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The Journal of Spinal Cord Medicine Nov 2023Assessed feasibility and potential effectiveness of using a novel robotic upright stand trainer (RobUST) to deliver postural perturbations or provide...
CONTEXT/OBJECTIVE
Assessed feasibility and potential effectiveness of using a novel robotic upright stand trainer (RobUST) to deliver postural perturbations or provide assistance-as-needed at the trunk while individuals with spinal cord injury (SCI) performed stable standing and self-initiated trunk movements. These tasks were assessed with research participants' hands on handlebars for self-balance assistance (hands on) and with hands off (free hands).
DESIGN
Proof of concept study.
PARTICIPANTS
Four individuals with motor complete (n = 3) or incomplete (n = 1) SCI who were not able to achieve independent standing and presented a neurological lesion level ranging from cervical 4 to thoracic 2.
OUTCOME MEASURES
Ground reaction forces, trunk displacement, and electromyography activity of trunk and lower limb muscles.
RESULTS
Research participants received continuous pelvic assistance via RobUST, and manual trainer assistance at the knees to maintain standing. Participants were able to attempt all tasks. Free hands trunk perturbations resulted in greater load bearing-related sensory information (73% ipsilateral vertical loading), trunk displacement (57%), and muscle activation compared to hands on. Similarly, free hands stable standing with RobUST assistance-as-needed resulted in 8.5% larger bodyweight bearing, 112% larger trunk movement velocity, and higher trunk muscles activation compared to standing with hands on. Self-initiated trunk movements controlled by hands on showed 116% greater trunk displacement, 10% greater vertical ground reaction force, and greater ankle muscle activation compared to free hands.
CONCLUSION
RobUST established a safe and challenging standing environment for individuals with SCI and has the potential to improve training paradigms and assessments of standing postural control.
Topics: Humans; Spinal Cord Injuries; Robotic Surgical Procedures; Torso; Standing Position; Muscle, Skeletal; Postural Balance
PubMed: 35532324
DOI: 10.1080/10790268.2022.2069532 -
International Journal of Environmental... Apr 2022Prior investigations have been primarily conducted in a laboratory to examine the effects of the smartphone use on the neck and head positions, whether these results are...
Prior investigations have been primarily conducted in a laboratory to examine the effects of the smartphone use on the neck and head positions, whether these results are applicable to actual conditions is still unknown. This field survey thus analyzed the neck flexion (NF), head flexion (HF), gaze angle (GA), and viewing distance (VD) of smartphone users in public areas in Taipei, Taiwan. Six hundred smartphone users (300 men and 300 women) were photographed sagittally in standing, supported sitting, or unsupported sitting postures while using a smartphone. Results showed that women had significantly less NF and HF and shorter VDs than male users. Regardless of gender, higher NF was observed for standing than for sitting. Women had similar NF and HF while sitting supported and unsupported, but both were significantly lower than those while standing. By contrast, male users had higher NF and HF during unsupported sitting than during supported sitting. The NF (45°-50°) was much greater than the recommended maximum safe NF of 15°. Women may be at higher risk of visual strain because of shorter VD.
Topics: Female; Humans; Male; Neck; Posture; Sitting Position; Smartphone; Standing Position
PubMed: 35457450
DOI: 10.3390/ijerph19084583 -
PloS One 2022Balance can be a main factor contributing to success in many disciplines, and biathlon is a representative example. A more stable posture may be a key factor for...
Balance can be a main factor contributing to success in many disciplines, and biathlon is a representative example. A more stable posture may be a key factor for shooting scores. The center of foot pressure (COP) is commonly recorded when evaluating postural control. As COP measurements are highly irregular and non-stationary, non-linear deterministic methods, such as entropy, are more appropriate for the analysis of COP displacement. The aim of our study was to investigate whether the longitudinal effects of biathlon training can elicit specific changes in postural control. Eight national-level biathletes, 15 non-athletes who prior to the experiment took part in 3 months of shooting training, and 15 non-athletes with no prior rifle shooting experience took part in our study. The data was collected with the use of a force plate. Participants performed three balance tasks in quiet standing, the shooting position (internal focus-participants concentrated on maintaining the correct body position and rifle), and aiming at the target (external focus-participants concentrated on keeping the laser beam centered on the targets). Biathletes obtained significantly lower values of sample entropy compared to the other groups during the shooting and aiming at the target trials (p<0.05). External and internal focuses influenced the process of postural control among participants who had prior rifle shooting experience and the control group; they obtained significantly higher values of sample entropy while shooting and aiming at the target compared to the quiet standing trial (p<0.05). The biathletes obtained significantly lower values of sample entropy in the aiming at the target position compared to the quiet standing trial. Specific balance training is associated with the ability to deal with a more challenging, non-specific task. The biathletes seemed to employ a different motor control strategy than the beginners and control group, creating repeating patterns (more regular signal for COP) to keep one's balance during the shooting and aiming at the target positions.
Topics: Athletes; Firearms; Humans; Postural Balance; Posture; Standing Position
PubMed: 35503761
DOI: 10.1371/journal.pone.0267105 -
Scientific Reports Dec 2022Upright computed tomography (CT) provides physiologically relevant images of daily life postures (sitting and standing). The volume of the human airway in sitting or...
Upright computed tomography (CT) provides physiologically relevant images of daily life postures (sitting and standing). The volume of the human airway in sitting or standing positions remains unclear, and no clinical study to date has compared the inspiratory and expiratory airway volumes and luminal areas among standing, sitting, and supine positions. In this prospective study, 100 asymptomatic volunteers underwent both upright (sitting and standing positions) and conventional (supine position) CT during inspiration and expiration breath-holds and the pulmonary function test (PFT) within 2 h of CT. We compared the inspiratory/expiratory airway volumes and luminal areas on CT among the three positions and evaluated the correlation between airway volumes in each position on CT and PFT measurements. The inspiratory and expiratory airway volumes were significantly higher in the sitting and standing positions than in the supine position (inspiratory, 4.6% and 2.5% increase, respectively; expiratory, 14.9% and 13.4% increase, respectively; all P < 0.001). The inspiratory and expiratory luminal areas of the trachea, bilateral main bronchi, and average third-generation airway were significantly higher in the sitting and standing positions than in the supine position (inspiratory, 4.2‒10.3% increases, all P < 0.001; expiratory, 6.4‒12.8% increases, all P < 0.0001). These results could provide important clues regarding the pathogenesis of orthopnea. Spearman's correlation coefficients between the inspiratory airway volume on CT and forced vital capacity and forced expiratory volume in 1 s on PFT were numerically higher in the standing position than in the supine position (0.673 vs. 0.659 and 0.669 vs. 0.643, respectively); however, no statistically significant differences were found. Thus, the airway volumes on upright and conventional supine CT were moderately correlated with the PFT measurements.
Topics: Humans; Prospective Studies; Standing Position; Exhalation; Tidal Volume; Tomography, X-Ray Computed
PubMed: 36494466
DOI: 10.1038/s41598-022-25865-0 -
Journal of the American Heart... Sep 2023Background There are no recommendations for being seated versus nonseated during ambulatory blood pressure (BP) monitoring (ABPM). The authors examined how recent...
Background There are no recommendations for being seated versus nonseated during ambulatory blood pressure (BP) monitoring (ABPM). The authors examined how recent standing or moving versus sitting affect average daytime BP on ABPM. Methods and Results This analysis used baseline assessments from a clinical trial in desk workers with office systolic BP (SBP) 120 to 159 mm Hg or diastolic BP (DBP) 80 to 99 mm Hg. ABPM was measured every 30 minutes with a SunTech Medical Oscar 2 monitor. Concurrent posture (standing or seated) and moving (steps) were measured via a thigh-worn accelerometer. Linear regression determined within-person BP variability explained () by standing and steps before ABPM readings. Mean daytime BP and the prevalence of mean daytime BP >135/85 mm Hg from readings after sitting (seated) or after recent standing or moving (nonseated) were compared with all readings. Participants (n=266, 59% women; age, 45.2±11.6 years) provided 32.5±3.9 daytime BP readings. Time standing and steps before readings explained variability up to 17% for daytime SBP and 14% for daytime DBP. Using the 5-minute prior interval, seated SBP/DBP was lower (130.8/79.7 mm Hg, <0.001) and nonseated SBP/DBP was higher (137.8/84.3 mm Hg, <0.001) than mean daytime SBP/DBP from all readings (133.9/81.6 mm Hg). The prevalence of mean daytime SBP/DBP ≥135/85 mm Hg also differed: 38.7% from seated readings, 70.3% from nonseated readings, and 52.6% from all readings (<0.05). Conclusions Daytime BP was systematically higher after standing and moving compared with being seated. Individual variation in activity patterns could influence the diagnosis of high BP using daytime BP readings on ABPM.
Topics: Humans; Female; Adult; Middle Aged; Male; Sitting Position; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Standing Position; Posture
PubMed: 37589152
DOI: 10.1161/JAHA.123.029999 -
PeerJ 2023Musculoskeletal disorders (MSDs), especially in the lumbar spine, are a leading concern in occupational health. Work activities associated with excessive exposure are a... (Review)
Review
BACKGROUND
Musculoskeletal disorders (MSDs), especially in the lumbar spine, are a leading concern in occupational health. Work activities associated with excessive exposure are a source of risk for MSDs. The optimal design of workplaces requires changes in both sitting and standing postures. In order to secure such a design scientifically proved quantitative data are needed that would allow for the assessment of differences in spine load due to body posture and/or exerted force. Intradiscal pressure (IP) measurement in the lumbar spine is the most direct method of estimating spinal loads. Hence, this study aims at the quantitative evaluation of differences in lumbar spine load due to body posture and exerted forces, based on IP reported in publications obtained from a comprehensive review of the available literature.
METHODOLOGY
In order to collect data from studies measuring IP in the lumbar spine, three databases were searched. Studies with IP for living adults, measured in various sitting and standing postures, where one of these was standing upright, were included in the analysis. For data to be comparable between studies, the IP for each position was referenced to upright standing. Where different studies presented IP for the same postures, those relative IPs (rIP) were merged. Then, an analysis of the respective outcomes was conducted to find the possible relationship of IPs dependent on a specific posture.
RESULTS
A preliminary analysis of the reviewed papers returned nine items fulfilling the inclusion and exclusion criteria. After merging relative IPs from different studies, rIP for 27 sitting and 26 standing postures was yielded. Some of the data were useful for deriving mathematical equations expressing rIP as a function of back flexion angle and exerted force in the form of a second degree polynomial equation for the standing and sitting positions. The equations showed that for the standing posture, the increase in IP with increasing back flexion angle is steeper when applying an external force than when maintaining body position only. In a sitting position with the back flexed at 20°, adding 10 kg to each hand increases the IP by about 50%. According to the equations developed, for back flexion angles less than 20°, the IP is greater in sitting than in standing. When the angle is greater than 20°, the IP in the sitting position is less than in the standing position at the same angle of back flexion.
CONCLUSIONS
Analysis of the data from the reviewed papers showed that: sitting without support increases IP by about 30% in relation to upright standing; a polynomial of the second degree defines changes in IP as a function of back flexion for for both postures. There are differences in the pattern of changes in IP with a back flexion angle between sitting and standing postures, as back flexion in standing increases IP more than in sitting.
Topics: Adult; Humans; Sitting Position; Standing Position; Posture; Lumbar Vertebrae; Lumbosacral Region; Musculoskeletal Diseases
PubMed: 37872945
DOI: 10.7717/peerj.16176 -
BMC Neurology Oct 2023Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden onset thunderclap headache and multiple segmental reversible cerebral vasoconstrictions...
A case report of reversible cerebral vasoconstriction syndrome with thunderclap headache significantly exacerbated in the supine position and alleviated in the standing position.
BACKGROUND
Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden onset thunderclap headache and multiple segmental reversible cerebral vasoconstrictions that improve within 3 months. The postpartum period is a well-known precipitating factor for the onset of RCVS. Cerebral venous thrombosis (CVT) causes thunderclap headaches in the postpartum period. While headache in CVT is sometimes exacerbated in the supine position, the severity of the headache in RCVS is usually independent of body position. In this study, we report a case of RCVS with thunderclap headache exacerbated in the supine position, and headache attacks that resolved quickly in the standing position during the postpartum period.
CASE PRESENTATION
A 33-year-old woman presented with a sudden increase in blood pressure and thunderclap headache on the fifth postpartum day (day 1: the first sick day). The headache was severe and pulsatile, with onset in the supine position in bed, and peaked at approximately 10 s. It was accompanied by nausea and chills but there were no scintillating scotomas or ophthalmic symptoms. The headache resolved in the standing or sitting position but was exacerbated and became unbearable within a few seconds when the patient was in the supine position. Therefore, she was unable to lie supine at night. Computed tomography angiography (CTA) of the head on day 2 and magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) on day 3 showed no abnormalities. However, considering the possibility of RCVS, verapamil was initiated on day 3. The headache resolved the following day. MRA of the head on day 10 revealed diffuse and segmental stenoses in the bilateral middle and posterior cerebral arteries and basilar artery. Therefore, the patient was diagnosed with RCVS. The headache gradually resolved and disappeared completely on day 42. Cerebral vasoconstriction was also improved on MRA on day 43.
CONCLUSIONS
This postpartum RCVS case was notable for the exacerbation of headaches in the supine position. For the diagnosis of thunderclap headache in the postpartum period, RCVS should be considered in addition to CVT when the patient presents with a headache that is exacerbated in the supine position.
Topics: Female; Humans; Adult; Vasoconstriction; Standing Position; Supine Position; Cerebrovascular Disorders; Vasospasm, Intracranial; Headache Disorders, Primary; Headache
PubMed: 37789263
DOI: 10.1186/s12883-023-03381-6 -
International Journal of Environmental... Feb 2023The changes in lumbar lordosis angle (LL) and sacral slope angle (SS) related to upper limb elevation and thoracic kyphosis angle (TK) in baseball players with...
The changes in lumbar lordosis angle (LL) and sacral slope angle (SS) related to upper limb elevation and thoracic kyphosis angle (TK) in baseball players with spondylolysis remain unclear. Herein, we investigated baseball players with spondylolysis and those without low back pain, comparing LL and SS with upper limb elevation within and between groups and TK between groups. Baseball players with spondylolysis were enrolled as subjects, and baseball players without low back pain were enrolled as controls (n = 8 each). X-rays were obtained in the standing position and with maximal elevation position of the upper limb (elevation position). LL and SS were measured in the standing and elevated positions, and TK was measured in the standing position. LL was significantly larger in individuals with spondylolysis than controls. The SS of the control group was significantly larger in the elevated position than in the standing position, while the SS of the spondylolysis group was not significantly different between positions. SS was significantly larger in the spondylolysis group than in the control group, only in the standing position. Physical therapy for spondylolysis should focus on hyperlordosis alignment in the standing and maximal elevation positions of both upper limbs, sacral hyper-slope alignment in the standing position, and decreased sacral slope motion.
Topics: Humans; Standing Position; Low Back Pain; Baseball; Lordosis; Kyphosis; Spondylolysis; Lumbar Vertebrae
PubMed: 36833924
DOI: 10.3390/ijerph20043231 -
Journal of Physiological Anthropology Mar 2022The lumbar multifidus (LMF) muscle, which is involved in the mechanical stability of the lumbar spine, reportedly undergoes atrophy in patients with low back pain....
BACKGROUND
The lumbar multifidus (LMF) muscle, which is involved in the mechanical stability of the lumbar spine, reportedly undergoes atrophy in patients with low back pain. Preventing or mitigating low back pain requires strengthening the LMF muscle; however, methods for triggering selective and significant contraction of this muscle have not been fully studied. This study aims to clarify how, in the hands-and-knees or standing position, the position of the arm and leg on one side affects the activity of the lumbar erector spinae (LES) and LMF muscles.
METHODS
We recruited nine adult men with no prior history of low back pain. Measurements were taken in four different postures under varying conditions (that is, one arm and one leg were lifted in either the hands-and-knees or standing position,) as follows: (1) shoulder joint flexion and hip joint extension in the hands-and-knees position; (2) 90° shoulder joint abduction and hip joint abduction in the hands-and-knees position; (3) shoulder joint flexion and hip joint extension in the standing position; and (4) 90° shoulder joint abduction and hip joint abduction in the standing position. The 90° shoulder joint abduction involved simultaneous horizontal abduction, while the hip joint abduction involved simultaneous extension. Muscle activity of the LES and LMF in each posture was measured using a surface electromyograph.
RESULTS
Muscle activity of the LMF was significantly higher in 90° shoulder joint abduction and hip joint abduction than in shoulder joint flexion and hip joint extension in both the hands-and-knees and standing positions. The LES muscle showed no significant differences in activity between each posture.
CONCLUSIONS
The results suggest that unilateral 90° shoulder joint abduction and contralateral hip joint abduction in the hands-and-knees and standing positions may produce selective and significant contraction of the LMF muscle.
Topics: Adult; Electromyography; Humans; Leg; Lumbosacral Region; Male; Muscle Contraction; Muscle, Skeletal; Muscles; Paraspinal Muscles; Standing Position
PubMed: 35255996
DOI: 10.1186/s40101-022-00279-z -
European Radiology Jun 2023Upright computed tomography (CT) can detect slight changes particularly in the superior vena cava (SVC) volume in healthy volunteers under the influence of gravity. This...
OBJECTIVES
Upright computed tomography (CT) can detect slight changes particularly in the superior vena cava (SVC) volume in healthy volunteers under the influence of gravity. This study aimed to evaluate whether upright CT-based measurements of the SVC area are useful for assessing mean right atrial pressure (mRAP) in patients with heart failure.
METHODS
We performed CT in both standing and supine positions to evaluate the SVC (directly below the junction of the bilateral brachiocephalic veins) and inferior vena cava (IVC; at the height of the diaphragm) areas and analyzed their relationship with mRAP, measured by right heart catheterization in 23 patients with heart failure.
RESULTS
The median age of enrolled patients was 60 (51-72) years, and 69.6% were male. The median mRAP was 3 (1-7) mmHg. The correlations between the standing position SVC and IVC areas and mRAP were stronger than those in the supine position (SVC, ρ = 0.68, p < 0.001 and ρ = 0.43, p = 0.040; IVC, ρ = 0.57, p = 0.005 and ρ = 0.46, p = 0.026; respectively). Furthermore, the SVC area in the standing position was most accurate in identifying patients with higher mRAP (> 5 mmHg) (SVC standing, area under the receiver operating characteristic curve [AUC] = 0.91, 95% confidence interval [CI], 0.77-1.00; SVC supine, AUC = 0.78, 95% CI, 0.59-0.98; IVC standing, AUC = 0.77, 95% CI, 0.55-0.98; IVC supine, AUC = 0.72, 95% CI, 0.49-0.94). The inter- and intraobserver agreements (evaluated by intraclass correlation coefficients) for all CT measurements were 0.962-0.991.
CONCLUSIONS
Upright CT-based measurement of the SVC area can be useful for non-invasive estimation of mRAP under the influence of gravity in patients with heart failure.
KEY POINTS
• This study showed that the superior vena cava (SVC) area in the standing position was most accurate in identifying patients with heart failure with higher mean right atrial pressure. • Upright computed tomography-based measurements of the SVC area can be a promising non-invasive method for estimating mean right atrial pressure under the influence of gravity in patients with heart failure. • Clinical management of patients with heart failure based on this non-invasive modality may lead to early assessment of conditional changes and reduced hospitalization for exacerbation of heart failure.
Topics: Humans; Male; Middle Aged; Aged; Female; Vena Cava, Superior; Standing Position; Atrial Pressure; Heart Atria; Heart Failure; Tomography, X-Ray Computed; Vena Cava, Inferior
PubMed: 36576542
DOI: 10.1007/s00330-022-09360-8