidence base for treating PwMS.Trial registrationClinicalTrials.gov, May 29th 2018, NCT03521557.

Flexed Posture in Parkinson Disease: Associations With Nonmotor Impairments and Activity Limitations.

People with Parkinson disease (PD) are twice as likely to develop flexed truncal posture as the general older population. Little is known about the mechanisms responsible beyond associations with age, axial motor impairments, and disease severity. The objective was to explore: (1) the associations of the nonmotor impairments of PD with flexed posture, and (2) the relationships of flexed posture with activity limitations. This was a cross-sectional study. Seventy people with PD participated. Posture was measured in standing as the distance between the seventh cervical vertebra and a wall. Nonmotor impairments (cognition, depression, pain, fatigue, and proprioception) and activity performance (upper limb activity, bed transfers, respiratory function, and speech volume) were variously assessed using objective measures and self-report questionnaires. Univariate and multivariate regression analyses were performed to ascertain relationships between nonmotor impairments and truncal posture, and between truncal posture and activities. Greater disease severity, greater axial impairment, poorer spinal proprioception, greater postural fatigue, and male sex were significantly associated with flexed truncal posture. The multivariate model containing these factors in addition to age explained 30% of the variability in flexed truncal posture, with male sex and axial motor impairment continuing to make independent contributions. A significant association was found between greater flexed truncal posture and poorer upper limb activity performance and respiratory function. A limitation to this study was that participants had mild-to-moderate disease severity. Spinal proprioception and postural fatigue were the only nonmotor impairments to make significant contributions to flexed posture. Given the negative influence of flexed posture on upper limb activity and respiratory function, interventions targeting spinal proprioception and postural awareness should be considered for people with PD who might develop flexed posture.

Postural Control Complexity and Fatigue in Minimally Affected Individuals with Multiple Sclerosis

This study investigated changes in postural control complexity in people with multiple sclerosis (PwMS) before and after a fatigue protocol. Thirteen minimally affected PwMS (1.53 ± 1.03- Expanded Disability Status Scale) and 12 non-MS controls. Postural test included quiet stance on a force platform under two visual conditions (saccades and fixation) before and after a fatigue protocol. Postural complexity was assessed through the multiscale entropy. A three-way ANOVA showed a main effect of fatigue in the medial-lateral direction (p <0.007), with fatigue protocol reducing postural complexity in both groups. No differences were found between groups or visual conditions. Minimally affected PwMS demonstrated similar postural complexity compared with non-MS controls under both visual tasks and showed similar decrements in postural complexity as a result of fatigue.

Ergonomic intervention in meeting the challenges of elderly drivers: identifying, prioritising and factorising the ergonomic attributes

Better life expectancy has caused a demographic shift worldwide. The number of elder drivers (aged above 65) has increased, who, even with physiological limitations, do not want to give up driving. This has necessitated conscious efforts to be made for analysing their ergonomic needs and challenges. This research was aimed to identify the major ergonomic concern of the aged drivers that will improve their posture, increase attention and decrease fatigue during driving. Their needs were grouped in 10 ergonomic attributes and their voice about each attribute was captured from a consumer survey. Attributes were prioritised and factor analysis was carried out. Three factors were extracted and were named as musculoskeletal factor, safety factor, and man-machine interface factor. This research provides an understanding of the ergonomic needs of the senior drivers, which the car manufacturers and automobile designers may consider during the design phase to make a car ergonomically more compatible.

Changes in Balance Strategy and Neuromuscular Control during a Fatiguing Balance Task-A Study in Perturbed Unilateral Stance.

Fatigue impairs sensorimotor performance, reduces spinal reflexes and affects the interaction of antagonistic muscles in complex motor tasks. Although there is literature dealing with the interference of fatigue and postural control, the interpretation is confounded by the variety of paradigms used to study it. This study aimed to evaluate the effects of postural fatigue on balance control and strategy, as well as on neuromuscular modulation, in response to postural perturbation (PERT) during a fatiguing balance task. A fatigue protocol consisting of continuous exposure to perturbations until exhaustion was executed in 24 subjects. Number of failed attempts, paths of center of pressure displacement (COP), ankle, knee, and hip joint kinematics, electromyographic activity of the soleus (SOL), tibialis anterior (TA), rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gluteus maximus muscles (GM) and spinal excitability of SOL at the peak of the short-latency responses (SLR) were recorded after posterior PERT. The co-contraction index (CCI) was calculated for TA_SOL, VL_BF and RF_GM. (1) The number of failed attempts significantly increased while COP amplitude and velocity, as well as angular excursion at the ankle, knee and hip joints, decreased with fatigue (P < 0.05). (2) Concomitantly, CCI of SOL_TA, VL_BF and RF_GM increased and spinal excitability in SOL declined. (3) Adaptations progressively augmented with progressing exhaustion and occurred in the distal prior to proximal segment. Distinctly deteriorated balance ability was accompanied by a modified neuromuscular control—the increase in co-contraction reflected by simultaneously activated antagonists is accompanied by smaller knee and hip joint excursions, indicating an elevated level of articular stiffness. These changes may be associated with an exaggerated postural rigidity and could have caused the delayed and reduced postural reactions that are reflected in the changes in COP displacement when compensating for sudden PERT. The reduction in spinal excitability may either be caused by fatigue itself or by an increase in reciprocal inhibition due to augmented TA activity.

The influence of a dynamic elastic garment on musculoskeletal and respiratory wellness in computer users

Background. Evidence is growing that computer users are at increased risk of developing musculoskeletal disorders, particularly those involving the upper extremity, with significant financial cost and lost productivity. Objective. The purpose of this study was to determine the short-term effects of wearing a dynamic elastic garment (Posture Shirt; AlignMed, USA) on musculoskeletal wellness and health in the computer workplace. Methods. Ninety-six computer users were evaluated. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was completed. A functional assessment of posture, lung function, and grip strength was performed after wearing the Posture Shirt for 4 weeks. A training log was kept to track usage of the garment, as well as weekly sensations of fatigue, productivity, and energy level. Results. After 4 weeks, there was statistically significant improvement in forward shoulder and head posture, thoracic kyphosis, and grip strength. Improvements in spirometry measures did not meet statistical significance. Postural fatigue and muscular fatigue decreased by 21% and 29%, respectively, and energy level and productivity increased by 20% and 13%, respectively. Conclusion. This prospective study demonstrated positive short-term impact of the Posture Shirt on both subjective and objective measures of posture, lung function, grip strength, fatigue, and productivity.

An investigation of pointing postures in a 3D stereoscopic environment

Many object pointing and selecting techniques for large screens have been proposed in the literature. There is a lack of quantitative evidence suggesting proper pointing postures for interacting with stereoscopic targets in immersive virtual environments. The objective of this study was to explore users' performances and experiences of using different postures while interacting with 3D targets remotely in an immersive stereoscopic environment. Two postures, hand-directed and gaze-directed pointing methods, were compared in order to investigate the postural influences. Two stereo parallaxes, negative and positive parallaxes, were compared for exploring how target depth variances would impact users' performances and experiences. Fifteen participants were recruited to perform two interactive tasks, tapping and tracking tasks, to simulate interaction behaviors in the stereoscopic environment. Hand-directed pointing is suggested for both tapping and tracking tasks due to its significantly better overall performance, less muscle fatigue, and better usability. However, a gaze-directed posture is probably a better alternative than hand-directed pointing for tasks with high accuracy requirements in home–in phases. Additionally, it is easier for users to interact with targets with negative parallax than with targets with positive parallax. Based on the findings of this research, future applications involving different pointing techniques should consider both pointing performances and postural effects as a result of pointing task precision requirements and potential postural fatigue.

P.20.7 Longitudinal neuromuscular responses in mdx mice challenged with or without addition of forced exercise

Duchenne muscular dystrophy (DMD) is a lethal X-linked neuromuscular disease caused by a mutation in the dystrophin gene, and the mdx mouse is the most widely used model of DMD used in preclinical therapeutic screening. Many neuromuscular diseases such as DMD are characterized by an exaggerated exercise-induced fatigue response, disproportionate to activity level, known as fatigability which is observed in both DMD patients and the mdx mouse. As such, we developed a hind limb fatigue challenge (HLFC) test utilizing postural fatigue and identified a robust, early in vivo fatigability phenotype in the mdx mouse. In the HLFC test, subjects are evaluated in a locomotor task, are then forced to stand on their hind limbs for an extended period of time, and are subsequently evaluated in the same locomotor task. Whereas other exercise paradigms such as the running wheel or treadmill can be used to elicit whole body fatigue incorporating a more robust cardiovascular component, the HLFC test isolates the fatigue to the hindlimb muscles, and we observe consistent early differences in fatigability between mdx and control animals. However, as the mdx mouse exhibits substantial muscle regeneration leading to a mild progression of the disease, the extent of muscle pathology in sedentary adult mdx mice is low and running wheel or treadmill exercise are often used to exacerbate myofibre necrosis, biomarkers indicative of muscle damage, and behavioral deficits. Therefore, the current study directly compares cohorts of mice evaluated in the HLFC longitudinally with or without exercise in between HLFC testing ages. Ultimately, our goal is to develop a behavioral battery which will reliably capture neuromuscular deficits and provide for efficient and robust preclinical testing in the mdx mouse model of DMD. The effectiveness of currently used compounds with therapeutic value in DMD patients, such as prednisone, will be screened using the newly established efficacy study platform.

Video-microscopy for use in microsurgical aspects of complex hepatobiliary and pancreatic surgery: a preliminary report

BackgroundThe use of loupe magnification during complex hepatobiliary and pancreatic (HBP) surgery has become routine. Unfortunately, loupe magnification has several disadvantages including limited magnification, a fixed field and non-variable magnification parameters. The aim of this report is to describe a simple system of video-microscopy for use in open surgery as an alternative to loupe magnification. MethodsIn video-microscopy, the operative field is displayed on a TV monitor using a high-definition (HD) camera with a special optic mounted on an adjustable mechanical arm. The set-up and application of this system are described and illustrated using examples drawn from pancreaticoduodenectomy, bile duct repair and liver transplantation. ResultsThis system is easy to use and can provide variable magnification of ×4–12 at a camera distance of 25–35cm from the operative field and a depth of field of 15mm. This system allows the surgeon and assistant to work from a HD TV screen during critical phases of microsurgery. ConclusionsThe system described here provides better magnification than loupe lenses and thus may be beneficial during complex HPB procedures. Other benefits of this system include the fact that its use decreases neck strain and postural fatigue in the surgeon and it can be used as a tool for documentation and teaching.

Worksite-Induced Morbidities among Truck Drivers in the United States

A critical review was conducted of social, psychological, and health science literature on the array of health risks and morbidities of truckers. Multilevel worksite-induced strains (e.g., long work hours and fatigue, shift work and sleep deprivation, postural fatigue and exposure to noise and vibration, sedentary lifestyle and unhealthy diet, exposure to diesel exhaust fumes, and other occupational stressors) were categorized into six primary morbidities for truckers: (1) psychological and psychiatric disorders; (2) detriments resulting from disrupted biological cycles; (3) musculoskeletal disorders; (4) cancer and respiratory morbidities; (5) cardiovascular disease; and (6) risk-laden substance use and sexual practices. Elevated morbidity risks suggest the need for the design and implementation of systematic epidemiological research and environmental interventions in the transport sector.

Worksite-Induced Morbidities Among Truck Drivers in the United States

A critical review was conducted of social, psychological, and health science literature on the array of health risks and morbidities of truckers. Multilevel worksite-induced strains (e.g., long work hours and fatigue, shift work and sleep deprivation, postural fatigue and exposure to noise and vibration, sedentary lifestyle and unhealthy diet, exposure to diesel exhaust fumes, and other occupational stressors) were categorized into six primary morbidities for truckers: (1) psychological and psychiatric disorders; (2) detriments resulting from disrupted biological cycles; (3) musculoskeletal disorders; (4) cancer and respiratory morbidities; (5) cardiovascular disease; and (6) risk-laden substance use and sexual practices. Elevated morbidity risks suggest the need for the design and implementation of systematic epidemiological research and environmental interventions in the transport sector.

Trunk Muscle Training, Posture Fatigue, and Performance in Laparoscopic Surgery

To investigate the effect of trunk muscle endurance training on the perception of back postural fatigue and performance of a laparoscopic task. Thirty-one medical students (28 men and 13 women) with no laparoscopic surgical experience were randomly assigned to either a training group or a control group. Participants in the training group underwent a 6-week, 18-session trunk (abdominal and back muscle) endurance training program, whereas participants in the control group did not. Performance by all participants was assessed on a simulated laparoscopic task under varying conditions of low back postural fatigue, both before and after the training program. Participants in the training group showed significant improvements in trunk endurance after the 6-week, trunk endurance training program (P<0.05), whereas those in the control group did not. The improvements in trunk endurance were accompanied by significantly reduced perceptions of discomfort (P< .001) and fewer errors during performance of the laparoscopic task. (P<0.02), whereas no significant changes occurred for the control group (P>0.05). Increasing trunk endurance can increase postural fatigue and discomfort during simulated laparoscopic tasks, which may assist in the management of errors during laparoscopy.

Postural Contractions and Muscle Fatigue

Postural Contractions and Muscle Fatigue

Effect of an orthotic intervention on sensorimotor integration mechanisms in patients with musculoskeletal disorders

Summary Objective The objective of this research was to determine the effect of an orthotic intervention on the recruitment profiles of the tibial nerve H-reflex response in patients with musculoskeletal disorders during quiet standing as compared to lying prone on a table. The amount of H-reflex inhibition between resting prone and quiet standing assesses the integrity of sensorimotor integration mechanisms. Design Cross-sectional with repeated measures on footwear conditions for patients with musculoskeletal disorders. Single-blind of investigator for footwear conditions. Setting Research Laboratory. Methods The participants were 12 asymptomatic individuals and 11 patients with musculoskeletal disorders. In the prone and standing positions, H/M recruitment profiles were generated with subjects wearing their aerobic shoes. The subjects rested prone on a treatment table with their feet resting on foot plates. During quiet standing trials, subjects balanced equally on both feet while maintaining a relaxed posture and lightly grasping a hand support at hip level to minimize the influence of postural sway and fatigue. The patients were tested with and without their orthotics inserted into their aerobic shoes. The tibial nerve H-reflex methodology was used to record M-wave and H-reflex responses from the gastrocnemius muscle of the right leg. The Hmax/Mmax ratio was calculated from the recruitment profile in each test position. Results The amount of H-reflex inhibition for the prone position to quiet standing did not systematically increase with the orthotic intervention (12.7%) as compared to the patient's normal shoe condition (13.2%). Regardless of footwear condition, the amount of H-reflex inhibition from the prone position to quiet standing was similar to the effect observed in the asymptomatic individuals (13.4%). Among the patients with musculoskeletal disorders, subject-specific variations in the amount of H-reflex inhibition from the prone position to quiet standing were significantly different from zero, between the two footwear conditions (5.7%; t10 = 4.54). Conclusion Altering sensory feedback signals from the plantar surface of the foot with an orthotic intervention modified sensorimotor integration mechanisms in a subject-specific manner. In agreement with biomechanics research and neuromuscular concepts for the benefits of orthotics, sensorimotor integration mechanisms may be different for each subject-shoe-insert condition.

Flight-Related Musculoskeletal Pain and Discomfort in General Aviation Pilots From the United Kingdom and Ireland

Flight-related musculoskeletal pain and discomfort was examined in general aviation pilots to determine its prevalence. The location, frequency, and severity of the pain, as well as the time for pain to onset and subside were recorded. Associations between pain and personal and flight-related characteristics were explored to determine whether any of these factors increased the risk of pain. Participants consisted of 174 pilots from 45 aerodromes around the United Kingdom and Ireland. Pain and discomfort was reported by 53% of the pilots. The most common pain was reported in the lower back, where it occurred daily or at least weekly, and was of mild to moderate intensity. Pain generally onset after 90 min of flying, and had subsided within 12 hr postflight, although the majority of pain had subsided within 60 min. The occurrence of pain and discomfort was positively correlated with both total flight experience and annual flight hours. Most flight-related pain was caused by postural fatigue and static stress, because most pain was mild and transient, subsiding rapidly post- flight, and was unrelated to age. The use of personal lumbar supports is recommended as the most effective short-term solution to reduce back pain and discomfort.