-
Journal of Neurophysiology Aug 2019In addition to being a prerequisite for many activities of daily living, the ability to maintain steady upright standing is a relevant model to study sensorimotor... (Review)
Review
In addition to being a prerequisite for many activities of daily living, the ability to maintain steady upright standing is a relevant model to study sensorimotor integrative function. Upright standing requires managing multimodal sensory inputs to produce finely tuned motor output that can be adjusted to accommodate changes in standing conditions and environment. The sensory information used for postural control mainly arises from the vestibular system of the inner ear, vision, and proprioception. Proprioception (sense of body position and movement) encompasses signals from mechanoreceptors (proprioceptors) located in muscles, tendons, and joint capsules. There is general agreement that proprioception signals from leg muscles provide the primary source of information for postural control. This is because of their exquisite sensitivity to detect body sway during unperturbed upright standing that mainly results from variations in leg muscle length induced by rotations around the ankle joint. However, aging is associated with alterations of muscle spindles and their neural pathways, which induce a decrease in the sensitivity, acuity, and integration of the proprioceptive signal. These alterations promote changes in postural control that reduce its efficiency and thereby may have deleterious consequences for the functional independence of an individual. This narrative review provides an overview of how aging alters the proprioceptive signal from the legs and presents compelling evidence that these changes modify the neural control of upright standing.
Topics: Aging; Humans; Leg; Muscle Spindles; Postural Balance; Proprioception; Standing Position
PubMed: 31166819
DOI: 10.1152/jn.00067.2019 -
International Journal of Environmental... Nov 2021In Japan, standing while working has not yet become commonplace, and there is little evidence to support the benefits of standing during the workday. Therefore, this... (Randomized Controlled Trial)
Randomized Controlled Trial
In Japan, standing while working has not yet become commonplace, and there is little evidence to support the benefits of standing during the workday. Therefore, this study assessed the relationship between the introduction of a sit-stand desk and its ability to reduce the negative effects of sitting too long and increase employees' general health and productivity. Seventy-four Japanese desk workers participated in this three-month intervention study. Using a randomized controlled trial, the participants were divided into intervention ( = 36) and control ( = 38) groups. The participant characteristics were ascertained using a questionnaire. The intervention effectiveness was assessed by measuring health-, physical activity-, and work-related outcomes. The results indicate that the intervention group significantly decreased their sitting time at work ( = 0.002) and had reduced neck and shoulder pain ( = 0.001). There was a significant increase in subjective health ( = 0.002), vitality in work-related engagement ( < 0.001), and self-rated work performance over a four-week period ( = 0.017). These findings indicate a significant difference between the two groups, demonstrating the effectiveness of a sit-stand desk in reducing sedentary behavior and improving workers' health and productivity. Future research can accumulate further evidence of best practice use of sit-stand desks.
Topics: Efficiency; Humans; Occupational Health; Sedentary Behavior; Standing Position; Workplace
PubMed: 34770116
DOI: 10.3390/ijerph182111604 -
The Journal of Spinal Cord Medicine May 2018Impaired balance function after a spinal cord injury (SCI) hinders performance of daily activities.
CONTEXT
Impaired balance function after a spinal cord injury (SCI) hinders performance of daily activities.
OBJECTIVE
To assess the evidence on the effectiveness of task-specific training on sitting and standing function in individuals with SCI across the continuum of care.
METHODS
A systematic search was conducted on literature published to June 2016 using people (acute or chronic SCI), task-specific interventions compared to conventional physical therapy, and outcome (sitting or standing balance function). The PEDro scale was used to investigate the susceptibility to bias and trial quality of the randomized controlled trials (RCTs). A standardized mean difference (SMD) was conducted to investigate the effect size for interventions with sitting or standing balance outcomes.
RESULTS
Nineteen articles were identified; three RCTs, two prospective controlled trials, one cross-over study, nine pre-post studies and four prospective cohort studies. RCT and cross-over studies were rated from 6 to 8 indicating good quality on the PEDro scale. The SMD of task-specific interventions in sitting compared to active and inactive (no training) control groups was -0.09 (95% CI: -0.663 to 0.488) and 0.39 (95% CI: -0.165 to 0.937) respectively, indicating that the addition of task-specific exercises did not affect sit and reach test performance significantly. Similarly, the addition of BWS training did not significantly affect BBS compared to conventional physical therapy -0.36 (95% CI: -0.840 to 0.113). Task-specific interventions reported in uncontrolled trials revealed positive effects on sitting and standing balance function.
CONCLUSION
Few RCT studies provided balance outcomes, and those that were evaluated indicate negligible effect sizes. Given the importance of balance control underpinning all aspects of daily activities, there is a need for further research to evaluate specific features of training interventions to improve both sitting and standing balance function in SCI.
Topics: Adult; Clinical Trials as Topic; Exercise Therapy; Female; Humans; Male; Middle Aged; Neurological Rehabilitation; Postural Balance; Sitting Position; Spinal Cord Injuries; Standing Position
PubMed: 28738740
DOI: 10.1080/10790268.2017.1350340 -
Journal of the American Veterinary... Aug 2022
Topics: Animals; Standing Position
PubMed: 36006911
DOI: 10.2460/javma.260.12.1406 -
Physical Therapy in Sport : Official... May 2021We aimed to assess the test-retest reliability of a supine and standing knee joint position sense (JPS) test, respectively, and whether they discriminate knees with...
OBJECTIVES
We aimed to assess the test-retest reliability of a supine and standing knee joint position sense (JPS) test, respectively, and whether they discriminate knees with anterior cruciate ligament (ACL) injury from asymptomatic knees.
DESIGN
Repeated measures and cross-sectional.
SETTING
Research laboratory.
PARTICIPANTS
For test-retest reliability, 24 persons with asymptomatic knees. For discriminative analysis: 1) ACLR - 18 persons on average 23 months after unilateral ACL reconstruction, 2) CTRL - 23 less-active persons, and 3) ATHL - 21 activity level-matched athletes.
MAIN OUTCOME MEASURES
Absolute error (AE) and variable error (VE).
RESULTS
Test-retest reliability was generally highest for AE of the standing test (ICC 0.64-0.91). Errors were less for the standing compared to the supine test across groups. CTRL had greater knee JPS AE (P = 0.005) and VE (P = 0.040) than ACLR. ACLR knees showed greater VE compared to the contralateral non-injured knees for both tests (P = 0.032), albeit with a small effect size (η = 0.244).
CONCLUSIONS
Our standing test was more reliable and elicited lesser errors than our supine test. Less-active controls, rather than ACLR, produced significantly greater errors. Activity level may be a more predominant factor than ACLR for knee JPS ∼2 years post-reconstruction.
Topics: Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Cross-Sectional Studies; Female; Humans; Knee Joint; Male; Proprioception; Range of Motion, Articular; Reproducibility of Results; Standing Position; Supine Position; Young Adult
PubMed: 33667776
DOI: 10.1016/j.ptsp.2021.02.010 -
Journal of Neuroengineering and... Nov 2022In older adults, the extent to which performing a cognitive task when standing diminishes postural control is predictive of future falls and cognitive decline. The...
BACKGROUND
In older adults, the extent to which performing a cognitive task when standing diminishes postural control is predictive of future falls and cognitive decline. The neurophysiology of such "dual-tasking" and its effect on postural control (i.e., dual-task cost) in older adults are poorly understood. The purpose of this study was to use electroencephalography (EEG) to examine the effects of dual-tasking when standing on brain activity in older adults. We hypothesized that compared to single-task "quiet" standing, dual-task standing would decrease alpha power, which has been linked to decreased motor inhibition, as well as increase the ratio of theta to beta power, which has been linked to increased attentional control.
METHODS
Thirty older adults without overt disease completed four separate visits. Postural sway together with EEG (32-channels) were recorded during trials of standing with and without a concurrent verbalized serial subtraction dual-task. Postural control was measured by average sway area, velocity, and path length. EEG metrics included absolute alpha-, theta-, and beta-band powers as well as theta/beta power ratio, within six demarcated regions-of-interest: the left and right anterior, central, and posterior regions of the brain.
RESULTS
Most EEG metrics demonstrated moderate-to-high between-day test-retest reliability (intra-class correlation coefficients > 0.70). Compared with quiet standing, dual-tasking decreased alpha-band power particularly in the central regions bilaterally (p = 0.002) and increased theta/beta power ratio in the anterior regions bilaterally (p < 0.001). A greater increase in theta/beta ratio from quiet standing to dual-tasking in numerous demarcated brain regions correlated with greater dual-task cost (i.e., absolute increase, indicative of worse performance) to postural sway metrics (r = 0.45-0.56, p < 0.01). Lastly, participants who exhibited greater alpha power during dual-tasking in the anterior-right (r = 0.52, p < 0.01) and central-right (r = 0.48, p < 0.01) regions had greater postural sway velocity during dual-tasking.
CONCLUSION
In healthy older adults, alpha power and theta/beta power ratio change with dual-task standing. The change in theta/beta power ratio in particular may be related to the ability to regulate standing postural control when simultaneously performing unrelated, attention-demanding cognitive tasks. Modulation of brain oscillatory activity might therefore be a novel target to minimize dual-task cost in older adults.
Topics: Humans; Aged; Reproducibility of Results; Postural Balance; Attention; Standing Position; Brain; Cognition
PubMed: 36369027
DOI: 10.1186/s12984-022-01095-3 -
PloS One 2023According to research on the effects of posture on psychological states, high-power poses-with the body spread wide open-lead to high-arousal positive emotions, whereas...
According to research on the effects of posture on psychological states, high-power poses-with the body spread wide open-lead to high-arousal positive emotions, whereas low-power poses-with the body slumped and constricted-lead to low-arousal negative emotions. However, postures that lead to both high-arousal negative and low-arousal positive emotions have not been investigated yet. Although relative comparisons between postures have been made, the positioning of postures on the two-dimensional coordinates created by arousal and valence has not been clarified. Therefore, the purpose of this study was to explore and clarify which postures lead to the four types of emotions: high-arousal negative, high-arousal positive, low-arousal negative, and low-arousal positive. In Experiment 1, 29 participants (13 men and 16 women) adopted 12 sitting postures for 1 minute each. In Experiment 2, 25 participants (13 men and 12 women) adopted six sitting and six standing postures for 1 minute each. Arousal and valence were measured after each posture, and heart rate was measured during posture maintenance. Arousal and valence after adopting the postures were compared with the neutral arousal and valence. As a result, postures leading to high-arousal negative and low-arousal positive emotions were identified. In addition, postures leading to high-arousal positive emotions, which are the high-power poses, were identified. There were no differences in the magnitude of psychological effects between sitting and standing postures.
Topics: Male; Humans; Female; Sitting Position; Emotions; Posture; Standing Position; Arousal
PubMed: 37267405
DOI: 10.1371/journal.pone.0286720 -
Journal of Feline Medicine and Surgery Oct 2022The aim of this study was to determine the feasibility of ultrasonographically measuring the caudal vena cava (CVC) at the subxiphoid view of healthy, lightly sedated... (Observational Study)
Observational Study
OBJECTIVES
The aim of this study was to determine the feasibility of ultrasonographically measuring the caudal vena cava (CVC) at the subxiphoid view of healthy, lightly sedated cats in a standing position and lateral recumbency.
METHODS
This was a prospective, observational, experimental single-centre study. Twenty healthy research-purposed cats were enrolled. Two trained operators scanned each cat in two positions - standing and lateral recumbency - in a randomised order. CVC diameter was measured at the narrowest diameter during inspiration and at the widest diameter during expiration, at two anatomical locations along the CVC - where the CVC crosses the diaphragm (base) and 2 mm caudal to the diaphragm. The CVC collapsibility index (CVC-CI) was calculated for each site. Normalcy was assessed with a Shapiro-Wilk test. A one-way ANOVA with post-hoc Tukey's test was used to compare inspiratory with expiratory values within and between groups. A paired -test compared the CVC-CI between groups ( ⩽0.05 indicated statistical significance). Spearman's correlation and Bland-Altman analysis assessed inter-operator variability.
RESULTS
All ultrasonographic data passed normalcy and were reported as mean ± SD. When compared with each other, inspiratory and expiratory values were statistically different for position, location and operator (all <0.0001). There was no statistically significant difference between lateral recumbency or standing position for inspiratory, expiratory and CVC-CI values. Inter-operator variability was substantial, with operator 2 consistently obtaining smaller measurements than operator 1. The mean CVC-CI in lateral recumbency at the base was 24% for operator 1 and 37% for operator 2. For the same site in standing position, CVC-CI was 27% and 41% for operators 1 and 2, respectively.
CONCLUSIONS AND RELEVANCE
This pilot study demonstrates that it is possible to ultrasonographically measure the CVC diameter in both lateral recumbency and a standing position in healthy, lightly sedated cats. However, measurements obtained are operator dependent with variability between individuals. Further studies are needed to determine if ultrasonographic CVC assessment will prove helpful in estimating intravascular volume status in cats.
Topics: Animals; Cats; Pilot Projects; Prospective Studies; Standing Position; Thorax; Vena Cava, Inferior
PubMed: 34904481
DOI: 10.1177/1098612X211064697 -
International Journal of Environmental... May 2021The aim of the study was to compare the static balance of dancers and non-dancers in a bipedal and unipedal stance. Twenty-three female dancers (mean age: 21.3 ± 1.7)...
The aim of the study was to compare the static balance of dancers and non-dancers in a bipedal and unipedal stance. Twenty-three female dancers (mean age: 21.3 ± 1.7) and 24 age and sex-matched subjects (mean age 22.3 ± 1.0) participated in this study. A force platform was used to assess balance. The tests on the balance platform were performed in several positions with different foot placement, such as normal standing (NS) eyes open and eyes closed positions, semi-tandem position (ST), tandem position (TP), and one-leg standing (1L) eyes open and eyes closed position. Significant differences in balance between the dancers and the control group, especially in the tandem position and one-leg standing position with eyes closed were found. We observed higher results for the velocity of the COP in the frontal plane in the TP with a dominant limb in front ( = 0.04) and higher results for the velocity of the COP in the frontal plane ( = 0.01) and in the sagittal plane ( < 0.01) in the TP with a dominant limb in front in the control group. We also observed significant differences between groups in the mean velocity of COP sway in the sagittal plane in the 1 L position with eyes closed ( = 0.04). We concluded that dancing regularly for several years improves static balance.
Topics: Adult; Dancing; Eye; Female; Foot; Humans; Postural Balance; Standing Position; Young Adult
PubMed: 34064678
DOI: 10.3390/ijerph18105056 -
Journal of Applied Clinical Medical... Dec 2021This study examined the performance of a bladder volume measuring device, the BladderScan (BS) BVI9400. The use of the BS offers the possibility of assessing the bladder...
PURPOSE
This study examined the performance of a bladder volume measuring device, the BladderScan (BS) BVI9400. The use of the BS offers the possibility of assessing the bladder volume before positioning the patient and performing the daily image-guided radiotherapy procedure. Patients often cannot lie down before entering the treatment vault. Therefore, the BS was also assessed in a standing position.
METHODS
The repeatability precision was first evaluated, which is the variability of immediate repeated measures of the BS with same operator and subject. This was followed by the reproducibility precision of the BS in which the operator and subjects differ. Finally, the trueness was evaluated in terms of fixed and proportional bias of the results by applying weighted least-squares fitting. Note that 53 and 85 patient measurements were carried out in supine and standing position, respectively, each consisting of three repeated BS measurements. These were compared with the computed tomography (CT)-delineated bladder volume.
RESULTS
Repeatability was dependent on measurement value (heteroscedasticity) with σ (BS) = ±15 cm ± 10%. However, the total agreement between BS and CT was low with the 95% limits of agreement (LOAs) exceeding ±200 cm due to poor patient reproducibility and presence of fixed and proportional bias. Only in the best case of male patients in the supine position, three BS measurements, and correction for the fixed and proportional bias, 95% LOAs of [-147, +114] cm were obtained between CT and BS.
CONCLUSION
The agreement of the BVI9400 BS with CT was found to be too low for radiotherapy applications.
Topics: Humans; Male; Radiotherapy, Image-Guided; Reproducibility of Results; Standing Position; Supine Position; Ultrasonography; Urinary Bladder
PubMed: 34676959
DOI: 10.1002/acm2.13424