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Background and aims: Osteopenia and osteoporosis are frequent in Crohn's disease. However, there are few data on related vertebral fractures. Therefore, we evaluated prospectively the prevalence of osteoporotic vertebral fractures [...]

Microgravity and inactivity due to prolonged bed rest have been shown to result in atrophy of spinal extensor muscles such as the multifidus, and either no atrophy or hypertrophy of flexor muscles such as the abdominal group and psoas muscle. These effects are long-lasting after bed rest and the potential effects of rehabilitation are unknown. This two-group intervention study aimed to investigate the effects of two rehabilitation programs on the recovery of lumbo-pelvic musculature following prolonged bed rest. 24 subjects underwent 60 days of head down tilt bed rest as part of the 2nd Berlin BedRest Study (BBR2-2). After bed rest, they underwent one of two exercise programs, trunk flexor and general strength (TFS) training or specific motor control (SMC) training. Magnetic resonance imaging of the lumbo-pelvic region was conducted at the start and end of bed rest and during the recovery period (14 and 90 days after re-ambulation). Cross-sectional areas (CSAs) of the multifidus, psoas, lumbar erector spinae and quadratus lumborum muscles were measured from L1 to L5. Morphological changes including disc volume, spinal length, lordosis angle and disc height were also measured. Both exercise programs restored the multifidus muscle to pre-bed-rest size, but further increases in psoas muscle size were seen in the TFS group up to 14 days after bed rest. There was no significant difference in the number of low back pain reports for the two rehabilitation groups (p=.59). The TFS program resulted in greater decreases in disc volume and anterior disc height. The SMC training program may be preferable to TFS training after bed rest as it restored the CSA of the multifidus muscle without generating potentially harmful compressive forces through the spine. [ABSTRACT FROM AUTHOR]

STUDY DESIGN.: Prospective longitudinal study. OBJECTIVE.: To evaluate the effect of bed-rest on the lumbar musculature and soft-tissues. SUMMARY OF BACKGROUND DATA.: Earlier work has suggested that the risk of low back injury is higher after overnight bed-rest or spaceflight. Changes in spinal morphology and atrophy in musculature important in stabilizing the spine could be responsible for this, but there are limited data on how the lumbar musculature and vertebral structures are affected during bed-rest. METHODS.: Nine male subjects underwent 60-days head-down tilt bed-rest as part of the second Berlin Bed-Rest Study. Disc volume, intervertebral spinal length, intervertebral lordosis angle, and disc height were measured on sagittal plane magnetic resonance images. Axial magnetic resonance images were used to measure cross-sectional areas (CSAs) of the multifidus (MF), erector spinae, quadratus lumborum, and psoas from L1 to L5. Subjects completed low back pain (LBP) questionnaires for the first 7-days after bed-rest. RESULTS.: Increases in disc volume, spinal length (greatest at lower lumbar spine), loss of the lower lumbar lordosis, and move to a more lordotic position at the upper lumbar spine (P < 0.0097) were seen. The CSAs of all muscles changed (P < 0.002), with the rate of atrophy greatest at L4 and L5 in MF (P < 0.002) and at L1 and L2 in the erector spinae (P = 0.0006). Atrophy of the quadratus lumborum was consistent throughout the muscle (P = 0.15), but CSA of psoas muscle increased (P < 0.0001). Subjects who reported LBP after bed-rest showed, before reambulation, greater increases in posterior disc height, and greater losses of MF CSA at L4 and L5 than subjects who did not report pain (all P < 0.085). CONCLUSION.: These results provide evidence that changes in the lumbar discs during bed-rest and selective atrophy of the MF muscle may be important factors in the occurrence of LBP after prolonged bed-rest. [ABSTRACT FROM AUTHOR]

In a multitude of applications like e.g. in automotive radar systems a localization of multiple passive targets in the observed area is necessary. This contribution presents a robust approach based on trilateration to detect point scatterers in a two-dimensional plane using the reflection and transmission information of only two antennas. The proposed algorithm can identify and remove ambiguities in target detection which unavoidably occur in certain target constellations in such a two-antenna configuration. [ABSTRACT FROM AUTHOR]

This contribution deals with the results of a transient measurement campaign incorporating ultra-wideband (UWB) pulses applied to a large GTEM cell. The main purpose is to analyse the distortion effects on such a feeding pulse when transformed into a field pulse inside the cells testing volume. We will investigate if the TEM field distribution is interfered by multimode propagation, that may lead to location-dependent pulse distortion and ringing. Finally, conclusions on the applicability of GTEM cells for standardized transient EMC measurements will be drawn. [ABSTRACT FROM AUTHOR]

This contribution deals with guided radar level measurements of liquid materials in large metal tubes, so-called stilling wells, bypass or still pipes. In the RF domain these tubes function as overmoded circular waveguides and mode-matched excitation structures like waveguide tapers are needed to avoid higher order waveguide modes. Especially for high-precision radar measurements the multimode propagation effects need to be minimized to achieve submillimeter accuracy. Therefore, a still pipe simulator is introduced with the purpose to fundamentally analyze the modal effects. Furthermore, a generalized design criterion is derived for the spurious mode suppression of compact circular waveguide transitions under the constraint of specified accuracy levels. According to the obtained results, a promising waveguide taper concept will finally be presented. [ABSTRACT FROM AUTHOR]

Starting from planar broadband log.-per. antenna design, offering the possibility of dual-polarized reception properties, in this article a generalized mathematical approach for rapidly estimating the resulting signal correlation coefficient in a stochastically modeled propagation environment solely based on measured or simulated radiation characteristics of one single antenna element is presented. The obtained results are marking an upper limit and are describing the worst-case scenario according to the signal correlation at the antenna feeding points in terms of line-of-sight (LOS) reception in main beam direction. The knowledge of the derived relationship may be helpful especially for antenna designers to combine antenna performance values with the significant communication system performance parameters, as e.g. in case of Multiple-Input Multiple-Output (MIMO) and diversity configurations [ABSTRACT FROM AUTHOR]

Several studies have tried to find countermeasures against musculoskeletal de-conditioning during bed-rest, but none of them yielded decisive results. We hypothesised that resistive vibration exercise (RVE) might be a suitable training modality. We have therefore carried out a bed-rest study to evaluate its feasibility and efficacy during 56 days of bed-rest. Twenty healthy male volunteers aged 24 to 43 years were recruited and, after medical check-ups, randomised to a non-exercising control (Ctrl) group or a group that performed RVE 11 times per week. Strict bed-rest was controlled by video surveillance. The diet was controlled. RVE was performed in supine position, with a static force component of about twice the body weight and a smaller dynamic force component. RVE comprised four different units (squats, heel raises, toe raises, kicks), each of which lasted 60-100 seconds. Pre and post exercise levels of lactate were measured once weekly. Body weight was measured daily on a bed scale. Pain questionnaires were obtained in regular intervals during and after the bed-rest. Vibration frequency was set to 19 Hz at the beginning and progressed to 25.9 Hz (SD 1.9) at the end of the study, suggesting that the dynamic force component increased by 90%. The maximum sustainable exercise time for squat exercise increased from 86 s (SD 21) on day 11 of the BR to 176s (SD 73) on day 53 (p = 0.006). On the same days, post-exercise lactate levels increased from 6.9 mmol/l (SD2.3) to 9.2 mmol/l (SD 3.5, p = 0.01). On average, body weight was unchanged in both groups during bed-rest, but single individuals in both groups depicted significant weight changes ranging from -10% to +10% (p <0.001). Lower limb pain was more frequent during bed-rest in the RVE subjects than in Ctrl (p = 0.035). During early recovery, subjects of both groups suffered from muscle pain to a comparable extent, but foot pain was more common in Ctrl than in RVE (p = 0.013 for plantar pain, p = 0.074 for dorsal foot pain). Our results indicate that RVE is feasible twice daily during bed-rest in young healthy males, provided that one afternoon and one entire day per week are free. Exercise progression, mainly by progression of vibration frequency, yielded increases in maximum sustainable exercise time and blood lactate. In conclusion, RVE as performed in this study, appears to be safe. [ABSTRACT FROM AUTHOR]

In order to satisfy the stringent demand for an accurate prediction of MIMO channel capacity and diversity performance in wireless communications, more effective and suitable models that account for real antenna radiation behavior have to be taken into account. One of the main challenges is the accurate modeling of antenna correlation that is directly related to the amount of channel capacity or diversity gain which might be achieved in multi element antenna configurations. Therefore spherical wave theory in electromagnetics is a well known technique to express antenna far fields by means of a compact field expansion with a reduced number of unknowns that was recently applied to derive an analytical approach in the computation of antenna pattern correlation. In this paper we present a novel and efficient computational technique to determine antenna pattern correlation based on the evaluation of the surface current distribution by means of a spherical mode expansion. [ABSTRACT FROM AUTHOR]

Deployment in the design of mobile radio terminals focuses on the implementation of multiradio transmission systems, using a multiplicity of different radio standards combined with high-speed data communication over multiple-input multiple-output (MIMO) and multimode diversity techniques. Hence, planar log.-per. four-arm antennas are predistined to meet the requirements of future mobile multiradio RF-frontends and will be introduced and analysed in terms of an efficient spherical mode analysis by means of surface current distribution in order to derive an analytic access to MIMO- and polarisation-diversity performance computation. A remarkable parameter reduction and a faster numerical analysis with respect to conventional techniques may be achieved. The sources in the near-field antenna region are based on the numerical computation of surface currents involving the finite element method (FEM). Relations between the variations of the geometrical antenna parameters and the excitation of discrete spherical modes are presented and will be analysed in detail. [ABSTRACT FROM AUTHOR]

Establishing the long-term repeatability of quantitative measures of lumbar intervertebral disc and spinal morphology is important for planning interventional studies. We aimed to examine this issue and to determine to what extent a smaller number of measurements per disc or vertebral level could be used to save operator time without compromising measurement precision. Twenty-one healthy male subjects were scanned at baseline and 1.5 years later. On sagittal MR-scans intervertebral disc cross-sectional area, anterior disc height, posterior disc height, intervertebral angle and intervertebral length were measured. The repeatability of the average value from all sagittal images or from 1, 3, 5 or 7 images centred at the spinous process was evaluated. Bland–Altman analysis showed all measurements to be repeatable between testing days. Intervertebral length was the most precise measurement (coefficients of variation [CVs] between 1.2% and 1.5%), followed by disc cross-sectional area (CVs between 2.9% and 3.6%). Variance component analysis showed that using 7 images, but not 1, 3 or 5 images, resulted in a similar level of measurement error as when measurements from all images were included. [ABSTRACT FROM AUTHOR]

Evidence on the effects of Vitamin D, omega-3s, and exercise on areal bone mineral density (aBMD) in healthy older adults is limited. We examined whether vitamin D3, omega-3s, or a simple home-based exercise program (SHEP), alone or in combination, over 3 years, improve lumbar spine (LS), femoral neck (FN), or total hip (TH) aBMD assessed by DXA. Areal BMD was a secondary outcome in DO-HEALTH, a 3-year, multicenter, double-blind, randomized 2 × 2 × 2 factorial design trial in generally healthy older adults age ≥ 70 years. The study interventions were vitamin D3 (2000IU/d), omega-3s (1 g/d), and SHEP (3 × 30 min/wk), applied alone or in combination in eight treatment arms. Mixed effects models were used, adjusting for age, sex, BMI, prior fall, study site, and baseline level of the outcome. Main effects were assessed in the absence of an interaction between the interventions. Subgroup analyses by age, sex, physical activity level, dietary calcium intake, serum 25(OH)D levels, and fracture history were conducted. DXA scans were available for 1493 participants (mean age 75 years; 80.4% were physically active, 44% had 25(OH)D levels <20 ng/mL). At the LS and FN sites, none of the treatments showed a benefit. At the TH, vitamin D versus no vitamin D treatment showed a significant benefit across 3 years (difference in adjusted means [AM]: 0.0035 [95% CI, 0.0011, 0.0059] g/cm). Furthermore, there was a benefit for vitamin D versus no vitamin D treatment on LS aBMD in the male subgroup (interaction P = .003; ∆AM: 0.0070 [95% CI, 0.0007, 0.0132] g/cm). Omega-3s and SHEP had no benefit on aBMD in healthy, active, and largely vitamin D replete older adults. Our study suggests a small benefit of 2000 IU vitamin D daily on TH aBMD overall and LS aBMD among men; however, effect sizes were very modest and the clinical impact of these findings is unclear., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society for Bone and Mineral Research.)

Objective: Although aging has a strong impact on visual acuity (VA) and falls, their interaction is understudied in generally healthy older adults. This study aimed to examine if and to what extent baseline VA is associated with an increased risk of all and injurious falls over 3 years in generally healthy community-dwelling older adults., Design: Observational analysis of DO-HEALTH, a double-blind, randomized controlled trial., Setting and Participants: Multicenter trial with 7 European centers: Zurich, Basel, Geneva (Switzerland), Berlin (Germany), Innsbruck (Austria), Toulouse (France), and Coimbra (Portugal), including 2157 community-dwelling adults aged 70 years and older without any major health events in the 5 years prior to enrollment, sufficient mobility, and good cognitive status., Methods: The numbers of all and injurious falls were recorded prospectively by diary and in-person assessment every 3 months. Decreased VA at baseline was defined as better-eye VA lower than 1.0. We applied negative binomial regression models for all and injurious falls, adjusted for age, sex, prior falls, treatment allocation, study site, baseline body mass index, and use of walking aids., Results: Among the 2131 participants included in this analysis (mean age: 74.9 years, 61.7% were women, 82.6% at least moderately physically active), 1464 (68.7%) had decreased VA. Overall, 3290 falls including 2116 injurious falls were recorded over 3 years. Decreased VA at baseline was associated with a 22% increased incidence rate of all falls [adjusted incidence rate ratio (aIRR) = 1.22, 95% CI 1.07, 1.38, P = .003] and 20% increased incidence rate of injurious falls (aIRR = 1.20, 95% CI 1.05, 1.37, P = .007)., Conclusions and Implications: Our findings suggest that decreased VA is an independent predictor of an about 20% increased risk of all and injurious falls, highlighting the importance of regular eye examinations and VA measurements for fall prevention, even in generally healthy and active older adults., Competing Interests: Disclosure As part of the DO-HEALTH independent and investigator-initiated clinical trial, H.A.B.-F. reports, as the principal investigator of the DO-HEALTH trial, grants from the European Commission, the University of Zurich, Nestec, Pfizer Consumer Healthcare, and Streuli Pharma, and nonfinancial support from DSM Nutritional Products and Roche Diagnostics. Further, H.A.B.-F. reports speaker fees from Wild, Pfizer, Vifor, Mylan, Roche Diagnostics, and independent and investigator-initiated grants from Pfizer and from Vifor, outside of the submitted work. E.J.O. was also funded by DO-HEALTH. J.A.K. is a director of Osteoporosis Research Ltd. that maintains FRAX. M.D.B. reports speaking engagements for Roche Pharma (Schweiz) AG and consulting roles for Hoffmann-La Roche Ltd., Roche Pharma (Schweiz) AG, and ZEISS meditec (Deutschland). He is a lead user for Oertli (Schweiz) and holds patents and equity in Ophthorobotics AG. His contracted research includes work with Roche Pharma (Schweiz) AG, Novertis Pharma Schweiz AG, Chengdu Kanghong, and Bayer (Schweiz) AG. He has also received grant support from the W.H. Spross Stiftung zur Förderung der Augenheilkunde and the Stiftung für wissenschaftliche Forschung am Stadtspital Zürich. All other authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: While grip strength (GS) is commonly assessed using a Dynamometer, the Martin Vigorimeter was proposed as an alternative method especially in older adults. However, its reference values for Swiss older adults are missing. We therefore aimed to derive sex- and age-specific GS cut-points for the dominant and non-dominant hand (DH; NDH) using the Martin Vigorimeter. Additionally, we aimed to identify clinically relevant weakness and assess convergent validity with key markers of physical function and sarcopenia in generally healthy Swiss older adults., Methods: This cross-sectional analysis includes baseline data from Swiss participants enrolled in DO-HEALTH, a 3-year randomized controlled trial in community-dwelling adults age 70 + . For both DH and NDH, 4 different definitions of weakness to derive GS cut-points by sex and age category (≤ 75 vs. > 75 years) were used: i) GS below the median of the 1 st quintile, ii) GS below the upper limit of the 1 st quintile, iii) GS below 2-standard deviation (SD) of the sex- and age-specific mean in DO-HEALTH Swiss healthy agers (i.e. individuals without major chronic diseases, disabilities, cognitive impairment or mental health issues) and iv) GS below 2.5-SD of the sex- and age-specific mean in DO-HEALTH Swiss healthy agers. To assess the proposed cut-points' convergent validity, we assessed their association with gait speed, time to complete the 5 Times Sit-To-Stand (5TSTS) test, and present sarcopenia., Results: In total, 976 participants had available GS at the DH (mean age 75.2, 62% women). According to the 4 weakness definitions, GS cut-points at the DH ranged from 29-42 and 25-39 kPa in younger and older women respectively, and from 51-69 and 31-50 kPa in younger and older men respectively. Overall, weakness prevalence ranged from 2.0% to 19.3%. Definitions of weakness using the median and the upper limit of the 1 st GS quintile were most consistently associated with markers of physical performance. Weak participants were more likely to have lower gait speed, longer time to complete the 5TSTS, and sarcopenia, compared to participants without weakness., Conclusions: In generally healthy Swiss older adults, weakness defined by the median or the upper limit of the 1 st GS quintile may serve as reference to identify clinically relevant weakness. Additional research is needed in less healthy populations in order to derive representative population-based cut-points., Trial Registration: ClinicalTrials.gov Identifier: NCT01745263., (© 2023. European Group for Research into Elderly and Physical Activity (EGRIPA).)

Background: This primary analysis evaluated the "PREVenting the impairment of primary Osteoarthritis by high-impact long-term Physical exercise regimen-Psychological Adherence Program" (PrevOP-PAP), designed to support patients with osteoarthritis of the knee (OAK) to engage in regular moderate-to-vigorous physical activity (MVPA) to reduce OAK symptoms (WOMAC scores). Theory-based on the health action process approach (HAPA), the intervention targeted volitional precursors of MVPA change: action and coping planning, maintenance and recovery self-efficacy, action control, and social network formation. We hypothesized that compared to an active control condition, increases in MVPA at the end of the 12-month intervention would translate into lower WOMAC scores at 24 months in the intervention condition., Methods: Participants with radiographically verified moderate OAK (N = 241; 62.66% female; M(SD) = 65.60(7.61) years) were randomly assigned to the intervention (51%) or the active control condition. WOMAC scores (24 months) were the primary -, accelerometer-assessed MVPA (12 months) the key secondary outcomes. The PrevOP-PAP was a 12-month intervention with computer-assisted face-to-face and phone-based sessions designed to increase HAPA-proposed volitional precursors of MVPA change (up to 24 months; secondary outcomes). Intent-to-treat analyses included multiple regression and manifest path models., Results: MVPA (12 months) did not mediate effects of the PrevOP-PAP on WOMAC scores (24 months). Compared to the active control condition, WOMAC scores (24 months) were lower in the intervention condition, but this effect did not remain stable in sensitivity analyses (b(SE) = -8.41(4.66), 95%-CI [-17.53; 0.71]). However, exploratory analyses revealed significantly stronger reductions in WOMAC-pain (24 months) in the intervention condition (b(SE) = -2.99(1.18), 95%-CI [-5.36; -0.63]). Groups did not differ in MVPA at 12 months (b(SE) = -3.78(3.42), 95%-CI [-10.80; 2.58]). Of the proposed precursors of MVPA change, action planning was higher in the intervention than in the control condition (24 months; b(SE) = 0.64(0.26), 95%-CI [0.14; 1.15])., Conclusions: Compared to an active control condition, the PrevOP-PAP did not produce reliable effects on WOMAC scores and none on preceding MVPA. Of the HAPA-proposed volitional precursors, only action planning was sustainably increased. Future interventions should use m-health applications to digitally support long-term changes in proposed volitional precursors of MVPA change., Trial Registration: German Clinical Trials Register; https://drks.de/search/de/trial/DRKS00009677 ; also available at http://apps.who.int/trialsearch/ ; registration number: DRKS00009677; date of registration: 26/01/2016., (© 2023. The Author(s).)

Objective: To examine the association between the baseline number of chronic diseases and multimorbidity with regard to the incidence of all and injurious falls over 3 years among European community-dwelling older adults., Design: Observational analysis of DO-HEALTH, a double-blind, randomized controlled trial., Setting and Participants: Multicenter trial with 7 European centers: Zurich, Basel, Geneva (Switzerland), Berlin (Germany), Innsbruck (Austria), Toulouse (France), and Coimbra (Portugal), including 2157 community-dwelling adults aged 70 years and older without any major health events in the 5 years prior to enrollment, sufficient mobility, and good cognitive status., Methods: The main outcomes were the number of all falls and injurious falls experienced over 3 years. The number of chronic diseases and multimorbidity, defined as the presence of 3 or more chronic diseases at baseline, were assessed with the Self-Administered Comorbidity Questionnaire by Sangha et al., Results: Among the 2155 participants included in the analyses (mean age: 74.9 years, 62% were women, 52% were physically active more than 3 times a week), 569 (26.4%) had multimorbidity at baseline. Overall, each 1-unit increase in the baseline number of chronic diseases was linearly associated with a 7% increased incidence rate of all falls [adjusted incidence rate ratio (aIRR) 1.07, 95% CI 1.03-1.12, P < .001] and a 6% increased incidence rate of injurious falls (aIRR 1.06, 95% CI 1.02-1.11, P = .003). Baseline multimorbidity was associated with a 21% increased incidence rate of all falls (aIRR 1.21, 95% CI 1.07-1.37, P = .002) and a 17% increased incidence rate of injurious falls (aIRR 1.17, 95% CI 1.03-1.32, P = .02)., Conclusions and Implications: Baseline number of prevalent chronic diseases and multimorbidity in generally healthy and active community-dwelling older adults were associated with increased incidence rates of all and injurious falls over 3 years. These findings support that multimorbidity may need consideration as a risk factor for falls, even in generally healthy and active older adults., (Copyright © 2022 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Iron metabolism imbalance could contribute to physical deconditioning experienced by astronauts due to its essential role in energy metabolism, cellular respiration, and oxygen transport., Objectives: In this clinical exploratory study, we wanted to determine whether artificial gravity (AG) training modulated iron metabolism, RBC indices, and body lean mass in healthy male and female participants exposed to head-down tilt (HDT) bed rest, the reference ground-based model of microgravity., Methods: We recruited 8 healthy female and 16 healthy male participants who were all exposed to HDT bed rest for 60 d. In addition, they were assigned to 3 experimental groups (n = 8/each): controls, continuous AG training in a short-arm centrifuge (1 × 30 min/d), and intermittent AG training (6 × 5 min/d)., Results: The iron metabolism responses to simulated microgravity of the AG training groups did not differ significantly from the responses of controls. Independently from AG, we found that both serum iron concentrations (+31.3%, P = 0.027) and transferrin saturation levels (+28.4%, P = 0.009) increased in males after 6 d of HDT bed rest, as well as serum hepcidin concentrations (+36.9%, P = 0.005). The increase of transferrin saturation levels persisted after 57 d of HDT bed rest (+13.5%, P = 0.026), suggesting that long-term exposure to microgravity sustainably increases serum iron availability in males, and consequently the risk of iron excess or misdistribution. In females, 6 and 57 d of HDT bed rest did not significantly change serum iron, transferrin saturation, or hepcidin levels., Conclusions: The data from this exploratory study suggest that 1) AG training does not influence the iron metabolism responses to microgravity; and 2) iron metabolism parameters, especially iron availability for cells, are significantly increased in males, but not in females, exposed to long-term simulated microgravity. Because of the small sample size of females, we nevertheless must be cautious before concluding that iron metabolism could differently respond to microgravity in females. This trial was registered at https://www.drks.de as DRKS00015677., (Copyright © 2022 American Society for Nutrition.)

Objective: In rheumatoid arthritis (RA), chronic inflammation can enhance the development of sarcopenia with a depletion of muscle mass, strength and performance. Currently, a consensus definition for sarcopenia and solid results for the prevalence of sarcopenia in patients with RA are lacking., Methods: In this cross-sectional study, 289 patients ≥18 years with RA were recruited. Dual X-ray absorptiometry was performed to measure appendicular lean mass. Assessment of muscle function included grip strength, gait speed and chair rise time. Prevalence of sarcopenia was defined using the updated European Working Group on Sarcopenia in Older People (EWGSOP2) and the Foundation for the National Institutes of Health (FNIH) definition. In addition, the RA study population was compared with existing data of healthy controls (n=280)., Results: 4.5% of patients (59.4±11.3 years) and 0.4% of controls (62.9±11.9 years) were affected by sarcopenia according to the EWGSOP2 definition. Body weight (OR 0.92, 95% CI 0.86 to 0.97), body mass index (BMI) (OR 0.70, 95% CI 0.57 to 0.87), C reactive protein (CRP) (OR 1.05, 95% CI 1.01 to 1.10), disease duration (OR 1.08, 95% CI 1.02 to 1.36), current medication with glucocorticoids (OR 5.25, 95% CI 2.14 to 24.18), cumulative dose of prednisone equivalent (OR 1.04, 95% CI 1.02 to 1.05) and Health Assessment Questionnaire (HAQ) (OR 2.50, 95% CI 1.27 to 4.86) were associated with sarcopenia in patients with RA. In contrast, the prevalence was 2.8% in patients compared with 0.7% in controls when applying the FNIH definition, and body height (OR 0.75, 95% CI 0.64 to 0.88), BMI (OR 1.20, 95% CI 1.02 to 1.41), CRP (OR 1.06, 95% CI 1.01 to 1.11) and HAQ (OR 2.77, 95% CI 1.17 to 6.59) were associated with sarcopenia., Conclusion: Sarcopenia is significantly more common in patients with RA compared with controls using the EWGSOP2 criteria. The FNIH definition revealed sarcopenia in individuals with high BMI and fat mass, regardless of the presence of RA., Trial Registration Number: It was registered at the German Clinical Trials Registry (DRKS) as well as WHO Clinical Trials Registry (ICTRP) (DRKS00011873, registered on 16 March 2017)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Astronauts have a higher risk of cervical intervertebral disc herniation. Several mechanisms have been attributed as causative factors for this increased risk. However, most of the previous studies have examined potential causal factors for lumbar intervertebral disc herniation only. Hence, we aim to conduct a study to identify the various changes in the cervical spine that lead to an increased risk of cervical disc herniation after spaceflight., Methods: A cohort study with astronauts will be conducted. The data collection will involve four main components: a) Magnetic resonance imaging (MRI); b) cervical 3D kinematics; c) an Integrated Protocol consisting of maximal and submaximal voluntary contractions of the neck muscles, endurance testing of the neck muscles, neck muscle fatigue testing and questionnaires; and d) dual energy X-ray absorptiometry (DXA) examination. Measurements will be conducted at several time points before and after astronauts visit the International Space Station. The main outcomes of interest are adaptations in the cervical discs, muscles and bones., Discussion: Astronauts are at higher risk of cervical disc herniation, but contributing factors remain unclear. The results of this study will inform future preventive measures for astronauts and will also contribute to the understanding of intervertebral disc herniation risk in the cervical spine for people on Earth. In addition, we anticipate deeper insight into the aetiology of neck pain with this research project., Trial Registration: German Clinical Trials Register, DRKS00026777. Registered on 08 October 2021., (© 2022. The Author(s).)

Background: Postural control is associated with fall risk. Patients with rheumatoid arthritis (RA) have a higher risk to fall than healthy subjects. The objective of this study was to identify associations between variables of postural control with prospective falls in patients with RA., Methods: For the baseline, the balance performance of 289 men and women with RA, ages 24-85 years, was evaluated by SPPB, FICSIT-4 and Romberg tests. Postural sway for Romberg, semitandem, tandem and one-leg stands were measured with the Leonardo Mechanograph®. Self-reported disability was assessed using the Health Assessment Questionnaire (HAQ) and the Activity-specific Balance Confidence Scale (ABC-scale). Falls were reported in quarterly reports over a year. Univariate and multiple logistic regression analysis were used to explore any associations with falling. Receiver-operating characteristics were determined, and the area under the curve is reported., Results: A total of 238 subjects completed the 1-year follow-up, 48 (20.2%) experienced at least one fall during the observational period. Age (OR = 1.04, CI 1.01-1.07), HAQ (OR = 1.62, 1.1-2.38), FICSIT-4 scoring 0-4 (OR = 2.38, 1.13-5.0), and one-leg standing (OR = 2.14, 1.06-4.31) showed significant associations with falls. With regard to the SPPB and ABC-scale, no statistically significant associations with falls were found. The quartiles containing the worst results of medio-lateral sway of Romberg (OR = 2.63, CI 1.03-6.69), total sway of semitandem (OR = 3.07, CI 1.10-8.57) and tandem (OR = 2.86, CI 1.06-7.69), and area of sway of semitandem (OR = 2.80, CI 1.11-7.08) stands were associated with falls., Conclusions: The assessment of a one-leg stand seems to be a good screening tool to discriminate between high and low risk of falls in RA patients in clinical practice. A low FICSIT-4 score and several sway parameters are important predictors of falls., Trial Registration: The study has been registered at the German Clinical Trials Register and the WHO International Clinical Trials Registry Platform (ICTRP) since 16 March 2017 ( DRKS00011873 )., (© 2022. The Author(s).)