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International Journal of Environmental... Jun 2020Sit-stand workstations have shown to reduce sitting time in office workers on a group level. However, movement behaviour patterns might differ between subgroups of...
Sit-stand workstations have shown to reduce sitting time in office workers on a group level. However, movement behaviour patterns might differ between subgroups of workers. Therefore, the objective of this study was to examine sitting, standing and stepping outcomes between habitual users and non-users of sit-stand workstations. From an international office population based in the Netherlands, 24 users and 25 non-users of sit-stand workstations were included (all had long-term access to these workstations). Using the ActivPAL, sitting, standing and stepping were objectively measured during and outside working hours. Differences in outcomes between users and non-users were analysed using linear regression. During working hours, users sat less (-1.64; 95% IC= -2.27--1.01 hour/8 hour workday) and stood more (1.51; 95% IC= 0.92-2.10 hour/8 hour workday) than non-users. Attenuated but similar differences were also found for total sitting time over the whole week. Furthermore, time in static standing bouts was relatively high for users during working hours (median= 0.56; IQR = 0.19-1.08 hour/8 hour workday). During non-working hours on workdays and during non-working days, no differences were found between users and non-users. During working hours, habitual users of their sit-stand workstation sat substantially less and stood proportionally more than non-users. No differences were observed outside working hours, leading to attenuated but similar differences in total sitting and standing time between users and non-users for total days. This indicated that the users of sit-stand workstations reduced their sitting time at work, but this seemed not to be accompanied by major carry-over or compensatory effects outside working hours.
Topics: Humans; Male; Netherlands; Occupational Health; Posture; Sitting Position; Standing Position; Workplace
PubMed: 32521625
DOI: 10.3390/ijerph17114075 -
PloS One 2022A simple and inexpensive method to evaluate slip resistance that can be readily introduced into the workplace is required. In the present study, we investigated the...
A simple and inexpensive method to evaluate slip resistance that can be readily introduced into the workplace is required. In the present study, we investigated the relationship between a simple sensory evaluation of anti-slipperiness by foot rubbing in standing and sitting positions and the actual friction properties obtained with in situ measurements at slip onset and during sliding. We also verified the possibility of identifying a hazardous area with a high slip-induced fall risk by the sensory evaluation scores. At the foot rubbing tests, more than half of the 15 participants in experiments could adequately perceive the slip resistance using the proposed method without any education on its perception. Furthermore, hazard detection scores, where a friction coefficient of 0.2 was detected as hazardous area, were obtained from optimal cut-off points of receiver operatorating characteristic curves for the participants with friction perception capability. The scores were 28.7, 20.7, 24.7, and 52.3/100 for the slip onset while standing, sliding while standing, slip onset while sitting, and sliding while sitting, respectively. From the viewpoint of hazard detection accuracies, the standing position was a better way than the sitting although limited to participants with the capability of perceiving friction. Based on the analysis of how to apply forces, the participants who showed a small movement of the center of pressure while standing or an increase in the vertical load while sitting had the capability of perceiving friction.
Topics: Foot; Friction; Humans; Lower Extremity; Shoes; Standing Position
PubMed: 36174046
DOI: 10.1371/journal.pone.0275385 -
Journal of Visualized Experiments : JoVE Jul 2021Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired populations. TMS is used...
Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired populations. TMS is used extensively to study motor control and the response to neurorehabilitation of the upper extremities. However, TMS has been less utilized in the study of lower extremity postural and walking-specific motor control. The limited use and the additional methodological challenges of lower extremity TMS assessments have contributed to the lack of consistency in lower extremity TMS procedures within the literature. Inspired by the decreased ability to record lower extremity TMS motor evoked potentials (MEP), this methodological report details steps to enable post-stroke TMS assessments in a standing posture. The standing posture allows for the activation of the neuromuscular system, reflecting a state more akin to the system's state during postural and walking tasks. Using dual-top force plates, we instructed participants to equally distribute their weight between their paretic and non-paretic legs. Visual feedback of the participants' weight distribution was provided. Using image guidance software, we delivered single TMS pulses via a double-cone coil to the participants' lesioned and non-lesioned hemispheres and measured the corticomotor response of the paretic and non-paretic tibialis anterior and soleus muscles. Performing assessments in the standing position increased the TMS response rate and allowed for the use of the lower stimulation intensities compared to the standard sitting/resting position. Utilization of this TMS protocol can provide a common approach to assess the lower extremity corticomotor response post-stroke when the neurorehabilitation of postural and gait impairments are of interest.
Topics: Evoked Potentials, Motor; Humans; Lower Extremity; Motor Cortex; Muscle, Skeletal; Standing Position; Stroke; Transcranial Magnetic Stimulation
PubMed: 34369926
DOI: 10.3791/62601 -
American Journal of Epidemiology Jan 2018While a growing body of research is examining the impacts of prolonged occupational sitting on cardiovascular and other health risk factors, relatively little work has...
While a growing body of research is examining the impacts of prolonged occupational sitting on cardiovascular and other health risk factors, relatively little work has examined the effects of occupational standing. The objectives of this paper were to examine the relationship between occupations that require predominantly sitting and those that require predominantly standing and incident heart disease. A prospective cohort study combining responses to a population health survey with administrative health-care records, linked at the individual level, was conducted in Ontario, Canada. The sample included 7,320 employed labor-market participants (50% male) working 15 hours a week or more and free of heart disease at baseline. Incident heart disease was assessed using administrative records over an approximately 12-year follow-up period (2003-2015). Models adjusted for a wide range of potential confounding factors. Occupations involving predominantly standing were associated with an approximately 2-fold risk of heart disease compared with occupations involving predominantly sitting. This association was robust to adjustment for other health, sociodemographic, and work variables. Cardiovascular risk associated with occupations that involve combinations of sitting, standing, and walking differed for men and women, with these occupations associated with lower cardiovascular risk estimates among men but elevated risk estimates among women.
Topics: Adult; Aged; Female; Health Surveys; Heart Diseases; Humans; Incidence; Logistic Models; Male; Middle Aged; Occupational Diseases; Occupations; Ontario; Prospective Studies; Risk Factors; Sitting Position; Standing Position
PubMed: 29020132
DOI: 10.1093/aje/kwx298 -
Journal of Neurophysiology Jul 2018This study examined the task dependence of sensory inputs on motoneuron excitability by comparing the inhibitory postsynaptic potential (IPSP) evoked by stimulation of...
This study examined the task dependence of sensory inputs on motoneuron excitability by comparing the inhibitory postsynaptic potential (IPSP) evoked by stimulation of the sural nerve between a standing postural task (Free Standing) and a comparable voluntary isometric contraction performed in a supine position (Lying Supine). We hypothesized that there would be a smaller IPSP in standing than in the supine position, based on the task dependence of the ankle plantarflexor activity on the standing task. Ten healthy participants participated in a total of 15 experiments. Single motor unit (MU) firings were recorded with both intramuscular fine-wire electrodes and high-density surface electromyography. Participants maintained the MU discharge at 6-8 Hz in Free Standing or Lying Supine while the right sural nerve was stimulated at random intervals between 1 and 3 s. To evaluate the reflex response, the firing times of the discriminated MUs were used to construct peristimulus time histograms and peristimulus frequencygrams. The sural nerve stimulation resulted in weaker inhibition in Free Standing than in Lying Supine. This finding is discussed in relation to the putative activation of persistent inward currents in standing posture and the task-dependent advantages of overriding inhibitory synaptic inputs to the plantarflexors to maintain the standing posture. NEW & NOTEWORTHY The task-dependent modulation of sensory inputs on motoneuron excitability in standing is not well understood. Evoking an inhibitory postsynaptic potential (IPSP) resulted in a smaller IPSP in gastrocnemius motoneurons in standing than in the supine position. Mildly painful sensory inputs produced weaker motoneuron inhibition in standing, suggesting an imperative to maintain ankle plantarflexion activity for the task of upright stance.
Topics: Adult; Evoked Potentials, Motor; Female; Humans; Inhibitory Postsynaptic Potentials; Lower Extremity; Male; Middle Aged; Motor Neurons; Muscle, Skeletal; Reflex; Standing Position
PubMed: 29617216
DOI: 10.1152/jn.00555.2017 -
International Angiology : a Journal of... Jun 2023Adjustable compression wraps (ACWs) may represent the future of compression for the treatment of the most severe stages of chronic venous diseases and lymphedema. We...
BACKGROUND
Adjustable compression wraps (ACWs) may represent the future of compression for the treatment of the most severe stages of chronic venous diseases and lymphedema. We tested in five healthy subjects: Coolflex® from Sigvaris®; Juzo wrap 6000®, Readywrap® from Lohmann Rauscher®; Juxtafit® and Juxtalite® from Medi®, Compreflex® from Sigvaris®. The objective of this pilot study was to study the stretch, interface pressures, and Static Stiffness Index (SSI) of the six ACWs applied to the leg.
METHODS
The stretch was evaluated by stretching the ACWs to their maximum length. Interface pressure measurements were performed using a PicoPress transducer and a probe placed at point B1. Interface pressures were measured in the supine resting position and in the standing position. We calculated the SSI. We started the measurements at 20 mmHg in the supine position and increased the pressures by 5 mmHg to 5 mmHg.
RESULTS
Coolflex® (inelastic ACW) cannot exceed a maximum pressure of 30 mmHg at rest with a maximum SSI of approximately 30 mmHg. Juzo wrap 6000® (a 50% stretch) and Readywrap® (a 60% stretch) have a profile of stiffness very near one to the other. The optimal stiffness for Juzo is from 16 mmHg to of 30 mmHg for a resting pressure between 25 mmHg and 40 mmHg. For Readywrap, the optimal stiffness is from 17 mmHg to 30 mmHg with a maximum SSI of 35mmHg. The optimal application zone of this wrap at rest is 30 to 45 mmHg. Juxtafit®, Juxtalite® and Compreflex® (respectively 70%, 80%, 124% stretch) can be applied with pressures above 60 mmHg but with maximum SSI of 20 mmHg for Circaid® and>30 mmHg for Compreflex®.
CONCLUSIONS
This pilot study allows us to propose a classification of wraps according to their stretch: inelastic ACW and short or long stretch ACW (50-60% and 70%, 80%, and 124% stretch). Their stretch and stiffness could help to better determine what could be expected of ACWs in clinical practice.
Topics: Humans; Pilot Projects; Compression Bandages; Veins; Standing Position; Pressure; Chronic Disease
PubMed: 36795457
DOI: 10.23736/S0392-9590.23.04957-X -
International Journal of Environmental... Aug 2022This study investigated how sitting and standing working postures affected operation force, upper limb muscle activation, and task performance using different pointing...
This study investigated how sitting and standing working postures affected operation force, upper limb muscle activation, and task performance using different pointing devices. Fifteen male participants completed cursor aiming and dragging tasks using a conventional mouse, a vertical mouse, and a trackball at sitting and standing workstations. A custom-made force plate was used to measure operation forces applied to the pointing devices. Surface electromyography (EMG) was used to capture the activation of the biceps brachii, triceps brachii, deltoid, and trapezius. Task performance was measured by task success rates, and subjective ratings were obtained for the force required for operation, smoothness of operation, accuracy, and local fatigue in the upper limb. We quantified the following significant outcomes: (1) greater operation forces were found when standing; (2) standing reduced EMG amplitudes of the triceps and trapezius muscles for all tasks; (3) during the aiming task, the vertical mouse had greater operation forces; (4) during the dragging task, both the vertical mouse and trackball had greater operation forces; and (5) task success rates differed for pointing devices only when sitting. This study revealed the distinct biomechanical properties of standing working posture and suggested limited beneficial effects of alternative pointing devices in terms of task performance and subjective ratings.
Topics: Computers; Electromyography; Humans; Male; Muscle, Skeletal; Posture; Sitting Position; Standing Position; Work
PubMed: 36011848
DOI: 10.3390/ijerph191610217 -
Orthopaedic Surgery Dec 2022Sitting is a common weight-bearing posture, like standing, but there still lacks enough understanding of sagittal alignment in sitting position for patients after lumbar...
OBJECTIVES
Sitting is a common weight-bearing posture, like standing, but there still lacks enough understanding of sagittal alignment in sitting position for patients after lumbar fusion. This study aimed to investigate the accommodation of fixed spine from standing to sitting position and its influence on unfused segments.
METHODS
Sixty-two patients after lumbar fusion (test group) and 40 healthy volunteers (control group) were recruited in this research. All subjects underwent lateral radiographs of entire spine in the standing and sitting positions. The spinopelvic parameters including sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), and pelvic tilt (PT) were measured. The changes in parameters of patients between two positions were compared with control group, and patients were divided in different groups based on fusion level and their parameters were compared.
RESULTS
When changing from standing to sitting positions, a forward-moving SVA and TPA were observed in both patients and control groups, accompanied by the decrease in LL, TK and increase in PT, but the changes of patients were smaller in TPA, LL, and TK (6.5° ± 7.2° vs 9.7° ± 6.0°, 7.7° ± 8.3° vs 13.6° ± 8.5°, 2.2° ± 6.5° vs 5.4° ± 5.1°, respectively, p < 0.05). Increase of PT in the lumbosacral fixation group was lower than that in the control group (4.4° ± 9.1° vs 8.3° ± 7.1°, p < 0.05). Patients who had adjacent segments degeneration (ASD) showed more kyphosis in unfused lumbar segments than the other patients (16.4° ± 10.7° vs -1.0° ± 4.8°, p < 0.05) from standing to sitting.
CONCLUSIONS
The spine straightens in lumbar and thoracic curve, combined with forward-moving axis and pelvic retroversion when changing to the sitting position. However, these changes are relatively limited in patients after lumbar fusion, so the adjacent unfused lumbar segments compensate to stress during sitting and this may be related to ASD.
Topics: Humans; Spinal Fusion; Lumbar Vertebrae; Sitting Position; Standing Position
PubMed: 36303439
DOI: 10.1111/os.13553 -
International Journal of Environmental... May 2020Maintaining an upright posture while talking or texting on the phone is a frequent dual-task demand. Using a within-subjects design, the aim of the present study was to...
Maintaining an upright posture while talking or texting on the phone is a frequent dual-task demand. Using a within-subjects design, the aim of the present study was to assess the impact of a smartphone conversation or message texting on standing plantar pressure and postural balance performance in healthy young adults. Thirty-five subjects (mean age 21.37 ± 1.11 years) were included in this study. Simultaneous foot plantar pressure and stabilometric analysis were performed using the PoData system, under three conditions: no phone (), talking on a smartphone () and texting and sending a text message via a smartphone (). Stabilometric parameters (center of pressure (CoP) path length, 90% confidence area and maximum CoP speed) were significantly affected by the use of different smartphone functions ( < 0.0001). The CoP path length and maximum CoP speed were significantly higher under the and conditions when compared to the . CoP path length, 90% confidence area and maximum CoP speed were significantly increased in compared to and . Talking on the phone also influenced the weight distribution on the left foot first metatarsal head and heel as compared with message texting. Postural stability in healthy young adults was significantly affected by talking and texting on a smartphone. Talking on the phone proved to be more challenging.
Topics: Female; Head; Humans; Male; Postural Balance; Smartphone; Standing Position; Text Messaging; Young Adult
PubMed: 32397463
DOI: 10.3390/ijerph17093307 -
International Journal of Environmental... Jun 2022The purpose of this secondary analysis was to assess whether students’ use of stand-biased desks during the school day influenced physical activity (PA) and sedentary... (Randomized Controlled Trial)
Randomized Controlled Trial
The purpose of this secondary analysis was to assess whether students’ use of stand-biased desks during the school day influenced physical activity (PA) and sedentary behaviors (SB) during the afterschool period. By using a crossover design consisting of two 9-week intervention periods, 99 participants from grades 3, 4, and 6 were randomly assigned by their teacher to either a traditional (Group 1; sit−stand) or stand-biased (Group 2; stand−sit) desk in the classroom. The desk type then switched between intervention periods. Afterschool PA and SB were measured by accelerometry at baseline (fall) and following both intervention periods at post I (winter) and post II (spring). Independent sample t-tests and mixed-effects modeling were applied at a significance value of p < 0.05 to detect differences between groups. No significant differences in afterschool SB, light-intensity PA (LPA), or moderate- to vigorous-intensity PA (MVPA) were found between groups. There were also no significant two- or three-way interaction effects detected between desk assignment, time, and afterschool SB, LPA, or MVPA. Stand-biased desks in the classroom were not detrimental to children’s afterschool PA and SB.
Topics: Child; Child Behavior; Exercise; Female; Humans; Interior Design and Furnishings; Male; Sedentary Behavior; Sex Factors; Sitting Position; Standing Position
PubMed: 35805342
DOI: 10.3390/ijerph19137689