Explore the vast range of titles available.

Accurate obesity classification is important so that appropriate intervention can be instituted to modify metabolic risk factors. Commonly utilized body mass index (BMI) and percentage body fat (PBF) are influenced by lean mass whereas fat mass index (FMI) measures only body fat. This study compares the prevalence of obesity and metabolic risk factors with FMI, BMI and PBF using DXA (dual-energy x-ray absorptiometry). 489 women randomly recruited from the electoral roll were stratified into 4 age groups; 40-49, 50-59, 60-69 and 70-79 years from 2000 to 2001. Clinical data and DXA body composition were obtained. Statistical analyses were performed using Medcalc v15 (Ostend, Belgium) with significance level at p = 0.05 (two-tailed). There was higher prevalence of obesity using PBF compared to BMI and FMI (p<0.001). This difference was greater from age 50-59 (p<0.05) which may be explained by age-related lean mass loss. PBF over-classified obesity in over 35% of normal and 95% of overweight categories compared to FMI and BMI. BMI has a sensitivity of 78.9% and specificity of 98.3% for obesity using FMI as the standard. BMI under-classified obesity in the overweight category by 14.9% compared to FMI. There was no difference in diabetes, dyslipidemia, hypertension and metabolic syndrome prevalence within the BMI-obesity and FMI-obesity categories (p>0.05). PBF classified more obesity than BMI and FMI because of its low pre-determined threshold. The greater difference with PBF compared to BMI and FMI from the 50-59 decade onwards can be attributed to age-related lean mass loss. BMI had the lowest sensitivity for obesity diagnosis. BMI under-classified obesity in the overweight category compared to FMI due to its inability to differentiate lean mass. However, there was no significant difference in the prevalence of metabolic risk factors between BMI and FMI-obesity categories indicating that fat location may influence metabolic dysregulation.

Osteoporotic fractures are associated with substantial morbidity and mortality. Although exercise has long been recommended for the prevention and management of osteoporosis, existing guidelines are often non-specific and do not account for individual differences in bone health, fracture risk and functional capacity. The aim of the current position statement is to provide health practitioners with specific, evidence-based guidelines for safe and effective exercise prescription for the prevention or management of osteoporosis, accommodating a range of potential comorbidities. Position statement. Interpretation and application of research reports describing the effects of exercise interventions for the prevention and management of low bone mass, osteoporosis and osteoporotic fracture. Evidence from animal and human trials indicates that bone responds positively to impact activities and high intensity progressive resistance training. Furthermore, the optimisation of muscle strength, balance and mobility minimises the risk of falls (and thereby fracture), which is particularly relevant for individuals with limited functional capacity and/or a very high risk of osteoporotic fracture. It is important that all exercise programs be accompanied by sufficient calcium and vitamin D, and address issues of comorbidity and safety. For example, loaded spine flexion is not recommended, and impact activities may require modification in the presence of osteoarthritis or frailty. Specific guidelines for safe and effective exercise for bone health are presented. Individual exercise prescription must take into account existing bone health status, co-morbidities, and functional or clinical risk factors for falls and fracture.

Background Weight loss achieved via energy restriction leads to significant losses in muscle and bone mass, potentially increasing risk for sarcopenia and osteoporosis. High‐intensity resistance and impact training (HiRIT) might attenuate weight loss–induced musculoskeletal declines. Our objective was to compare changes in physical function and body composition in older adults with obesity undertaking dietary weight loss combined with HiRIT or aerobic training (AT). Methods Sixty older adults (aged ≥ 60 years) with obesity (dual‐energy x‐ray absorptiometry determined body fat percentage ≥ 30% in men and ≥ 40% in women) and a mobility limitation (Short Physical Performance Battery [SPPB] score ≤ 11) were randomly assigned to either 12 weeks of supervised, centre‐based HiRIT or self‐directed, home‐based AT while consuming a hypocaloric diet (750–1000 kcal/day reduction in energy intake). Changes in physical function (primary outcome: gait speed) and body composition were compared between groups. Results A total of 49/60 randomised participants (mean age: 69.6 ± 6 years; 58% women; mean BMI: 32.9 ± 4.1 kg/m2) completed the trial. Gait speed increased following HiRIT compared with AT (mean difference: 0.07 m/s [95% CI: 0.01, 0.13]). Chair stand times decreased in both groups (HiRIT: −1.3 s [95% CI: −2.1, −0.4] vs. AT: −0.8 s [95% CI: −1.6, −0.04]) and HiRIT, but not AT, increased handgrip strength (HiRIT: 2.2 kg [95% CI: 0.6, 3.9] vs. AT: 0.7 kg [95% CI: −0.9, 2.3]) and SPPB scores (HiRIT: 0.9 [95% CI: 0.4, 1.3] vs. AT: 0.4 [95% CI: −0.04, 0.8]). Similar decreases in total body mass (HiRIT: −5.1 kg [95% CI: −6.7, −3.4] vs. AT: −4.9 kg [95% CI: −6.5, −3.3]), fat mass (HiRIT: −3.6 kg [95% CI: −5.0, −2.2] vs. AT: −3.3 kg [95% CI: −4.7, −2.0]), visceral fat (HiRIT: −32.1 cm2 [95% CI: −47.4, −16.8] vs. AT: −31.4 cm2 [95% CI: −46.1, −16.8]) and appendicular lean mass (HiRIT: −0.8 kg [95% CI: −1.4, −0.2] vs. AT: −1.2 kg [95% CI: −1.8, −0.6]) were observed. HiRIT was well tolerated with only seven minor adverse events compared with five reported in those who completed AT. Conclusion HiRIT appears to be safe and more effective than AT for improving gait speed in older adults with obesity undertaking dietary weight loss. Additional trials with larger sample sizes and longer durations are warranted to explore whether HiRIT can attenuate weight loss–related muscle and bone mass declines. Trial Registration: Australian New Zealand Clinical Trials: ACTRN12618001146280.

IntroductionAnimal studies suggest that elevated sympathetic nervous system (SNS) activity can accelerate bone loss. However, this area has not been well researched in humans. High-intensity Resistance and Impact Training (HiRIT) is recognised as an effective treatment for osteoporosis and osteopenia. Alternate forms of exercise such as mind-body exercise may be used to modulate sympathetic activity, which could have an additive benefit for skeletal adaptation when used in conjunction with HiRIT. The aim of this study is to investigate whether the combination of mind-body exercise (Tai Chi) and HiRIT can be used to concurrently modulate SNS activity and improve skeletal health.Methods and analysisThe CHILL BONES trial is a semi-randomised controlled trial where consenting adults over 60 years, who have low bone mass (total hip, femoral neck and/or lumbar spine T-score <−1.0) will be randomly allocated to participate in 8 months of twice-weekly Tai Chi, HiRIT or combined (Tai Chi+HiRIT) exercise. If participants are unwilling or unable to undertake exercise, they may opt into a non-exercising control group. The primary outcome will be total hip areal bone mineral density (BMD) measured using dual-energy X-ray absorptiometry. Secondary outcomes include femoral neck BMD, lumbar spine BMD, resting and reflexive skin sympathetic nerve activity and heart rate variability. Outcomes will be measured at baseline and post-intervention (8 months). Both intention-to-treat and per-protocol analyses will be undertaken.Ethics and disseminationEthical approval was granted by the Griffith University Human Research Ethics Committee (GUHREC; GU Ref No: 2023/448). Trial findings will be disseminated to participants via a plain-language summary upon completion. Results will be formally reported through peer-reviewed journals and conference presentations.Trial registration numberACTRN12623001209684; Australian New Zealand Clinical Trials Registry.

A considerable volume of evidence has accumulated to suggest that whole-body vibration (WBV) may have a therapeutic role to play in the prevention of osteoporotic fracture, particularly for individuals who are unable to tolerate vigorous exercise interventions. There is moderate to strong evidence that WBV will prevent falls (likely due to enhanced neuromuscular function), but also some indication that the effects of WBV do not outstrip those of targeted exercise. Animal data indicates that WBV will also improve bone mass, including preventing loss due to hormone withdrawal, disuse and glucocorticoid exposure. Human trials, however, have produced equivocal outcomes for bone. Positive trends are apparent at the hip and spine, but shortcomings in study designs have limited statistical power. The mechanism of the vibration effect on bone tissue is likely to be mechanical coupling between an oscillating cell nucleus and the cytoskeleton. More robust dose-response human data are required before therapeutic guidelines can be developed.

Musculoskeletal models typically use generic 2D models for the tibiofemoral (TFJ) and patellofemoral (PFJ) joints, with a hinge talocrural joint (TCJ), which are scaled to each subject׳s bone dimensions. Alternatively joints’ measured kinematics in cadavers are well-predicted using 3D cadaver-specific models. These employ mechanisms constrained by the articulations of geometric objects fitted to the joint׳s surfaces. In this study, we developed TFJ, PFJ and TCJ mechanism-based models off MRIs for fourteen participants and compared the estimated kinematics with those from published studies modified to be consistent with mechanisms models and subject-specific anatomical landmarks. The models’ parameters were estimated by fitting spheres to segmented articular cartilage surfaces, while ligament attachment points were selected from their bony attachment regions. Each participant׳s kinematics were estimated by ensuring no length changes in ligaments and constant distances between spheres’ centres. Two parameters’ optimizations were performed; both avoid singularities and one best matches the kinematic patterns off published studies. Sensitivity analysis determined which parameters the models were sensitive to. With both optimization methods, kinematics did not present singularities but correlation values were higher, exceeding 0.6, when matching the published studies. However, ranges of motion (ROM) were different between estimated and published studies. Across participants, models presented large parameter variation. Small variations were found between estimated- and optimized-parameters, and in the estimated-rotations and translations’ means and ROM. Model results were sensitive to changes in distal tibia, talus and patella spheres’ centres. These models can be implemented in subject-specific rigid-body musculoskeletal models to estimate joint moments and loads.

Background Supervised gym-based high-intensity resistance and impact training (HiRIT) can enhance physical function and muscle strength, but older adults may face challenges affecting adherence to HiRIT, such limited access to facilities and lack of transportation, necessitating a shift towards unsupervised home-based exercise. The aim of this study was to explore experiences and perspectives of older adults with obesity who were required to transition from supervised gym-based HiRIT to unsupervised home-based resistance training (RT) and aerobic training (AT) during COVID-19 lockdowns. Secondary aims were to compare changes in body composition and physical function after 12 weeks between participants required to transition to home-based exercise (“HOME”) and those who were able to continue gym-based exercise (“GYM”). Methods Thirty older adults (60–89 years) with obesity were enrolled from the gym-based HiRIT intervention arm of a 12-week exercise and dietary weight loss trial. Thirteen (43%) participants were transitioned to HOME due to COVID-19 lockdowns. HOME participants were prescribed bodyweight RT and AT exercises, while maintaining the weight loss intervention. Eight HOME participants completed semi-structured interviews post-intervention. Quantitative outcomes including exercise adherence, body composition and physical function were compared to GYM participants. Results Participants’ experiences and perspectives regarding the HOME program encompassed various elements including accessibility, accountability, maintaining physical activity levels, motivation, support from health care professionals, openness to telehealth videoconferencing for support, engagement, lack of equipment, supervision and a structured routine. Both groups had significant reductions in body mass (mean ± SD; GYM: -4.4 ± 0.4 kg, HOME: -6.2 ± 1.2 kg), but HOME demonstrated greater losses in fat mass (mean difference: -3.1 kg, 95% CI: -6.0, -0.3) compared with GYM represented by a large effect size (d = 0.8). Physical function outcomes improved only in GYM (all P  < 0.05). Conclusions Older adults with obesity transitioning from supervised gym-based to unsupervised home-based exercise face both supportive and challenging experiences. While accessibility and accountability enhanced their engagement, some participants faced difficulties related to limited equipment and digital support, emphasising areas for improvement in home-based exercise interventions. Home-based exercise may be effective for supporting dietary weight loss, but further research is needed to determine if there are any beneficial effects on physical function. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12618001146280; date of registration: 12/07/2018.

IntroductionThe bone-specific physical activity questionnaire (BPAQ) provides a bone-relevant index of physical activity participation according to the mechanical loads experienced across the life span. Materials and methodsWe aimed to examine relationships between historical bone-relevant physical activity and pQCT-derived parameters of bone strength. We recruited 532 healthy volunteers (277 males, 255 females) across a broad age range (4–97 years). Peripheral quantitative computed tomography (XCT-3000, Stratec, Germany) was used to examine volumetric bone density, area, and strength indices of the non-dominant tibia and radius. Exercise loading history from birth was determined using the past BPAQ (pBPAQ) score. Pearson correlation analysis was used to examine relationships between pBPAQ scores and pQCT parameters.ResultsIndependent of sex, pBPAQ scores were associated with total density at the 38% and 66% tibial sites and the 66% radial site (r = 0.145–0.261, p ˂ 0.05), total area at the 38% tibial site and 4% and 66% radial sites (r = 0.129–0.156, p ˂ 0.05), and strength indices at all measured sites (r = 0.123–0.234, p < 0.05).ConclusionWe conclude that, independent of sex, historical bone-relevant physical activity is associated with pQCT-derived indices of bone strength, indicating that pBPAQ captures the characteristics of bone loading history that are likely to be relevant adaptive stimuli. A larger sample is required to examine the influence of age on this relationship.

IntroductionNovel strategies are needed to address the rising burden of osteoporosis and fragility fractures. High-intensity resistance and impact (HiRIT) exercise has shown benefit in improving bone density in postmenopausal women with osteoporosis/osteopenia. Whether HiRIT can enhance the therapeutic effects of osteoporosis pharmacotherapy has not been established. ROLEX-DUO is a randomised controlled trial designed to assess the efficacy of romosozumab on various bone and muscle outcomes in combination with different exercise interventions in women with postmenopausal osteoporosis/osteopenia.Methods and analysisROLEX-DUO is an 8-month randomised placebo-controlled trial conducted at two tertiary referral centres for patients with osteoporosis/osteopenia in Sydney, New South Wales, Australia. The study is implementing the combination of romosozumab or placebo with different forms of exercise in postmenopausal women with osteoporosis/osteopenia without recent fragility fracture (n=102). Eligible women will be randomised 1:1:1 into one of three groups: (1) romosozumab with supervised HiRIT, (2) romosozumab with unsupervised low-intensity exercise or (3) placebo with unsupervised low-intensity exercise. Co-primary outcomes are the mean percentage change in lumbar spine bone mineral density (BMD), and mean change in five times sit-to-stand test performance (seconds) at 8 months. Secondary/exploratory outcomes include BMD changes at the femoral neck, total hip and distal radius, three-dimensional dual-energy X-ray absorptiometry (DXA) hip outcomes, DXA-derived lean and fat mass, serum markers of bone turnover (procollagen type 1 peptide, C-telopeptide of type 1 collagen) and bone biomarkers (dickkopf-1), serum extracellular vesicle analyses, 36-Item Short Form Survey (SF-36) quality-of-life scores, Menopause-Specific Quality Of Life (MENQOL) Questionnaire menopause symptom burden scores, number of falls and fractures. Mixed-effects models will be performed to compare longitudinal outcome results between groups using intention-to-treat analysis.Ethics and disseminationThe trial was approved by the Northern Sydney Local Health District Human Research Ethics Committee (2022/ETH01794, protocol V.8, dated 03 July 2024). Participants will provide written informed consent prior to inclusion. Findings will be disseminated via peer-reviewed journals, scientific conferences and summary reports to funding bodies.Trial registration numberACTRN12623000867695.

This paper is the first of a three-part series that investigates the architecture of cancellous (‘spongy’) bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is widely known to be highly sensitive to its mechanical environment, and has previously been used to infer locomotor biomechanics in extinct tetrapod vertebrates, especially primates. Despite great promise, cancellous bone architecture has remained little utilized for investigating locomotion in many other extinct vertebrate groups, such as dinosaurs. Documentation and quantification of architectural patterns across a whole bone, and across multiple bones, can provide much information on cancellous bone architectural patterns and variation across species. Additionally, this also lends itself to analysis of the musculoskeletal biomechanical factors involved in a direct, mechanistic fashion. On this premise, computed tomographic and image analysis techniques were used to describe and analyse the three-dimensional architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs for the first time. A comprehensive survey across many extant and extinct species is produced, identifying several patterns of similarity and contrast between groups. For instance, more stemward non-avian theropods (e.g. ceratosaurs and tyrannosaurids) exhibit cancellous bone architectures more comparable to that present in humans, whereas species more closely related to birds (e.g. paravians) exhibit architectural patterns bearing greater similarity to those of extant birds. Many of the observed patterns may be linked to particular aspects of locomotor biomechanics, such as the degree of hip or knee flexion during stance and gait. A further important observation is the abundance of markedly oblique trabeculae in the diaphyses of the femur and tibia of birds, which in large species produces spiralling patterns along the endosteal surface. Not only do these observations provide new insight into theropod anatomy and behaviour, they also provide the foundation for mechanistic testing of locomotor hypotheses via musculoskeletal biomechanical modelling.