Muscle synergies for multidirectional isometric force generation during maintenance of upright standing posture.

Muscle synergies are defined as coordinated recruitment of groups of muscles with specific activation balances and time profiles aimed at generating task-specific motor commands. While muscle synergies in postural control have been investigated primarily in reactive balance conditions, the neuromechanical contribution of muscle synergies during voluntary control of upright standing is still unclear. In this study, muscle synergies were investigated during the generation of isometric force at the trunk during the maintenance of standing posture. Participants were asked to maintain the steady-state upright standing posture while pulling forces of different magnitudes were applied at the level at the waist in eight horizontal directions. Muscle synergies were extracted by nonnegative matrix factorization from sixteen lower limb and trunk muscles. An average of 5-6 muscle synergies were sufficient to account for a wide variety of EMG waveforms associated with changes in the magnitude and direction of pulling forces. A cluster analysis partitioned the muscle synergies of the participants into a large group of clusters according to their similarity, indicating the use of a subjective combination of muscles to generate a multidirectional force vector in standing. Furthermore, we found a participant-specific distribution in the values of cosine directional tuning parameters of synergy amplitude coefficients, suggesting the existence of individual neuromechanical strategies to stabilize the whole-body posture. Our findings provide a starting point for the development of novel diagnostic tools to assess muscle coordination in postural control and lay the foundation for potential applications of muscle synergies in rehabilitation.

Exploration of postural effects on the external jugular and diploic venous system using upright computed tomography scanning.

PURPOSE: Few studies have investigated the influence of posture on the external jugular and diploic venous systems in the head and cranial region. In this study, we aimed to investigate the effects of posture on these systems using upright computed tomography (CT) scanning. METHODS: This study retrospectively analysed an upright CT dataset from a previous prospective study. In each patient, the diameters of the vessels in three external jugular tributaries and four diploic veins were measured using CT digital subtraction venography in both supine and sitting positions. RESULTS: Amongst the 20 cases in the original dataset, we eventually investigated 19 cases due to motion artifacts in 1 case. Compared with the supine position, most of the external jugular tributaries collapsed, and the average size significantly decreased in the sitting position (decreased by 22-49% on average). In contrast, most of the diploic veins, except the occipital diploic veins, tended to increase or remain unchanged (increased by 12-101% on average) in size in the sitting position compared with the supine position. However, the changes in the veins associated with this positional shift were not uniform; in approximately 5-30% of the cases, depending on each vein, an opposite trend was observed. CONCLUSION: Compared to the supine position, the contribution of external jugular tributaries to head venous drainage decreased in the sitting position, whilst most diploic veins maintained their contribution. These results could enhance our understanding of the physiology and pathophysiology of the head region in upright and sitting positions.

POP-Q Versus Upright MRI Distance Measurements: A Prospective Study in Patients with POP.

INTRODUCTION AND HYPOTHESIS: The gold standard for quantifying pelvic organ prolapse is the pelvic organ prolapse quantification (POP-Q) system; however, upright magnetic resonance imaging (MRI) is a promising new method. The objective of this study was to determine the correlation between POP-Q and MRI measurements of the bladder and cervix. METHODS: This prospective study included patients with prolapse in whom POP-Q points Aa or Ba and C were measured as standard care. MRI scans were performed in an upright position, and the distances of the lowest points of the bladder and cervix to the Pelvic Inclination Correction System (PICS) were calculated. Correlations between POP-Q and MRI-PICS measurements were determined using the Pearson correlation coefficient for normally distributed data and the Spearman's rank correlation coefficient for non-normally distributed data. RESULTS: A total of 63 patients were suitable for analysis. There was a moderate positive correlation between the POP-Q and MRI-PICS measurements for bladder (r(61) = 0.480, r < 0.001) and uterus (r(61) = 0.527, p < 0.001). Measurement differences between POP-Q and MRI-PICS of the bladder and uterus vary from -3.2 cm to 7.1 cm, and from -2.1 cm to 8.5 cm respectively. In 71.4% of patients more descent was seen on upright MRI than with POP-Q measurement for both bladder and uterus. For patients with similar POP-Q measurements, a high variation in MRI measurements of the bladder and uterus was found. CONCLUSION: Despite a moderate positive correlation, upright MRI shows a larger POP extent in 71.4% of the patients than POP-Q. A high variation in MRI measurements for patients with the same POP-Q measurement was seen.

Verification of acromion marker cluster and scapula spinal marker cluster methods for tracking shoulder kinematics: a comparative study with upright four-dimensional computed tomography.

BACKGROUND: This study validated the accuracy of the acromion marker cluster (AMC) and scapula spinal marker cluster (SSMC) methods compared with upright four-dimensional computed tomography (4DCT) analysis. METHODS: Sixteen shoulders of eight healthy males underwent AMC and SSMC assessments. Active shoulder elevation was tracked using upright 4DCT and optical motion capture system. The scapulothoracic and glenohumeral rotation angles calculated from AMC and SSMC were compared with 4DCT. Additionally, the motion of these marker clusters on the skin with shoulder elevation was evaluated. RESULTS: The average differences between AMC and 4DCT during 10°-140° of humerothoracic elevation were - 2.2° ± 7.5° in scapulothoracic upward rotation, 14.0° ± 7.4° in internal rotation, 6.5° ± 7.5° in posterior tilting, 3.7° ± 8.1° in glenohumeral elevation, - 8.3° ± 10.7° in external rotation, and - 8.6° ± 8.9° in anterior plane of elevation. The difference between AMC and 4DCT was significant at 120° of humerothoracic elevation in scapulothoracic upward rotation, 50° in internal rotation, 90° in posterior tilting, 120° in glenohumeral elevation, 100° in external rotation, and 100° in anterior plane of elevation. However, the average differences between SSMC and 4DCT were - 7.5 ± 7.7° in scapulothoracic upward rotation, 2.0° ± 7.0° in internal rotation, 2.3° ± 7.2° in posterior tilting, 8.8° ± 7.9° in glenohumeral elevation, 2.0° ± 9.1° in external rotation, and 1.9° ± 10.1° in anterior plane of elevation. The difference between SSMC and 4DCT was significant at 50° of humerothoracic elevation in scapulothoracic upward rotation and 60° in glenohumeral elevation, with no significant differences observed in other rotations. Skin motion was significantly smaller in AMC (28.7 ± 4.0 mm) than SSMC (38.6 ± 5.8 mm). Although there was smaller skin motion in AMC, SSMC exhibited smaller differences in scapulothoracic internal rotation, posterior tilting, glenohumeral external rotation, and anterior plane of elevation compared to 4DCT. CONCLUSION: This study demonstrates that AMC is more accurate for assessing scapulothoracic upward rotation and glenohumeral elevation, while SSMC is preferable for evaluating scapulothoracic internal rotation, posterior tilting, glenohumeral external rotation, and anterior plane of elevation, with smaller differences compared to 4DCT.

Calculation method for novel upright CT scanner isodose curves.

PURPOSE: A computational method based on Monte-Carlo calculations is presented and used to calculate isodose curves for a new upright and tilting CT scanner useful for radiation protection purposes. METHODS: The TOPAS code platform with imported CAD files for key components was used to construct a calculation space for the scanner. A sphere of water acts as the patient would by creating scatter out of the bore. Maximum intensity dose maps are calculated for various possible tilt angles to make sure radiation protection for site planning uses the maximum possible dose everywhere. RESULTS: The resulting maximum intensity isodose lines are more rounded than ones for just a single tilt angle and so closer to isotropic. These maximum intensity curves are closer to the isotropic assumption used in CTDI or DLP based methods of site planning and radiation protection. The isodose lines are similar to those of a standard CT scanner, just tilted upwards. There is more metal above the beam that lessens the dose above versus below isocenter. CONCLUSION: Aside from the orientation, this upright scanner is very similar to a typical CT scanner, and nothing different for shielding needs to be done for this new upright tilting CT scanner, because an isotropic scatter source is often assumed for any CT scanner.

Uprighting horizontally impacted third molars by super-elastic nickel-titanium wire in patients with an extracted first molar.

Protracting lower second molars and uprighting horizontally impacted third molars is a significant orthodontic challenge in patients who require the extraction of severely decayed first molars. Here, we describe the use of biomechanics to upright 90°-tilted lower third molars following second molar protraction. Herein, we introduce a technique for uprighting the lower third molars by (1) the placement of superelastic nickel titanium archwires, (2) bonding, and (3) repositioning of a buccal tube in a tilted position to compensate for the efficiency of Ni-Ti (nickel-titanium) wire. The treatment mechanics used for our two cases showed that even severely impacted third molars can be uprighted by routine continuous straight-wire techniques. This technique proved to be a simple, efficient and reliable treatment option for uprighting horizontally impacted third molars.

Rapid Drink Challenge During High-resolution Manometry for Evaluation of Esophageal Emptying in Treated Achalasia.

BACKGROUND & AIMS: Incomplete esophageal emptying is a key variable predicting symptom relapse after achalasia treatment. Although optimally evaluated using the timed barium esophagogram (TBE), incomplete esophageal emptying can also be identified on rapid drink challenge (RDC) performed during high-resolution manometry. METHODS: We evaluated if RDC differentiates complete from incomplete esophageal emptying in treated patients with achalasia, against a TBE gold standard. Unselected treated patients with achalasia with both TBE (200 mL of low-density barium suspension) and RDC (200 mL of water in sitting position) were enrolled in 5 tertiary referral centers. TBE barium column height at 1, 2, and 5 minutes were compared with RDC variables: pressurizations >20 mmHg, maximal RDC pressurization, proportion of RDC time occupied by pressurizations, trans-esophagogastric junction gradient, and integrated relaxation pressure. RESULTS: Of 175 patients recruited (mean age, 59 years; 47% female), 138 (79%) were in clinical remission. Complete TBE emptying occurred in 45.1% at 1 minute, 64.0% at 2 minutes, and 73.1% at 5 minutes. RDC integrated relaxation pressure correlated strongly with TBE column height, and a 10-mmHg threshold discriminated complete from incomplete emptying at all 3 TBE time points with area under receiver operating characteristic curves of 0.85, 0.87, and 0.85, respectively. This threshold had high negative predictive values for complete emptying (88% at 2 minutes, 94% at 5 minutes), and modest positive predictive values for incomplete emptying (77% at 2 minutes, 62% at 5 minutes). CONCLUSIONS: RDC during high-resolution manometry is an effective surrogate for TBE in assessing esophageal emptying in treated patients with achalasia.

Assessment of daily variation in pelvic anatomy in women with and without pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: Symptoms of pelvic organ prolapse (POP) can affect quality of life and are reported to progress during the day, although this was never objectified. The aim of this study is to determine whether the pelvic anatomy changes during the day using upright magnetic resonance imaging (MRI), in POP patients and asymptomatic women. METHODS: In this prospective study 15 POP patients and 45 asymptomatic women were included. Upright MRI scans were obtained three times per day. The distances from the lowest points of the bladder and cervix to a standardized reference (pelvic inclination correction system) line were determined. A principal component analysis was performed on the levator plate (LP) shape. Statistical differences between time points and the groups were determined for the bladder, cervix, and LP shape. RESULTS: For all women a significant decrease in bladder and cervix height of -0.2 cm (p<0.001) was seen between morning/midday and afternoon scans. A significant difference in bladder descent during the day between POP patients and asymptomatic women was found (p=0.004). Individual differences in bladder position in the POP group of up to 2.2 cm between the morning and afternoon scan were reported. There was a significant difference in LP shape (p<0.001) between the groups but there were no significant changes during the day. CONCLUSIONS: This study found no clinically relevant pelvic anatomy changes during the day. Still, on an individual level differences can be large, so repeating clinical examination at the end of the day can be recommended in patients when anamnesis and physical examination do not match.

Fostering childbirth education on upright positions and mobility during labor in nulliparous women.

BACKGROUND: Upright labor positions and movement during labor have a positive effect on childbirth, yet the predominant labor positions are still horizontal. Therefore, it is important to explore how it is possible to improve childbirth education, particularly its instructional design, to strengthen women's self-efficacy toward the use of upright positions and mobility during labor. The aim of the study was to evaluate the impact of an instructional approach based on a cognitive engagement ICAP (Interactive, Constructive, Active, Passive) framework on the development of knowledge, attitudes, and self-efficacy expectations toward upright positions and mobility during labor. METHODS: A prospective quasi-experimental study was conducted among nulliparous women from the ultra-orthodox Jewish community (n = 74). While the control group (n = 34) participated in routine childbirth education, the intervention group (n = 36) learned with childbirth education that included interactive and constructive cognitive engagement activities. Participants in both groups completed a set of questionnaires regarding knowledge, attitudes, and self-efficacy. RESULTS: The post-test analysis revealed that women in the intervention group compared to the control group gained significantly higher knowledge scores (p < 0.05), more positive attitudes (p < 0.001), and stronger self-efficacy expectations toward upright positions and mobility during labor (p < 0.01). CONCLUSIONS: The findings suggest that by fostering women's cognitive engagement levels during childbirth education toward the interactive and constructive modes of the ICAP framework, women's self-efficacy to move during labor and to use upright positions can be induced. These results can serve as a foundation to improve the overall effectiveness of childbirth instruction. TRIAL REGISTRATION: The study was registered retrospectively.

Axial loading during supine MRI for improved assessment of lumbar spine: comparison with standing MRI.

BACKGROUND: There are no studies comparing the morphologic changes of lumbar spines between supine axial-loaded and 90° standing magnetic resonance imaging (MRI) examinations of patients with spinal stenosis. PURPOSE: To determine whether axial-loaded MRI using a compression device demonstrated similar morphology of intervertebral disc, dural sac, and spinal curvature as those detected by 90° standing MRI in individuals with suspected spinal stenosis. MATERIAL AND METHODS: A total of 54 individuals suspected of having spinal stenosis underwent both axial-loaded and standing MRI studies. The outcome measures included seven radiologic parameters of the lumbar spine: measures of the intervertebral disc (i.e. cross-sectional area [DA], disc height [DH], and anteroposterior distance [DAP]), dural sac (cross-sectional area [DCSA]), spinal curvature (i.e. lumbar lordosis [LL] and L1-L3-L5 angle [LA]), and total lumbar spine height (LH). RESULTS: For agreement between the two methods, intraclass correlation coefficient (ICC) ≥ 0.8 was found for all seven radiologic parameters. Supine axial-loaded MRI underestimated LL but remained correlated (ICC = 0.83) with standing MRI. Minor differences between the two methods (≤5.0%) were observed in DA, DCSA, DAP, LA, and LH, while a major difference was observed in LL (8.1%). CONCLUSION: Using a compression device with the conventional supine MRI to simulate weight-bearing on the lumbar spine generated MRI morphology, which was strongly correlated with those from a standing MRI.

Changes in the lumbar intervertebral foramen between supine and standing posture in patients with adult spinal deformity: a study with upright computed tomography.

OBJECTIVE: To quantitatively assess the impact of supine and standing positions on the morphological changes in the lumbar intervertebral foramen (LIF) in patients with adult spinal deformity (ASD) using upright CT and conventional supine CT. MATERIALS AND METHODS: Thirty patients with ASD were prospectively enrolled in this study. All subjects underwent standing whole spine posterior/anterior radiographs, lateral radiographs, and whole spine CT, both in the supine and upright standing positions. Two orthopedic surgeons independently measured nine radiographic parameters in the radiograph and the lumbar foraminal area (FA) and height (FH) in supine and upright CT. Statistical analyses were performed to evaluate the risk of LIF decrease when standing upright compared to the supine position. The chi-squared, t test, Pearson's coefficients, intra- and inter-rater reliabilities, and ROC curves were calculated. The level of significance was set at p < 0.05. RESULTS: Among the 300 LIFs, both the lumbar FA and FH were either increased or decreased by > 5% in approximately 30% of LIFs each. The FA decreased in the lower lumbar spine. The concave side had a significantly higher rate of decreased FA and FH than the convex side (p < 0.05 and < 0.05, respectively). ROC analysis showed that narrowing of the intervertebral disc (cutoff > 0.05°) is a risk factor for decreased FA and FH. CONCLUSIONS: This study describes the details of the changes in the neuroforamen using a novel upright CT. In patients with ASD, approximately 30% of LIFs either increased or decreased in size by > 5% when standing. The risk factors for LIF decrease are the lower lumbar spine, concave side, and narrow side of the disc wedge.

The use of image synthesis techniques in target and roi delineation in the upright position.

The use of multi-modality imaging technologies such as CT, MRI, and PET imaging is state of the art for radiation therapy treatment planning. Except for a limited number of low magnetic field MR scanners the majority of such imaging technologies can only image the patient in a recumbent position. Delivering radiation therapy treatments with the patient in an upright orientation has many benefits and several companies are now developing upright patient positioners combined with upright diagnostic helical CT scanners to facilitate upright radiation therapy treatments. Due to the directional changes in the gravitational forces on the patient's body, most structures and organs will change position and shape between the recumbent and upright positions. Detailed knowledge about such structures and organs are therefore often only available in the recumbent position. The problem statement is therefore well defined, that is, how do we know where such structures and organs, that is, the target or region at risk volumes, are in the upright position if those cannot be identified and or delineated accurately enough using the upright diagnostic quality CT images only? This paper outlines two methods based on synthetic CT or MR images to overcome this problem.

Anatomical changes in the male pelvis between the supine and upright positions-A feasibility study for prostate treatments in the upright position.

Treating and imaging patients in the upright orientation is gaining acceptance in radiation oncology and radiology and has distinct advantages over the recumbent position. An IRB approved study to investigate the positions and orientations of the male pelvic organs between the supine and upright positions was conducted. The study comprised of scanning 15 male volunteers (aged 55-75 years) on a 0.6 T Fonar MRI scanner in the supine and upright positions with a full bladder and in the upright position with an empty bladder. The Pelvic study revealed that in the upright position the 1. Position and shape of the prostate are not impacted significantly by bladder fill. 2. Distance between the sacrum and the anterior bladder wall is significantly smaller. 3. Anterior-Posterior length and the bladder width is significantly larger. 4. Seminal vesicles are pushed down by the bladder. 5. Top of the penile bulb is further away from the apex of the prostate. These observed differences could positively impact upright prostate treatments by 1. Reducing the risk of small bowel approximating the treatment volume. 2. Prostate treatments can be done with a reduced focus on bladder fill. 3. Radiation beams for treating intermediate risk prostrate can be made smaller or a larger portion of the seminal vesicles can be treated with the same beam size than typically used for supine treatments. 4. Reducing the average dose to the penile bulb.

Barriers and facilitators of implementing the practice programme for upright positions in the second stage of labour: A mixed-method study.

OBJECTIVE: To explore the possible barriers and facilitators to implementing the Upright Positions in the Second Stage of Labour (UPSSL) programme in Chinese healthcare settings. DESIGN: A mixed-method convergent design with the guidance of Consolidated Framework for Implementation Research (CFIR). METHODS: An online survey study and semi-structured interviews were conducted between March and May 2023. Healthcare professionals were recruited from four hospitals in Shijiazhuang, China. One hundred and thirty-one participants completed the survey study, and 23 of them were interviewed individually. Descriptive statistics evaluated the possible barriers and facilitators of implementing the UPSSL programme within the CFIR framework quantitatively. Guided by the CFIR framework, qualitative data were analysed using directed content analysis to summarize healthcare professionals' perspectives on barriers and facilitators of the UPSSL programme. RESULTS: Multiple intersectional barriers and facilitators were identified from the survey and semi-interviews. Healthcare professionals believed that the UPSSL programme has a scientific evidence base, systematic contents, and possible benefits for women. However, various barriers existed at individual, system, and organizational levels. Major barriers included healthcare professionals and women's safety concerns towards the use of upright positions during childbirth, the healthcare professionals' unfamiliarity with assisting an upright position birth, poor adaptability of the programme protocol, inadequate facilities and staffing, and a lack of readiness to change in the clinical setting. CONCLUSIONS: To facilitate the implementation of the UPSSL programme in China, tailored antenatal education on upright positions, especially addressing safety-related issues, should be provided to pregnant women, their families, or peers to enhance their understanding of and familiarity with such positions. Healthcare professionals should also be offered adequate training opportunities and necessary facilities. Furthermore, national-level policy changes might be required to address midwifery workforce shortages. Additionally, further research is warranted to select, adapt, and test effective implementation strategies for programme adoption. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: What problem did the study address? The adoption of upright positions during the second stage of labour could promote better maternal and neonatal outcomes and a positive childbirth experience. However, the adoption of upright positions during the second stage of labour is suboptimal in healthcare settings in China. Barriers and facilitators of implementing upright positions during childbirth are unclear. What were the main findings? A range of barriers and facilitators within the CFIR framework to promote upright positions during childbirth from healthcare professionals' perspectives were identified, and the major barriers included safety concerns towards and unfamiliarity with an upright position birth, inadequate facilities and staffing, and a lack of readiness to change in the clinical setting. Where and on whom will the research have an impact? This study will enable a better understanding of the barriers and facilitators to promoting upright positions in the second stage of labour in China. The smooth and effective implementation of the UPSSL programme could help to promote better maternal and neonatal outcomes and improve women's childbirth experiences. REPORTING METHOD: The reporting of this study followed the Consolidated Criteria for Reporting Qualitative Research (COREQ) and Good Reporting of A Mixed Methods Study (GRAMMS) guidelines. PATIENT OR PUBLIC CONTRIBUTION: In this study, healthcare professionals were involved in refining the topic guides and survey questions. Additionally, findings from the interviews were returned to them for comments and corrections.

[Posterior inferior cerebellar artery infarction with episodic postural diplopia as the initial symptom: A case report].

Accurate and timely diagnosis of posterior circulation ischemic stroke is a challenge for emergency neurology clinicians, even MRI scan which is believed to be sensitive to acute ischemic lesions may be negative. It is particularly important to obtain the typical or characteristic symptoms and signs of the patients through comprehensive physical examination. We report a case of posterior inferior cerebellar artery (PICA) territory infarction with "episodic postural diplopia" as the initial symptom, hoping that clinicians notice the vertical diplopia caused by the disfunction of otolith gravity conduction pathway, which is characterized by the degree of diplopia being affected by postural changes. A 44-year-old man was in hospital due to episodic postural diplopia for 4 months, dizziness and unstable walking for 5 days. In the past four months, the patient had endured episodic diplopia attack for 8 times when standing or walking, which could be relieved obviously while lying down and gradually disappeared within 5-10 minutes. He had not seen a doctor since the outbreak of the novel coronavirus. Five days before admission, diplopia worsened accompanying obvious vertigo, nausea and vomiting, left facial numbness, and hiccups. The diplopia could be relieved after taking the supine position, but not completely disappear as before. Physical examination showed a triad of ocular tilt response (OTR), namely static ocular rotation (SOT), skew deviation (SD) and head tilt (HT). And also subjective visual vertical (SVV) deviation was found. Those signs were considered for otolith gravity conduction system involvement. Combined with other clinical signs, such as Horner signs, crossed sensory disorders, ataxia, and MRI scan, it was easy to find the infarction was in the territory of the left PICA. The reasons for the patient's "episodic posi-tional diplopia" in the early stage of the disease were considered as follows: (1) the gravity was less affected in the supine position, the stimulation of the otolith gravity conduction pathway was reduced, so the degree of eye deviation was reduced in the supine position. (2) As an ischemic cerebrovascular disease, the patient experienced a process of transient ischemic attack (TIA) in the posterior circulation, the cerebral blood supply and the hypoperfusion of stenosis were increased after lying down, so the diplopia symptom disappeared. The upright-supine test was recommended for the patients with vertical diplopia. It was recommened to differentiate between otolith pathway involvement and diplopia caused by trochlear nerve palsy.

Effect of Trunk Solution® on hemodynamics in the supplementary motor area during walking.

[Purpose] Humans keep their trunks vertical while walking. This defining characteristic is known as upright bipedalism. Research on the neural control of locomotion indicates that not only subcortical structures, but also the cerebral cortex, especially the supplementary motor area (SMA), is involved in locomotion. A previous study suggested that SMA may contribute to truncal upright posture-control during walking. Trunk Solution® (TS) is a trunk orthosis designed to support the trunk in decreasing the low back load. We hypothesized that the trunk orthosis might reduce the burden of truncal control on the SMA. The objective of this study was, therefore, to determine the effect of trunk orthosis on the SMA during walking. [Participants and Methods] Thirteen healthy participants were enrolled in the study. We measured the hemodynamics of the SMA during walking with functional near-infrared spectroscopy (fNIRS). The participants performed two gait tasks on a treadmill: (A) independent gait (usual gait) and (B) supported gait while wearing the TS. [Results] During (A) independent gait, the hemodynamics of the SMA exhibited no significant changes. During (B) gait with truncal support, the SMA hemodynamics decreased significantly. [Conclusion] TS may reduce the burden of truncal control on the SMA during walking.

Pelvic inclination correction system for magnetic resonance imaging analysis of pelvic organ prolapse in upright position.

INTRODUCTION AND HYPOTHESIS: Pelvic organ prolapse quantification by means of upright magnetic resonance imaging (MRI) is a promising research field. This study determines the angle for the pelvic inclination correction system (PICS) for upright patient position, which is hypothesized to deviate from the supine PICS angle. The necessity of different PICS angles for various patient positions will also be discussed. METHODS: Magnetic resonance scans of 113 women, acquired in an upright patient position, were used to determine the upright PICS angle, defined as the angle between the sacrococcygeal-inferior pubic point (SCIPP) line and the horizontal line. The difference and correlation between the upright and supine PICS angles were calculated using the paired Student's t-test and the Pearson's correlation coefficient (r) respectively. The effect of the difference between the upright and supine PICS angle on the measured pelvic organ extent was calculated using goniometry. RESULTS: The mean (interquartile range) PICS angles were 29° (26-35°) for the upright and 33° (30-37°) for the supine patient position. They were significantly different (p<0.001) and very strongly correlated (r = 0.914, p<0.001). The 4° difference between the average upright and supine PICS angle results in an average underestimation of the measured cervix height of approximately 0.5 cm for patients scanned in upright position. CONCLUSIONS: The PICS angle for the upright patient position is 29°. The use of a dedicated PICS angle for different patient positions allows for more accurate pelvic organ extent analysis in patients with prolapse.

The influence of spinal position on imaging findings: an observational study of thoracolumbar spine upright MRI in elite gymnasts.

PURPOSE: To investigate whether upright magnetic resonance imaging (MRI) has a role in defining thoracolumbar spine pathology in elite gymnastics. METHODS: A prospective cross-sectional observational study of National Senior and Junior Artistic gymnasts in three MRI positions (standard supine, upright flexed and extended positions). Two specialist musculoskeletal radiologists independently analysed images with neutral as a baseline with the effects of flexion and extension reported in line with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. RESULTS: Forty (18 males) gymnasts aged 13-24 years with a mean (SD) of 32 (5.3) training hours per week consented with 75% showing MRI abnormalities. Degenerative disc disease (DDD) was evident in 55% participants with vertebral end plate (VEP) changes in 42.5%. Spondylolysis was present in 40% with an additional 17% showing chronic bilateral complete L5 pars defects. 23% participants demonstrated different MRI findings in upright flexion compared to neutral. CONCLUSION: Findings suggest a high levels of MRI abnormalities in elite gymnastics including altered disc morphology and posterior element abnormalities. High prevalence of T11/12 DDD and VEP changes reflects the thoracolumbar junction being a transition zone. Upright MRI and varying spine position offer promise for enhanced visualisation of posterior element abnormalities.

Relationship between hip joint proximity area and sagittal balance parameters: an upright computed tomography study.

PURPOSE: A close relationship between sagittal spinal alignment and hip osteoarthritis (OA) has been documented. This study aimed to examine the relationship between hip joint proximity area and sagittal balance parameters in healthy subjects. METHODS: This prospective study enrolled 47 healthy volunteers who underwent 320-detector row upright computed tomography. Acquired data were reconstructed in a virtual three-dimensional space. The proximity area was determined by < 1 mm of the Hausdorff distance between the acetabulum and the femoral head. Volunteers were divided into the anterior and posterior proximity groups depending on the position of the closest area. Sagittal balance parameters [sagittal vertical axis (SVA), T1 spinopelvic inclination (T1-SPi), T1-pelvic angle, pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis, thoracic kyphosis), offset distance between the centre of the acoustic meati (CAM) and C7 plumb line (CAM-C7-offset), and offset distance between the CAM and hip axis (HA) (CAM-HA-offset)] were compared between the two groups using independent sample t test. RESULTS: The anterior proximity group (n = 24) had higher SVA (p = 0.016) and T1-Spi (p = 0.015) than the posterior proximity group (n = 23). CAM-HA-offset was higher in the posterior than in the anterior proximity group (p < 0.000). There was no difference in other parameters (p > 0.05). CONCLUSION: The anterior proximity group had a positive anterior spinal balance; the posterior proximity group may have a more posterior gravity line than the hip joint centre. The anterior spinal balance may contribute to the anterior loading of the hip joint, with known relation with the initiation and onset of hip OA.

Utility of upright radiographs in traumatic thoracolumbar fracture management.

BACKGROUND: It is common practice to use a combination approach of computed tomography (CT) scan followed by upright radiographs when assessing traumatic thoracolumbar (TL) vertebral fractures. The purpose of this study was to determine the clinical utility of upright spine radiographs in the setting of traumatic TL fracture management. Our null hypothesis is that upright TL radiographs rarely change management of acute vertebral fractures. METHODS: A retrospective study was performed on patients with an initial plan of non-operative management for a TL fracture between January 2014 and June 2020 at a single Level 1 trauma center. Patients were followed from time of initial consult to either conversion to surgery (operative) or last available outpatient follow up imaging (non-operative). Lateral kyphotic angle of the fractured vertebra and anterior vertebral body height% loss on initial CT, first upright radiograph, and endpoint upright radiograph imaging were measured. Measurements were compared between and within operative and non-operative groups using t-tests and Mann-Whitney U tests when appropriate. P-values ≤ 0.05 were considered statistically significant. RESULTS: The study included 70 patients with an average age of 54 years and 37 (52.9%) were women. Six (8.6%) of 70 patients had a change from non-operative to operative management based on upright radiographs. The mean (standard deviation) change in degrees of kyphosis from CT scan to first X-ray was 4.6 (7.0) in the non-operative group and 11.5 (8.1) in the operative group (P = 0.03). Delta degrees of kyphosis from CT scan to endpoint X-ray was 6.4 (9.0) and 16.2 (6.2) in the non-operative and operative groups, respectively (P = 0.01). In the operative group, mean degrees of kyphosis increased from 1.6 (7.6) in initial CT to 13.1 (8.9) in first X-ray (P = 0.02). First X-ray mean anterior body height% loss was 37.5 (17.6) and 53.2 (16.1) in the non-operative and operative groups, respectively (P = 0.04). CONCLUSIONS: Upright radiographs are useful in guiding traumatic vertebral fracture management decisions. Larger studies are needed to determine the degree of change in kyphosis between CT and first standing radiograph that is suggestive of operative management. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: Not applicable.