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The Journal of Arthroplasty Feb 2022Abnormal spinopelvic mobility is identified as a contributing element of total hip arthroplasty (THA) instability. Preoperative identification of THA patients at risk is... (Observational Study)
Observational Study
BACKGROUND
Abnormal spinopelvic mobility is identified as a contributing element of total hip arthroplasty (THA) instability. Preoperative identification of THA patients at risk is still a remaining challenge. We therefore conducted this study to (1) evaluate if preoperative and postoperative spinopelvic mobility differs, (2) determine the interactions between the elements of the spinopelvic complex, and (3) identify preoperative parameters for predicting spinopelvic mobility.
METHODS
A prospective observational study assessing 197 THA patients was conducted with biplanar stereoradiography in standing and relaxed sitting positions preoperatively and postoperatively. Two independent investigators determined spinopelvic mobility based on 2 different classifications (Δ sacral slope [SS] and Δ pelvic tilt [PT]; Δ from standing to sitting; Δ < 10° stiff, Δ ≥ 10°-30° normal, Δ > 30° hypermobile). Multiple regression analysis and receiver operating characteristic analysis were used to identify predictors for postoperative spinopelvic mobility.
RESULTS
Spinopelvic mobility significantly increased after THA based on ΔPT (Pre/Post: 18.5°/22.8°; P < .000) and ΔSS (Pre/Post 17.9°/22.4°; P < .000). A distinct shift in the ratio from stiff (Pre/Post: 24%/9.7%) to hypermobile (Pre/Post: 10.2%/22.1%) mobility postoperatively was observed. Receiver operating characteristic analysis predicted postoperative stiffness using preoperative PT ≥ 13.0° with a sensitivity of 90% and a specificity of 51% and hypermobility with preoperative SS ≥ 35.2° with a sensitivity of 81% and a specificity of 34%. Age at surgery, preoperative PT, and pelvic incidence were independent predictors of spinopelvic mobility (R = 0.24).
CONCLUSION
Definition of preoperative stiffness should be interpreted with caution by arthroplasty surgeons as mobility itself is influenced by THA. For the first time thresholds for standing preoperative parameters for predicting postoperative spinopelvic mobility could be provided. For preoperative standing only lateral assessment could serve as a screening tool for spinopelvic mobility.
Topics: Arthroplasty, Replacement, Hip; Humans; Prospective Studies; Sacrum; Sitting Position; Standing Position
PubMed: 34742872
DOI: 10.1016/j.arth.2021.10.029 -
Experimental Brain Research Jan 2023The literature on postural control highlights that task performance should be worse in challenging dual tasks than in a single task, because the brain has limited...
The literature on postural control highlights that task performance should be worse in challenging dual tasks than in a single task, because the brain has limited attentional resources. Instead, in the context of visual tasks, we assumed that (i) performance in a visual search task should be better when standing than when sitting and (ii) when standing, postural control should be better when searching than performing the control task. 32 and 16 young adults participated in studies 1 and 2, respectively. They performed three visual tasks (searching to locate targets, free-viewing and fixating a stationary cross) displayed in small images (visual angle: 22°) either when standing or when sitting. Task performance, eye, head, upper back, lower back and center of pressure displacements were recorded. In both studies, task performance in searching was as good (and clearly not worse) when standing as when sitting. Sway magnitude was smaller during the search task (vs. other tasks) when standing but not when sitting. Hence, only when standing, postural control was adapted to perform the challenging search task. When exploring images, and especially so in the search task, participants rotated their head instead of their eyes as if they used an eye-centered strategy. Remarkably in Study 2, head rotation was greater when sitting than when standing. Overall, we consider that variability in postural control was not detrimental but instead useful to facilitate visual task performance. When sitting, this variability may be lacking, thus requiring compensatory movements.
Topics: Young Adult; Humans; Standing Position; Posture; Movement; Task Performance and Analysis; Sitting Position; Postural Balance
PubMed: 36416923
DOI: 10.1007/s00221-022-06512-6 -
Experimental Brain Research Jul 2023Older adults adapt the execution of complex motor tasks to use compensatory strategies in the reaching-to-grasping (i.e., prehension) movement. The presence of postural...
Older adults adapt the execution of complex motor tasks to use compensatory strategies in the reaching-to-grasping (i.e., prehension) movement. The presence of postural constraints may exacerbate these compensatory strategies. Therefore, we investigated the reach-to-grasp action with different postural constraints (sitting, standing, and walking) in younger and older people and evaluated the postural stability during the reach-to-grasp action. Thirty individuals (15 younger and 15 older adults) performed the prehension under three postural tasks: sitting, standing, and walking. The reaching movement was slower in the walking task than in the other two postural tasks; however, there was no difference between the age groups. For the grasping action, the older adults presented a larger grip aperture, and the peak grip aperture occurred earlier during hand transportation in sitting and standing tasks. In the standing task, the margin of stability was smaller for older adults. In the walking task, there was no difference between the groups for the margin of stability. Also, prehension during sitting and standing tasks were similar, and both differed from walking across age groups. Finally, older adults reduced their margin of stability compared to younger adults, but only in the standing task. The margin of stability was similar between age groups during the walking task. We concluded that age affected grasping (distal component) but not reaching (proximal component), suggesting that healthy older adults have more difficulty controlling distal than proximal body segments.
Topics: Humans; Aged; Walking; Hand; Movement; Standing Position; Sitting Position; Postural Balance
PubMed: 37256337
DOI: 10.1007/s00221-023-06647-0 -
Perceptual and Motor Skills Dec 2023Mechanical vibration of the Achilles tendon is widely used to analyze the role of proprioception in postural control. The response to this tendon vibration (TV) has been...
Mechanical vibration of the Achilles tendon is widely used to analyze the role of proprioception in postural control. The response to this tendon vibration (TV) has been analyzed in the upright posture, but the feet positions have varied in past research. Moreover, investigators have addressed only temporal parameters of the center of pressure (CoP). We investigated the effect of TV on both temporal and spectral characteristics of the CoP motion. Eighteen healthy young adults, stood barefoot, with one foot on each side of a dual platform, wearing glasses with opaque lenses. We applied 20 seconds of Achilles TV (bilaterally with inertial vibrators at a frequency of 80 Hz and an amplitude of .2-.5 mm). We analyzed CoP signals pre-vibration (PRE,4-seconds), during vibration (VIB,20 seconds), and after vibration cessation (REC,20 seconds). We repeated this protocol in natural and standardized positions (15° feet angular opening). For determining CoP amplitude and velocity, we divided the 20 seconds into five phases of four seconds each and calculated spectral parameters for the whole 20-second signals. There was an adaptation process in the speed of the CoP mediolateral ( < .01) and anteroposterior ( < .01) and in the displacement of the CoP anteroposterior ( < .01), with higher values in the VIB condition. Velocity and displacement decreased progressively in the REC condition. Median and peak frequencies were higher in the VIB condition when compared to the REC condition, but only in the mediolateral direction ( = .01). The standardized foot position led to increased speed in CoP mediolateral, anteroposterior, and mediolateral displacement ( < .01). CoP spectral characteristics were not affected by foot positioning. We concluded that adaptation of CoP motion in the presence of TV and after its cessation are observable both in time and frequency domains. Feet positioning influenced CoP motion in the presence of TV and after its cessation but it did not affect its spectral characteristics.
Topics: Young Adult; Humans; Achilles Tendon; Vibration; Proprioception; Postural Balance; Standing Position
PubMed: 37654231
DOI: 10.1177/00315125231198161 -
Work (Reading, Mass.) 2023Adjustable height sit-stand desks are becoming the norm in many workplaces. It is not known how task type, worker preference, and occupation impact utilization of the...
BACKGROUND
Adjustable height sit-stand desks are becoming the norm in many workplaces. It is not known how task type, worker preference, and occupation impact utilization of the adjustable height feature.
OBJECTIVE
This survey-based study aimed to determine how task type, preference and occupation affect office workers' sitting and standing behaviors at work.
METHODS
Office workers (n = 123) from different occupations completed surveys about actual and preferred positions (sit, stand, either/both) during 39 common tasks from 4 different categories, as well as barriers to use. Each position was analyzed by task type, behavior, and occupation.
RESULTS
There were differences between actual and preferred behavior for each position, with participants sitting more and standing less than preferred across all task categories. There were differences between task categories with participants sitting less for generative and routine, and standing more for communication tasks. The highest rates of either/both responses were for routine tasks. Engineers reported the lowest standing rates, and also indicated standing more than preferred. Information Tech and Engineering had the highest either/both responses. Finance reported the highest sitting rates. Personal, task-based and workplace limitations were cited as barriers to preferred use.
CONCLUSION
Office workers would prefer to stand more at work. Occupation-specific needs and preferences, as well as types of tasks should be considered when providing workplace standing options.
Topics: Humans; Sedentary Behavior; Standing Position; Occupations; Sitting Position; Workplace; Occupational Health
PubMed: 36245351
DOI: 10.3233/WOR-211274 -
Field- and Laboratory-derived Power-Cadence Profiles in World-Class and Elite Track Sprint Cyclists.Journal of Sports Sciences Sep 2023Previous investigations comparing Torque-Cadence (T-C) and Power-Cadence (P-C) profiles derived from seated and standing positions and field and laboratory conditions...
Previous investigations comparing Torque-Cadence (T-C) and Power-Cadence (P-C) profiles derived from seated and standing positions and field and laboratory conditions are not congruent with current methodological recommendations. Consequently, the aim of this investigation was to compare seated and standing T-C and P-C profiles generated from field and laboratory testing. Thirteen world-class and elite track sprint cyclists ( = 7 males, maximal power output (P) = 2112 ± 395 W; = 6 females, P = 1223 ± 102 W) completed two testing sessions in which field- and laboratory-derived T-C and P-C profiles were identified. Standing P-C profiles had significantly ( < 0.05) greater P than seated profiles, however there were no significant differences in optimal cadence (F) between seated and standing positions. P and F were significantly lower in field-derived profiles in both positions compared to laboratory-derived profiles. However, there was no significant difference in the goodness-of-fit (R) of the P-C profiles between laboratory (0.985 ± 0.02) and field-testing (0.982 ± 0.02) in each position. Valid T-C and P-C profiles can be constructed from field and laboratory protocols; however, the mechanical variables derived from the seated and standing and field and laboratory profiles cannot be used interchangeably. Both field and laboratory-derived profiles provide meaningful information and provide complementary insights into cyclists' capacity to produce power output.
Topics: Male; Female; Humans; Exercise Test; Bicycling; Sitting Position; Standing Position; Torque
PubMed: 38049956
DOI: 10.1080/02640414.2023.2288435 -
Medicine Nov 2021It is recommended to use visual laryngoscope for tracheal intubation in a Corona Virus Disease 2019 patient to keep the operator farther from the patient. How the... (Comparative Study)
Comparative Study
It is recommended to use visual laryngoscope for tracheal intubation in a Corona Virus Disease 2019 patient to keep the operator farther from the patient. How the position of the operator affects the distance in this setting is not ascertained. This manikin study compares the distances between the operator and the model and the intubation conditions when the operator is in sitting position and standing position, respectively.Thirty one anesthesiologists with minimum 3-years' work experiences participated in the study. The participant's posture was photographed when he performed tracheal intubation using UE visual laryngoscope in standing and sitting position, respectively. The shortest distance between the model's upper central incisor and operator's face screen (UF), the horizontal distance between the model's upper central incisor and the operator's face screen, the angle between the UF line and the vertical line of the model's upper central incisor were measured. The success rate of intubation, the duration of intubation procedure, the first-attempt success rate, the Cormack-Lehane grade, and operator comfort score were also recorded.When the operator performed the procedure in sitting position, the horizontal distance between the model's upper central incisor and the operator's face screen distance was significantly longer (9.5 [0.0-17.2] vs 24.3 [10.3-33.0], P ≤ .001) and the angle between the UF line and the vertical line of the model's upper central incisor angle was significantly larger (45.2 [16.3-75.5] vs 17.7 [0.0-38.9], P ≤ .001). There was no significant difference in UF distance when the operator changed the position. Cormack-Lehane grade was significantly improved when it was assessed using visual laryngoscope. Cormack-Lehane grade was not significantly different when the operator assessed it in sitting and standing position, respectively. No significant differences were found in the success rate, duration for intubation, first-attempt success rate, and operator comfort score.The operator is kept farther from the patient when he performs intubation procedure in sitting position. Meanwhile, it does not make the procedure more difficult or uncomfortable for the operator, though all the participants prefer to standing position.
Topics: COVID-19; Humans; Intubation, Intratracheal; Laryngoscopes; Laryngoscopy; Male; Manikins; Patient Positioning; Sitting Position; Standing Position
PubMed: 34871215
DOI: 10.1097/MD.0000000000027529 -
Medical Problems of Performing Artists Sep 2023The purpose of this study was to compare the impact of playing brass and wind instruments in seated versus standing positions on cardiovascular parameters in musicians....
OBJECTIVE
The purpose of this study was to compare the impact of playing brass and wind instruments in seated versus standing positions on cardiovascular parameters in musicians. We hypothesized that heart rate (HR) and blood pressure (BP) would be higher while playing compared to resting, and would be higher in standing compared to seated positions.
METHODS
Ten musicians completed two study visits. In both, resting, supine HR and BP were recorded, followed by 30 minutes of playing. In one visit, participants played seated, and in the other, played while standing. The order of these positions was randomized. BP and HR were recorded every 5 minutes during playing.
RESULTS
Systolic BP was not affected by playing (p = 0.09, eta2 = 0.046) or position (p = 0.35, eta2 = 0.024). Diastolic BP increased while playing (p < 0.0001, eta2 = 0.32), but did not differ between positions (p = 0.21, eta2 = 0.03). Mean arterial pressure (MAP) increased while playing (p < 0.0001, eta2 = 0.25), but did not differ between positions (p = 0.68, eta2 = 0.03). There was a significant time X position interaction for HR (p = 0.0001, eta2 = 0.037). Simple main effects analysis revealed that HR was higher while playing in the standing compared to the seated position at all but one time point.
CONCLUSION
Playing brass and wind instruments increases diastolic BP and MAP, regardless of playing position, while playing in the standing position induces a higher HR compared to the seated position.
Topics: Humans; Blood Pressure; Heart Rate; Rest; Music; Posture; Sitting Position; Supine Position; Standing Position
PubMed: 37659059
DOI: 10.21091/mppa.2023.3016 -
Journal of Clinical Sleep Medicine :... May 2021Restless legs syndrome (RLS) is known to be a risk factor for cardiovascular disease. However, there are no electrophysiological biomarkers to assess this risk. This...
STUDY OBJECTIVES
Restless legs syndrome (RLS) is known to be a risk factor for cardiovascular disease. However, there are no electrophysiological biomarkers to assess this risk. This study aimed to evaluate heart rate variability (HRV) and cardiovascular reflexes in the supine and standing positions during wakefulness in patients with RLS.
METHODS
Fourteen drug-naïve patients with RLS (12 women and 2 men, mean age, 42.14 ± 7.81 years) and 10 healthy control patients underwent tests for blood pressure, heart rate when in the supine and standing positions, and deep breathing and handgrip tests in controlled laboratory conditions. Data on 5-minute R-R intervals at each position were collected and analyzed for HRV.
RESULTS
Expected cardiovascular reflexes were within the normal range and were similar between the 2 groups. In HRV analysis, the normalized unit of the low-frequency component and the low-frequency/high-frequency ratio during standing were lower in patients with RLS than in the control patients. The low-frequency/high-frequency ratio responses during the change from the supine to the standing position were significantly reduced in patients with RLS (mean ± standard deviation, 2.94 ± 3.11; control patients: 7.51 ± 5.58; P = .042.) On Spearman rank correlation, questionnaires related to sleep problems were associated with the parameters of HRV.
CONCLUSIONS
Patients with RLS showed reduced sympatho-vagal responses during the change from the supine to the upright position during wakefulness, and RLS-related sleep disturbance was a contributing factor for autonomic nervous system dysfunction. This case-control study showed a difference in HRV response to position change in a considerably small group of patients with RLS. The relevance of this finding is uncertain, but it may be worthy of further investigation in longitudinal studies on RLS and cardiovascular disease.
Topics: Adult; Case-Control Studies; Female; Hand Strength; Humans; Male; Middle Aged; Pharmaceutical Preparations; Restless Legs Syndrome; Standing Position
PubMed: 33438574
DOI: 10.5664/jcsm.9074 -
Veterinary Surgery : VS Jan 2021To determine the variability in length, width, and thickness of the equine linea alba (LA) and the effect of a standing vs dorsal recumbent position on these...
OBJECTIVE
To determine the variability in length, width, and thickness of the equine linea alba (LA) and the effect of a standing vs dorsal recumbent position on these measurements.
STUDY DESIGN
Descriptive anatomical comparative study.
ANIMALS
Standing horses (N = 75; in 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing).
METHODS
Linea alba length was measured in standing position from xiphoid to umbilicus, and transverse ultrasonographic images were obtained at five reference points to measure LA width and thickness. In 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing.
RESULTS
There was wide variation in LA width and thickness between standing horses, with gradual increase from xiphoid (range, 0.14-0.64 cm) to umbilicus (range, 0.2-2.97 cm). Linea alba length in standing position was 51.09 ± 6.219 cm. Width was independent of the size of the horse; thickness and length were correlated at some reference points to height (r = 0.346-585, P < .05) and weight (r = 0.324-0.642, P < .05). Different LA shapes could be identified. In dorsal recumbency, the LA was smaller in width at all reference points (15%-23%, P < .05) and shorter (20%, P < .001) compared with standing.
CONCLUSION
In addition to the wide variability in LA measurements and shapes between horses, there was a significant decrease in LA width and length when horses changed from standing to dorsal recumbency.
CLINICAL SIGNIFICANCE
The difference in LA length and width between dorsal recumbency and when standing could increase tension on sutures after laparotomy and should be taken into account when surgeons are closing the abdomen.
Topics: Abdominal Wall; Animals; Female; Horses; Male; Reference Values; Standing Position
PubMed: 33043994
DOI: 10.1111/vsu.13528