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Orthopaedics & Traumatology, Surgery &... Dec 2021The placement of prostheses for a total hip arthroplasty (THA) is essential to limit complications and optimize functional results. In a recent study of more than 100...
INTRODUCTION
The placement of prostheses for a total hip arthroplasty (THA) is essential to limit complications and optimize functional results. In a recent study of more than 100 THA placed through a direct anterior approach using a traction table, we found that the mean anteversion of the cup was greater (30°) than recommended (20°). To explain this phenomenon, we considered that the anterior pelvic plane (APP), defined by the plane passing through the anterior-superior iliac spines and the pubic symphysis, which serves as a landmark for the placement and calculation of the anteversion of the cup, was not horizontal when the patient was lying on the traction table. This concept has not been evaluated so we conducted a prospective study to: 1) measure the position of the pelvis on a traction table; 2) compare to the standing position, 3) assess its impact on the anteversion of the cup.
HYPOTHESIS
The standing pelvic version is identical to the supine pelvic version on the traction table.
MATERIAL AND METHODS
A prospective 3-month monocentric study was conducted. All patients operated on for a THA by a direct anterior approach, on a traction table, were included. The position of the pelvis was assessed by measuring the tilt of the APP on lateral pelvic X-rays, while on the traction table and while standing. The impact of the position of the pelvis on the positioning of the cup, as well as the anteversion, were measured using the EOS imaging system. The anatomic anteversion of the cup was measured in relation to the APP.
RESULTS
Fifty-eight patients were included (32 women, 26 men) with an average age of 67 years. The tilt of the supine APP was 6°±8.3 [range of -10.5 to 31.0] (indicating a retroverted pelvis on the traction table). The difference between the tilt of the standing and lying APP (within 90°) was not significant (standing was on average 4.5° [range of -11.0 to 27.0] versus lying on the table, was on average 6° [range of -10.5 to 31.0] (p=0.75). A strong correlation was observed between the tilt of the supine APP and the anatomic anteversion of the cup (p<0.001). Thus, the more retroverted the pelvis was on the traction table, the lower the anatomic anteversion of the acetabular cup.
CONCLUSION
The supine pelvis on the traction table is not always horizontal and its position on the traction table is similar to its standing position, within 90 degrees. The analysis of the positioning of the preoperative pelvis appears to be essential in the planning of a THA through direct anterior approach using a traction table.
LEVEL OF EVIDENCE
IV; Prospective Cohort Study.
Topics: Acetabulum; Aged; Arthroplasty, Replacement, Hip; Female; Hip Prosthesis; Humans; Male; Pelvis; Prospective Studies; Standing Position; Traction
PubMed: 34563732
DOI: 10.1016/j.otsr.2021.103077 -
PloS One 2021The objective of this study was to compare acute effects of prolonged sitting, prolonged standing and sitting interrupted with regular activity breaks on vascular... (Randomized Controlled Trial)
Randomized Controlled Trial
The effects of prolonged sitting, prolonged standing, and activity breaks on vascular function, and postprandial glucose and insulin responses: A randomised crossover trial.
The objective of this study was to compare acute effects of prolonged sitting, prolonged standing and sitting interrupted with regular activity breaks on vascular function and postprandial glucose metabolism. In a randomized cross-over trial, 18 adults completed: 1. Prolonged Sitting; 2. Prolonged Standing and 3. Sitting with 2-min walking (5 km/h, 10% incline) every 30 min (Regular Activity Breaks). Flow mediated dilation (FMD) was measured in the popliteal artery at baseline and 6 h. Popliteal artery hemodynamics, and postprandial plasma glucose and insulin were measured over 6 h. Neither raw nor allometrically-scaled FMD showed an intervention effect (p = 0.285 and 0.159 respectively). Compared to Prolonged Sitting, Regular Activity Breaks increased blood flow (overall effect of intervention p<0.001; difference = 80%; 95% CI 34 to 125%; p = 0.001) and net shear rate (overall effect of intervention p<0.001; difference = 72%; 95% CI 30 to 114%; p = 0.001) at 60 min. These differences were then maintained for the entire 6 h. Prolonged Standing increased blood flow at 60 min only (overall effect of intervention p<0.001; difference = 62%; 95% CI 28 to 97%; p = 0.001). Regular Activity Breaks decreased insulin incremental area under the curve (iAUC) when compared to both Prolonged Sitting (overall effect of intervention P = 0.001; difference = 28%; 95% CI 14 to 38%; p<0.01) and Prolonged Standing (difference = 19%; 95% CI 4 to 32%, p = 0.015). There was no intervention effect on glucose iAUC or total AUC (p = 0.254 and 0.450, respectively). In normal-weight participants, Regular Activity Breaks induce increases in blood flow, shear stress and improvements in postprandial metabolism that are associated with beneficial adaptations. Physical activity and sedentary behaviour messages should perhaps focus more on the importance of frequent movement rather than simply replacing sitting with standing.
Topics: Adult; Area Under Curve; Arterial Pressure; Blood Glucose; Cross-Over Studies; Exercise; Female; Glucose; Hemodynamics; Humans; Hyperglycemia; Insulin; Insulin, Regular, Human; Male; Postprandial Period; Sedentary Behavior; Sitting Position; Standing Position; Triglycerides; Walking
PubMed: 33395691
DOI: 10.1371/journal.pone.0244841 -
Respiration; International Review of... 2020No clinical studies to date have compared unilateral lung or lobe volumes between the supine and standing positions. (Comparative Study)
Comparative Study
Differences in Lung and Lobe Volumes between Supine and Standing Positions Scanned with Conventional and Newly Developed 320-Detector-Row Upright CT: Intra-Individual Comparison.
BACKGROUND
No clinical studies to date have compared unilateral lung or lobe volumes between the supine and standing positions.
OBJECTIVES
To compare lung/lobe volumes on computed tomography (CT) between these two positions and evaluate the correlation between the total lung volume and total lung capacity (TLC) on pulmonary function tests (PFTs).
METHODS
Thirty-two asymptomatic volunteers underwent both conventional CT (supine position) and upright CT (standing position), during deep inspiration breath-hold, and PFTs on the same day. We measured lung/lobe volumes on CT in each position. Paired t tests were used for statistical analysis.
RESULTS
The volumes of the total lung (10.9% increase), right lung (10.3% increase), right upper lobe (8.6% increase), right lower lobe (14.6% increase), left lung (11.6% increase), left upper lobe (7.1% increase), and left lower lobe (16.0% increase) were significantly greater in the standing position than in the supine position (all p < 0.0001). The right middle lobe volume was similar between the two positions (p = 0.16). Intraclass correlation coefficients for agreement between total lung volumes on CT in the supine/standing positions and the TLC on PFT were 0.891/0.938, respectively.
CONCLUSIONS
While the volumes of the bilateral upper and lower lobes and bilateral lungs were significantly greater in the standing than in the supine position, with lower lobes showing larger changes, the right middle lobe volume did not change significantly between positions. The total lung volume on upright CT in the standing position was more similar to TLC on PFT than that in the supine position.
Topics: Adult; Aged; Female; Healthy Volunteers; Humans; Lung; Male; Middle Aged; Multidetector Computed Tomography; Radiography, Thoracic; Reference Values; Standing Position; Supine Position; Total Lung Capacity
PubMed: 32640453
DOI: 10.1159/000507265 -
Orthopaedic Surgery Aug 2021To investigate the sagittal hip-pelvic kinematics in symptomatic cam-type femoroacetabular impingement (FAI) patients in the process of sitting down and compare their... (Comparative Study)
Comparative Study
OBJECTIVE
To investigate the sagittal hip-pelvic kinematics in symptomatic cam-type femoroacetabular impingement (FAI) patients in the process of sitting down and compare their difference between patients with sitting pain complaint and those without.
METHODS
Twenty-nine symptomatic cam-type FAI patients were recruited from our clinic between May 2018 and October 2018. Patients were categorized into two groups depending on whether they complain of pain in prolonged sitting or not. The pelvic-femoral measurements were assessed with a set of lateral pelvic radiography in sitting and standing respectively. Pelvic incidence (PI), sacral slope (SS), and proximal femoral shaft angle (PFSA) were measured on lateral pelvic radiography, and then pelvic tilting, apparent hip flexion, true hip flexion, and the pelvic-femoral ratio were calculated to investigate the kinematic change from standing to sitting position. Demographic measurements, hip morphology measurements, functional measurements, visual analog scale (VAS), and pelvic-femoral measurements were compared between the two groups.
RESULTS
Thirteen cases without sitting pain complaint and 16 cases with sitting pain complaint were stratified to Group N and Group P respectively. No was significant difference in age, body mass index (BMI), and gender between the two groups. Hip morphology measurements (α angle and lateral center-edge angle) and functional measurements (iHOT-12) showed no significant difference between the two groups. However, the mean VAS of pain while sitting was 0.5 ± 0.4 and 1.6 ± 0.6 in Group N and Group P respectively (P = 0.005). Patients with sitting pain complaint have increased pelvic PI compared to those without (50.1° ± 6.5° and 44.2° ± 7.6°, P = 0. 042). The changes in SS (pelvic tilting) from standing to sitting in Group N was significantly larger than that in Group P (21.8° ± 7.0° and 15.1° ± 6.5°, P = 0.012). Although no significant difference in apparent hip flexion and true hip flexion was found. Patients without sitting pain complaint demonstrated a higher pelvic-femoral ratio (22.8% ± 7.9% and 16.1% ± 7.5%, P = 0.010) compared to those with sitting pain complaint.
CONCLUSION
Sagittal pelvic-femoral kinematics could have an influence on the symptomology of cam-type FAI. The small PI and insufficient sagittal pelvic tilting in the process of sitting down could be related to the complaint of sitting pain in patients with symptomatic cam-type FAI.
Topics: Adult; Biomechanical Phenomena; Female; Femoracetabular Impingement; Humans; Male; Middle Aged; Pain Measurement; Patient Positioning; Pelvic Bones; Radiography; Sitting Position; Standing Position
PubMed: 34411458
DOI: 10.1111/os.13038 -
International Journal of Environmental... Apr 2021Standing desks may reduce sedentary behaviors in college students. Students at one mid-size urban university in the Midwestern United States were randomized into... (Randomized Controlled Trial)
Randomized Controlled Trial
Standing desks may reduce sedentary behaviors in college students. Students at one mid-size urban university in the Midwestern United States were randomized into intervention ( = 21) and control groups ( = 27) to assess standing time when given access to standing desks. The intervention group received visual and oral instructor prompts to stand, while the control received no prompts during a 50 min lecture. All students were provided with adjustable tabletop standing desks. ActivPAL accelerometers measured sitting and standing time. A brief survey assessed student preferences, including facilitators and barriers to standing. Mean standing time was greater in the intervention vs. control group (26 vs. 17 min, = 0.023). Students tended to stand in the corners and edges of the room. Main facilitators for standing included to break up sitting, reduce back pain, and increase attention and focus; main barriers were not wanting to distract others or be the only one standing. In total, 87.5% of intervention group participants found five prompts to stand were adequate. Students increased standing time in class when provided with standing desks and instructor prompts to stand. Findings can inform the layout of classrooms and when and how to promote standing desks during lectures.
Topics: Humans; Midwestern United States; Schools; Standing Position; Students; Time Factors; Universities
PubMed: 33922334
DOI: 10.3390/ijerph18094464 -
PloS One 2021Little is known about the early stage balance changes in PD. Many clinicians assume that there are no postural issues in early PD because of failure to identify them on...
INTRODUCTION
Little is known about the early stage balance changes in PD. Many clinicians assume that there are no postural issues in early PD because of failure to identify them on bedside and clinical testing. Here, we quantify balance changes in early and moderate stage PD and compared these values to healthy controls (HC) using clinical assessments of balance and posturography.
METHODS
We compared 15 HC with 15 early PD (PD-II; Hoehn and Yahr stage II) and 15 moderate PD (PD-III; H&Y stage III). Participants performed various clinical tests of balance and a standing postural task on a force platform. We quantified the spatiotemporal parameters of the center of pressure (COP), the sample entropy and power spectral density (PSD) of the COP.
RESULTS
The PSD of the COP differentiated PD-II from HC from 0-0.5 Hz and PD-II from PD-III from 0.5-1 Hz. Specifically, PD-II and PD-III manifested greater power than HC from 0-0.5 Hz, whereas PD-III exhibited greater power than PD-II and HC from 0.5-1.0 Hz (p<0.05). However, there were no significant differences between PD-II and HC in all clinical tests and in spatiotemporal parameters of the COP (p>0.05). Although the sample entropy was significantly lower in the PD groups (p<0.05), entropy failed to differentiate PD-II from PD-III.
CONCLUSION
The low-frequency modulation of the COP in this small cohort differentiated early PD from HC and from moderate PD. Clinicians should be aware that there are early balance deficits in PD. A larger sample size is needed to confirm these findings.
Topics: Aged; Female; Humans; Male; Middle Aged; Parkinson Disease; Postural Balance; Pressure; Spatio-Temporal Analysis; Standing Position
PubMed: 33434235
DOI: 10.1371/journal.pone.0245353 -
Clinical Orthopaedics and Related... Jan 2022Lumbar-pelvic stiffness and sagittal imbalance have been reported to increase the risk of dislocation and wear after THA. One potential way to approach this concern is...
BACKGROUND
Lumbar-pelvic stiffness and sagittal imbalance have been reported to increase the risk of dislocation and wear after THA. One potential way to approach this concern is by identifying patient-specific safe zones for THA components based on the standing and sitting sagittal pelvic tilt. However, there is no algorithm to integrate the standing and sitting pelvic tilt into the surgical plan of component orientations.
QUESTIONS/PURPOSES
We established a new mathematical algorithm for determining a patient-specific safe zone for THA by integrating the impingement-free ROM requirements of standing and sitting while preventing edge loading while standing. We aimed to determine (1) the accuracy of this new method for predicting the impingement-free ROM for a given component orientation, (2) the sensitivity and specificity of detecting an impingement-free acetabular cup position for standing and sitting, and (3) the influences of key factors including pelvic tilt while standing and pelvic tilt while sitting and implant parameters on patient-specific safe zones.
METHODS
A strategy for calculating the intersection of standing and sitting impingement-free safe zones and the zone of a standing radiographic inclination of ≤ 45° was used to develop patient-specific safe zones. We conducted a computer simulation study including the pelvis and THA prosthesis to answer the three study questions. We enrolled 10 patients who underwent robot-assisted THA for avascular necrosis of the femoral head (mean age 49 ± 19 years; five were women) from October 2019 to December 2019. We used a prosthesis model with a conical stem neck and a non-hooded liner, with the femoral head diameter ranging between 28 mm and 40 mm, and the corresponding head-neck ratio ranging between 2.33 and 3.33. We tested 1680 movements for the accuracy of impingement-free ROM (Question 1), and 80 marginal points and 120 non-marginal points of the comprehensive impingement-free safe zone, which combines the standing and sitting postures (Question 2). For Question 3, we explored the influences of standing and sitting pelvic tilt, femoral head diameter, and ROM criteria on the size of the patient-specific safe zone.
RESULTS
With the simulation method as a reference for detecting impingement, the mean absolute error (arithmetic mean of all the absolute errors) of the calculated impingement-free ROM was 1.4° ± 2.3°, and the limit of agreement of errors was between -3.6° and 3.7°. The sensitivity of detecting a safe cup orientation within the comprehensive impingement-free safe zone for a given ROM criterion was 98.9% (95% CI 93.6% to 99.9%), and specificity was 97.1% (95% CI 91.0% to 99.2%). There were no impingement-free safe zones for 29% (pelvic tilt combinations without an impingement-free safe zone and all tested combinations) and no patient-specific safe zones for 46% (pelvic tilt combinations without a patient-specific safe zone and all tested combinations) of the tested combinations of standing and sitting pelvic tilt. The patient-specific safe zone was sensitive to changes in standing and sitting pelvic tilt, femoral head diameter, stem version, and ROM criteria. Stem anteversions beyond 10° to 20° dramatically reduced the size of the patient-specific safe zone to 0 within a change of 10° to 20°.
CONCLUSION
The patient-specific safe zone algorithm can be an accurate method for determining the optimal orientation for acetabular cups and femoral stems in THA. The patient-specific safe zone is sensitive to changes in standing and sitting pelvic tilt, stem version, ROM criteria, and the femoral head diameter. A narrow zone of 10° to 20° for stem anteversion is recommended to maximize the size of the patient-specific safe zone.
CLINICAL RELEVANCE
This study suggests the potential of a mathematical algorithm to optimize the orientation of THA components and illustrates how key parameters affect the patient-specific safe zone.
Topics: Adult; Algorithms; Arthroplasty, Replacement, Hip; Computer Simulation; Female; Hip Prosthesis; Humans; Male; Middle Aged; Pelvis; Postoperative Complications; Radiography; Range of Motion, Articular; Sitting Position; Standing Position
PubMed: 34495893
DOI: 10.1097/CORR.0000000000001923 -
Journal of Neurophysiology Feb 2020The ability to maintain stable, upright standing in the face of perturbations is a critical component of daily life. A common strategy for resisting perturbations and...
The ability to maintain stable, upright standing in the face of perturbations is a critical component of daily life. A common strategy for resisting perturbations and maintaining stability is muscle coactivation. Although arm muscle coactivation is often used during adaptation of seated reaching movements, little is known about postural muscle activation during concurrent adaptation of arm and standing posture to novel perturbations. In this study we investigate whether coactivation strategies are employed during adaptation of standing postural control, and how these strategies are prioritized for adaptation of standing posture and arm reaching, in two different postural stability conditions. Healthy adults practiced planar reaching movements while grasping the handle of a robotic arm and standing on a force plate; the robotic arm generated a velocity-dependent force field that created novel perturbations in the forward (more stable) or backward (less stable) direction. Surprisingly, the degree of arm and postural adaptation was not influenced by stability, with similar adaptation observed between conditions in the control of both arm movement and standing posture. We found that an early coactivation strategy can be used in postural adaptation, similar to what is observed in adaptation of arm reaching movements. However, the emergence of a coactivation strategy was dependent on perturbation direction. Despite similar adaptation in both directions, postural coactivation was largely specific to forward perturbations. Backward perturbations led to less coactivation and less modulation of postural muscle activity. These findings provide insight into how postural stability can affect prioritization of postural control objectives and movement adaptation strategies. Muscle coactivation is a key strategy for modulating movement stability; this is centrally important in the control of standing posture. Our study investigates the little-known role of coactivation in adaptation of whole body standing postural control. We demonstrate that an early coactivation strategy can be used in postural adaptation, but muscle activation strategies may differ depending on postural stability conditions.
Topics: Adaptation, Physiological; Adult; Anticipation, Psychological; Arm; Biomechanical Phenomena; Female; Humans; Male; Motor Activity; Postural Balance; Psychomotor Performance; Standing Position; Young Adult
PubMed: 31851559
DOI: 10.1152/jn.00939.2017 -
Gait & Posture Mar 2024Standing at height, and subsequent changes in emotional state (e.g., fear of falling), lead to robust alterations in balance in adults. However, little is known about...
BACKGROUND
Standing at height, and subsequent changes in emotional state (e.g., fear of falling), lead to robust alterations in balance in adults. However, little is known about how height-induced postural threat affects balance performance in children. Children may lack the cognitive capability necessary to inhibit the processing of threat and fear-related stimuli, and as a result, may show more marked (and perhaps detrimental) changes in postural control compared to adults. This work explored the emotional and balance responses to standing at height in children, and compared responses to young and older adults.
METHODS
Children (age: 9.7 ± 0.8 years, n = 38), young adults (age: 21.8 ± 4.0 years, n = 45) and older adults (age: 73.3 ± 5.0 years, n = 15) stood in bipedal stance in two conditions: at ground level and 80 cm above ground. Centre of pressure (COP) amplitude (RMS), frequency (MPF) and complexity (sample entropy) were calculated to infer postural performance and strategy. Emotional responses were quantified by assessing balance confidence, fear of falling and perceived instability.
RESULTS
Young and older adults demonstrated a postural adaptation characterised by increased frequency and decreased amplitude of the COP, in conjunction with increased COP complexity (sample entropy). In contrast, children demonstrated opposite patterns of changes: they exhibited an increase in COP amplitude and decrease in both frequency and complexity when standing at height.
SIGNIFICANCE
Children and adults adopted different postural control strategies when standing at height. Whilst young and older adults exhibited a potentially protective "stiffening" response to a height-induced threat, children demonstrated a potentially maladaptive and ineffective postural adaptation strategy. These observations expand upon existing postural threat related research in adults, providing important new insight into understanding how children respond to standing in a hazardous situation.
Topics: Young Adult; Child; Humans; Aged; Adolescent; Adult; Fear; Longevity; Standing Position; Postural Balance
PubMed: 38364509
DOI: 10.1016/j.gaitpost.2024.01.032 -
PloS One 2023Recent research in rodents and humans revealed that Whole-Body Vibration (WBV) is beneficial for cognitive functions. However, the optimal WBV conditions are not...
Recent research in rodents and humans revealed that Whole-Body Vibration (WBV) is beneficial for cognitive functions. However, the optimal WBV conditions are not established: contrary to vertical WBV, side-alternating WBV was not investigated before. The present study investigated the short-term effects of side-alternating WBV in standing and sitting posture on specific cognitive function of young adults. We used a balanced cross-over design. Sixty healthy young adults (mean age 21.7 ± 2.0 years, 72% female) participated. They were exposed to three bouts of two-minute side-alternating WBV (frequency 27 Hz) and three control conditions in two different sessions. In one session a sitting posture was used and in the other session a standing (semi-squat) posture. After each condition selective attention and inhibition was measured with the incongruent condition of the Stroop Color-Word Interference Test. WBV significantly (p = 0.026) improved selective attention and inhibition in the sitting posture, but not in the standing posture. The sitting posture was perceived as more comfortable, joyous and less exhaustive as compared to the standing posture. This study demonstrated that side-alternating WBV in sitting posture improves selective attention and inhibition in healthy young adults. This indicates that posture moderates the cognitive effect of WBV, although the effects are still small. Future studies should focus on the working mechanisms and further optimization of settings, especially in individuals who are unable to perform active exercise.
Topics: Female; Humans; Male; Young Adult; Attention; Cognition; Sitting Position; Vibration; Cross-Over Studies; Treatment Outcome; Standing Position
PubMed: 36634088
DOI: 10.1371/journal.pone.0280063