Effects of ethnic density on the risk of compulsory psychiatric admission for individuals attending secondary care mental health services: evidence from a large-scale study in England.

BACKGROUND: Black, Asian and minority ethnicity groups may experience better health outcomes when living in areas of high own-group ethnic density - the so-called 'ethnic density' hypothesis. We tested this hypothesis for the treatment outcome of compulsory admission. METHODS: Data from the 2010-2011 Mental Health Minimum Dataset (N = 1 053 617) was linked to the 2011 Census and 2010 Index of Multiple Deprivation. Own-group ethnic density was calculated by dividing the number of residents per ethnic group for each lower layer super output area (LSOA) in the Census by the LSOA total population. Multilevel modelling estimated the effect of own-group ethnic density on the risk of compulsory admission by ethnic group (White British, White other, Black, Asian and mixed), accounting for patient characteristics (age and gender), area-level deprivation and population density. RESULTS: Asian and White British patients experienced a reduced risk of compulsory admission when living in the areas of high own-group ethnic density [odds ratios (OR) 0.97, 95% credible interval (CI) 0.95-0.99 and 0.94, 95% CI 0.93-0.95, respectively], whereas White minority patients were at increased risk when living in neighbourhoods of higher own-group ethnic concentration (OR 1.18, 95% CI 1.11-1.26). Higher levels of own-group ethnic density were associated with an increased risk of compulsory admission for mixed-ethnicity patients, but only when deprivation and population density were excluded from the model. Neighbourhood-level concentration of own-group ethnicity for Black patients did not influence the risk of compulsory admission. CONCLUSIONS: We found only minimal support for the ethnic density hypothesis for the treatment outcome of compulsory admission to under the Mental Health Act.

A cluster randomised controlled trial to assess the effectiveness of a multi-strategy sustainability intervention on teachers' sustained implementation of classroom physical activity breaks (energisers): study protocol.

BACKGROUND: Governments internationally have invested hugely in the implementation and scale-up of school-based physical activity interventions, but have little evidence of how to best sustain these interventions once active implementation support ceases. This study will assess the effectiveness of a multi-strategy sustainability intervention on classroom teachers' sustainment of energisers (short 3-5 min physical activity breaks during class-time) scheduled across the school day from baseline to 12 and 24-month follow-up. METHODS: A cluster randomised controlled trial will be conducted in 50 primary schools within the Hunter New England, Illawarra Shoalhaven, Murrumbidgee and Northern New South Wales (NSW) Local Health Districts of NSW Australia. Schools will be randomly allocated to receive either usual support or the multi-strategy sustainability intervention that includes: centralised technical assistance from a trained project officer; formal commitment and mandated change obtained from school principals; training in-school champions; reminders for teachers; educational materials provided to teachers; capturing and sharing local knowledge; and engagement of parents, carers and the wider school community. The primary trial outcome will be measured via a teacher logbook to determine the between-group difference in the change in mean minutes of energisers scheduled across the school day at 12 and 24-month follow-up compared to baseline. Analyses will be performed using an intention to treat framework. Linear mixed models will be used to assess intervention effects on the primary outcome at both follow-up periods. DISCUSSION: This study will be one of the first randomised controlled trials to examine the impact of a multi-strategy sustainability intervention to support schools' sustainment of a physical activity intervention. The proposed research will generate new evidence needed for the partnering organisations to protect their considerable investments to date in physical activity promotion in this setting and will provide seminal evidence for the field globally. TRIAL REGISTRATION: ACTRN12620000372987 version 1 registered 17th March 2020. Version 3 (current version) updated 4th August 2023.

Is social media use associated with children's well-being? Results from the UK Household Longitudinal Study.

INTRODUCTION: There are concerns about young people's increasing use of social media and the effects this has on overall life satisfaction. Establishing the significance of social media use requires researchers to take simultaneous account of other factors that might be influential and it is essential to adopt a longitudinal perspective to investigate temporal patterns. METHOD: Measures of happiness for children aged 10-15 from 7 waves of the UK Household Longitudinal Study were examined (n = 7596). Multilevel models were used to assess the relative association between these measures, children's social media use and individual, household and community characteristics. RESULTS: High use of social media was found to be significantly associated with change in happiness scores but was not associated with worsening life satisfaction trajectories. The most consistent factor was gender, with girls experiencing the largest decline in happiness between two time points (0.18 points) and being more likely to have a worsening trajectory over time (OR 1.77, 95% CI 1.36-2.32). Parental mental health, household support and household income were also important. CONCLUSION: Moderate use of social media does not play an important role in shaping children's life satisfaction. Higher levels of use is associated with lower levels of happiness, especially for girls but more research is needed to understand how this technology is being used. As well as focusing on high levels of social media use, policy makers should also concentrate on particular demographic groupings and factors affecting the social fabric of the households in which children grow up.

Training and match volume and injury in adolescents playing multiple contact team sports: A prospective cohort study.

Training and competition loads have emerged as valuable injury risk factors but very few studies have explored injury outcomes in adolescent athletes. The aims of this study were to describe injuries and to explore the relationship between training and match load volumes and injury in adolescent athletes participating in multiple contact team sports. One hundred and three male youth rugby athletes aged 14-16 years from 8 rugby union teams were prospectively monitored during a season for weekly training and match volumes and injuries. The relationship between volume and injury was explored by comparing the weekly volume in the week prior to an injury vs weeks without injury. There were 83 time-loss injuries in 58 athletes (62%). Overall injury incidence was 18.5 per 1000 player-hours. Mean weekly injury prevalence was 27% (95% CI 25-30). Average weekly volume was 5.4 (2.2) hours comprising 1.4 (1) match hours and 4 (2.6) training hours. Compared with weeks without injury, weeks prior to an injury had higher match volumes (110 [57] min vs 83 [59] min, P < 0.001). Poisson regression demonstrated that match volume was a predictor of injury with an odds ratio of 1.41 (P = 0.001). The contribution of match volumes to injury risk and the relatively high injury burden in these athletes may be profound. Very high match volumes are unlikely to be in the best interests of young athletes and could be avoided with a systematic approach to load management and athlete development.

A realist approach to the evaluation of complex mental health interventions.

Conventional approaches to evidence that prioritise randomised controlled trials appear increasingly inadequate for the evaluation of complex mental health interventions. By focusing on causal mechanisms and understanding the complex interactions between interventions, patients and contexts, realist approaches offer a productive alternative. Although the approaches might be combined, substantial barriers remain.Declaration of interestAll authors had financial support from the National Institute for Health Research Health Services and Delivery Research Programme while completing this work. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the National Health Service, the National Institute for Health Research, the Medical Research Council, Central Commissioning Facility, National Institute for Health Research Evaluation, Trials and Studies Coordinating Centre, the Health Services and Delivery Research Programme or the Department of Health. S.P.S. is part funded by Collaboration for Leadership in Applied Health Research and Care West Midlands. K.B. is editor of the British Journal of Psychiatry.

Validity and Reliability of a Submaximal Intermittent Running Test in Elite Australian Football Players.

Veugelers, KR, Naughton, GA, Duncan, CS, Burgess, DJ, and Graham, SR. Validity and reliability of a submaximal intermittent running test in elite Australian football players. J Strength Cond Res 30(12): 3347-3353, 2016-The aim of this article was to determine the validity and reliability of a submaximal intermittent running (SIR) test in elite Australian rules football (ARF) players. Heart rate (HR) responses of 38 elite ARF players to both the SIR and the yo-yo intermittent recovery 2 (YYIR2) tests were compared over 2 trials. Linear regression analysis was used to examine the relationship between SIR test HR responses and YYIR2 test performance. Heart rate responses of 25 elite ARF players to the SIR test were monitored over 3 trials. Day-to-day reliability was determined using intraclass correlation coefficient (ICC), typical error of measurement, coefficient of variation (CV), and smallest worthwhile change. Large inverse correlations were reported between 2-, 3-, and 4-minute HR during the SIR test and YYIR2 test distance (r = -0.58 to -0.61, p < 0.01). Heart rate recovery after 2 and 3 minutes of the SIR test was moderately correlated to YYIR2 distance (r = 0.32-0.35, p ≤ 0.05). Strong correlations for ICC (r = 0.90-0.97) and low CV (1.3-9.2%) were reported for all HR variables. Monitoring HR during the SIR test is a valid and reliable indicator of YYIR2 test performance in elite ARF players. These findings support the use of the SIR test as a regular and non-fatiguing indicator of intermittent running capacity.

GPS and Injury Prevention in Professional Soccer.

This study investigated the relationship between GPS variables measured in training and gameplay and injury occurrences in professional soccer. Nineteen professional soccer players competing in the Australian Hyundai A-League were monitored for 1 entire season using 5 Hz Global Positioning System (GPS) units (SPI-Pro GPSports) in training sessions and preseason games. The measurements obtained were total distance, high-intensity running distance, very-high-intensity running distance, new body load, and meters per minute. Noncontact soft tissue injuries were documented throughout the season. Players' seasons were averaged over 1- and 4-week blocks according to when injuries occurred. These blocks were compared with each other and with players' seasonal averages. Players performed significantly higher meters per minute in the weeks preceding an injury compared with their seasonal averages (+9.6 and +7.4% for 1- and 4-week blocks, respectively) (p < 0.01), indicating an increase in training and gameplay intensity leading up to injuries. Furthermore, injury blocks showed significantly lower average new body load compared with seasonal averages (-15.4 and -9.0% for 1- and 4-week blocks, respectively) (p < 0.01 and p = 0.01). Periods of relative underpreparedness could potentially leave players unable to cope with intense bouts of high-intensity efforts during competitive matches. Although limited by Fédération Internationale de Football Association regulations, the results of this study isolated 2 variables predicting soft tissue injuries for coaches and sports scientists to consider when planning and monitoring training.

Movement analysis of Australian national league soccer players using global positioning system technology.

Player activity profiles of match play provide valuable information for optimal athlete training prescriptions, competition strategies, and managing load and recovery and are currently lacking in elite Australian-league (A-League) soccer. The aims of the study were, therefore, to (a) determine match activity profiles for elite A-League soccer players and make match-half and positional comparisons and (b) examine the effect of situational factors including evolving match status (drawing, winning, or losing) and goals being scored and conceded on selected match activity profile variables. Global positioning system tracking devices were used to determine activity profiles of 19 elite male adult soccer players during 8 preseason matches (n = 95 files). Total distance, average speed, high-intensity running (HIR) distance, and very high-intensity running distance decreased from the first to the second half by 7.92, 9.47, 10.10, and 10.99%, respectively. Midfielders covered 11.69% more total distance, 28.08% more HIR distance, and had a 10.93% higher average speed than defenders (p ≤ 0.05; d = 1.90, 1.03, and 1.83, respectively). Attackers performed 27.50 and 30.24% less medium accelerations than defenders and midfielders, respectively (p < 0.01; d = 1.54, and 1.73). When the team was winning, average speed was 4.17% lower than when the team was drawing (p ≤ 0.05, d = 0.32). Scoring or conceding goals did not appear to affect HIR. This study adds to limited knowledge of match demands in elite A-League soccer. The match activity profiles provide descriptive benchmarks that could be used to make comparisons with other elite level soccer populations while also providing a framework for game-specific training prescription, competition strategy, and load management. The generalization that defenders experience a relatively lower match load may be questionable given their relatively high acceleration and deceleration demands.

Perceived load, fatigue and recovery responses during congested and non-congested micro-cycles in international football tournaments.

OBJECTIVES: To describe the perceived load, fatigue and recovery profiles during congested and non-congested schedules in international football tournaments. DESIGN: Retrospective single-cohort observational study. METHODS: Internal load (session-rating of perceived exertion [s-RPE]) and perceived ratings of fatigue, muscle soreness, psychological status, sleep quality, and sleep duration were recorded daily from 37 national team footballers during the competition phase of 3 international tournaments. ANOVA and Effect Size (ES) analyses compared individualised internal load and perceived response profiles between congested and non-congested acute 2-match schedules. Conditions included Acute Congestion (≤4 days between two matches), Non-Congestion (>4 days between two matches), Single-Match, and No-Match. RESULTS: Significantly higher s-RPE match loads (p < 0.001) within the single- and multi-match conditions resulted in significantly worsened (p < 0.05) subjective ratings of perceived fatigue, muscle soreness and sleep duration in the 24-48 h post-match. Internal load profiles were not different between the Acute-Congestion or Non-congestion conditions (p > 0.05); though Acute-Congestion had significantly worsened pre-match subjective ratings compared to Non-Congestion on both MD1 (p = 0.040; ES = 0.94) and MD2 (p = 0.033; ES = 0.94). However, between-match differences in Acute-Congestion showed no further impairments in perceived response between the first and second matches (p > 0.05). CONCLUSIONS: During international tournaments, internal load and perceived fatigue/recovery profiles are largely determined by their exposure (or lack thereof) to match-play. Periods of acute match congestion impaired players pre-match perceived status when compared to non-congested microcycles. However, acute match congestion does not appear to exacerbate players post-match fatigue/recovery response within the context of international football tournaments.

Moving beyond randomized controlled trials in the evaluation of compulsory community treatment.

Compulsory community treatment for people with severe mental illness remains controversial due to conflicting research evidence. Recently, there have been challenges to the conventional view that trial-based evidence should take precedence. This paper adds to these challenges in three ways. First, it emphasizes the need for critiques of trials to engage with conceptual and not just technical issues. Second, it develops a critique of trials centred on both how we can have knowledge and what it is we can have knowledge of. Third, it uses this critique to develop a research strategy that capitalizes on the information in large-scale datasets.

Transitioning from club to national teams: Training and match load profiles of international footballers.

OBJECTIVES: To quantify and profile the training and match loads of international footballers as they transition from club-to-camp-to-tournament contexts during multiple international tournaments. DESIGN: Retrospective single-cohort observational study. METHODS: External (session duration and count) and internal (session Rating of Perceived Exertion [s-RPE]) load data of all outfield players from the same national team were compared between club, pre-tournament camp and initial tournament phases of 3 recent international competitions. Further, load profiles were compared between each phase based on the acute:chronic (A/C) ratio using a 7 to 21-day ratio. RESULTS: Moderate-to-large effect sizes existed for increased number of sessions (ES=1.92; 90% CI: 1.56, 2.27) and s-RPE training load (ES=1.16; 0.84, 1.48) from club to camp. Conversely, transitioning from camp-to-tournament showed very large effects for decreased number of training sessions (ES=-3.17; -3.47, -2.86) and s-RPE training load (ES=-2.05; -2.35, -1.75), alongside increased number of matches (ES=1.87; 1.55, 2.18) and s-RPE match load (ES=1.57; 1.25, 1.89). Consequently, a moderate effect was evident for increased A/C ratio during the club-to-camp transition (ES=1.02; 0.70, 1.33), while a moderate decrease in the A/C ratio occurred during the tournament (ES=-0.76; -1.06, -0.46). CONCLUSIONS: International footballers showed expected increased training load when entering into pre-tournament camps, predominately via increased number of training sessions. Subsequent reductions in training volume coincide with increased match volume, though total load decreases. Such profiles provide insight into load accumulation transitioning from club to national teams in international footballers.

Supported housing programs for persons with serious mental illness in rural northern communities: a mixed method evaluation.

BACKGROUND: During the past two decades, consumers, providers and policy makers have recognized the role of supported housing intervention for persons diagnosed with serious mental illness (SMI) to be able to live independently in the community. Much of supported housing research to date, however, has been conducted in large urban centers rather than northern and rural communities. Northern conditional and contextual issues such as rural poverty, lack of accessible mental health services, small or non-existing housing markets, lack of a continuum of support or housing services, and in some communities, a poor quality of housing challenge the viability of effective supported housing services. The current research proposal aims to describe and evaluate the processes and outcomes of supported housing programs for persons living with SMI in northern and rural communities from the perspective of clients, their families, and community providers. METHODS: This research will use a mixed method design guided by participatory action research. The study will be conducted over two years, in four stages. Stage I will involve setting up the research in each of the four northern sites. In Stage II a descriptive cross-sectional survey will be used to obtain information about the three client outcomes: housing history, quality of life and housing preference. In Stage III two participatory action strategies, focus groups and photo-voice, will be used to explore perceptions of supported housing services. In the last stage findings from the study will be re-presented to the participants, as well as other key community individuals in order to translate them into policy. CONCLUSION: Supported housing intervention is a core feature of mental health care, and it requires evaluation. The lack of research in northern and rural SMI populations heightens the relevance of research findings for health service planning. The inclusion of multiple stakeholder groups, using a variety of data collection approaches, contributes to a comprehensive, systems-level examination of supported housing in smaller communities. It is anticipated that the study's findings will not only have utility across Ontario, but also Canada.

Monitoring loads and non-contact injury during the transition from club to National team prior to an international football tournament: A case study of the 2014 FIFA World Cup and 2015 Asia Cup.

OBJECTIVES: Injured and non-injured national team footballers were compared for external and internal loads during transition from club to National team training camp. DESIGN: Prospective Case Study. METHODS: Load and injury data were collected from the same National team prior to and during training camps of 2 tournaments; World (n=17) and Asian Cups (n=16). External (number sessions) and internal (s-RPE) loads were collected 4-weeks prior to and during camps. The acute:chronic load ratio was calculated for the first week of camp based on the mean of previous 4-weeks. Respective loads and ratios were compared between injured and non-injured players for non-contact injuries occurring during camp. RESULTS: Seven non-contact injuries occurred during World Cup camp and 1 during Asian Cup (preventing statistical analyses). Small-to-moderate effect sizes were found for lower chronic internal loads (ES=0.57; 90% CI: 0.39-1.08) and higher acute:chronic ratio (ES=0.45; 90% CI: 0.31-0.87) for injured compared to non-injured players. Moderate-large effects (ES=0.83; 90% CI: 0.56-1.60) were evident for increased acute:chronic ratio for number of sessions in injured compared to non-injured players. However, small-moderate effect sizes were present for lower chronic training and match loads (ES=0.55; 90% CI: 0.38-1.06) in injured players prior to the World Cup camp, alongside an increased number of sessions in week 1 of camp (ES=0.47; 90% CI: 0.33-0.91). CONCLUSIONS: Players incurring non-contact injury during training camp prior to an international tournament performed less prior chronic external and internal load and a concomitant higher relative increase in camp, thus representing a practical marker to monitor in national teams.

Evaluating the effects of community treatment orders (CTOs) in England using the Mental Health Services Dataset (MHSDS): protocol for a national, population-based study.

INTRODUCTION: Supervised community treatment (SCT) for people with serious mental disorders has become accepted practice in many countries around the world. In England, SCT was adopted in 2008 in the form of community treatment orders (CTOs). CTOs have been used more than expected, with significant variations between people and places. There is conflicting evidence about the effectiveness of SCT; studies based on randomised controlled trials (RCTs) have suggested few positive impacts, while those employing observational designs have been more favourable. Robust population-based studies are needed, because of the ethical challenges of undertaking further RCTs and because variation across previous studies may reflect the effects of sociospatial context on SCT outcomes. We aim to examine spatial and temporal variation in the use, effectiveness and cost of CTOs in England through the analysis of routine administrative data. METHODS AND ANALYSIS: Four years of data from the Mental Health Services Dataset (MHSDS) will be analysed using multilevel models. Models based on all patients eligible for CTOs will be used to explore variation in their use. A subset of CTO-eligible patients comprising a treatment group (CTO patients) and a matched control group (non-CTO patients) will be used to examine variation in the association between CTO use and study outcomes. Primary outcome will be total time in hospital. Secondary outcomes will include time to first readmission and mortality. Outputs from these models will be used to populate predictive models of healthcare resource use. ETHICS AND DISSEMINATION: Ethical approval has been granted by the National Health Service Data Access and Advisory Group and Warwick University. To ensure patient confidentiality and to meet data governance requirements, analyses will be carried out in a secure microdata laboratory using de-identified data. Study findings will be disseminated through academic channels and shared with mental health policy-makers and other stakeholders.

Locating Carper's aesthetic pattern of knowing within contemporary nursing evidence, praxis and theory.

Carper's (1978) seminal work has been used in nursing education for many years as a method for introducing students to the multitude of ways of knowing that support nursing practice. This manuscript focuses on the aesthetic pattern of knowing and the ongoing debate in nursing literature surrounding aesthetics, evidence and nursing practice. Writers will describe and critique a strategy used to introduce first year undergraduate nursing students to this pattern of knowing. The implications of the critique of the project and the ongoing debate in relation to Carper's (1978) work, evidenced based practice and nursing praxis are discussed.

Variation in compulsory psychiatric inpatient admission in England: a cross-classified, multilevel analysis.

BACKGROUND: The increasing rate of compulsory admission to psychiatric inpatient beds in England is worrying. Studying variation between places and services could be key to identifying targets for interventions to reverse this trend. We modelled spatial variation in compulsory admissions in England using national patient-level data and quantified the extent to which patient, local-area, and service-setting characteristics accounted for this variation. METHODS: This study is a cross-sectional, multilevel analysis of the 2010-11 Mental Health Minimum Data Set (MHMDS). Data from eight provider trusts were excluded, including three independent provider trusts that lacked spatial identification codes. We excluded patients detained under sections of the Mental Health Act concerned only with conveyance to, or assessment in, a registered Place of Safety, or for short-term (≤72 h) assessment only, as these do not in themselves necessarily mean that the person will be admitted to an inpatient mental health bed. MHMDS contained reasonably complete data for a limited number of patient characteristics, namely age, sex, and ethnicity; however, several patient-level variables could not be included in our analysis because of high levels of missing data. Multilevel models were applied with MLwiN to estimate variation in compulsory admission, starting with null (unconditional) models that partitioned total variance in compulsory admission between each level in the model. The primary outcome was compulsory admission to a psychiatric inpatient bed, compared with people admitted voluntarily or receiving only community-based care. FINDINGS: Data were available for 1 238 188 patients, covering 64 National Health Service provider trusts (93%) and 31 865 census lower super output areas (LSOAs; 98%). 7·5% and 5·6% of the variance in compulsory admission occurred at LSOA level and provider trust levels, respectively, after adjusting for patient characteristics. Black patients were almost three times more likely to be admitted compulsorily than were white patients (odds ratio [OR] 2·94, 95% CI 2·90-2·98). Compulsory admission was greater in more deprived areas (OR 1·22, 1·18-1·27) and in areas with more non-white residents (OR 1·51, 1·43-1·59), after adjusting for confounders. INTERPRETATION: Rates of compulsory admission to inpatient psychiatric beds vary significantly between local areas and services, independent of patient, area, and service characteristics. Compulsory admission rates seem to reflect local factors, especially socioeconomic and ethnic population composition. Understanding how these factors condition access to, and use of, mental health care is likely to be important for developing interventions to reduce compulsion. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme.

Themes in British health geography at the end of the century: a review of published research 1998-2000.

This paper provides a succinct overview of some recent trends in geography of health in Britain since 1998. We consider how the research we have reviewed illuminates the relationships between geographies of health and three fundamental processes which are widely recognized as being important for contemporary human geography as a whole: globalization, urbanization and polarization. We also consider the contribution of health geography to agendas in cultural geography agenda which we refer to here as 'geographies of imagination'. These perspectives all relate to dynamic and diverse processes operating in Britain and throughout the world. We explore how health geography is responding to change, and what the agenda for future research will be. By considering these themes, we also seek to show how the geography of health is contributing to a wider discourse, shared to some extent in human geography as a whole, and we discuss the themes which are likely to feature in the future health geography research agenda.

Bone mineral density in adolescent female athletes: relationship to exercise type and muscle strength.

PURPOSE: This study investigated the influence of different exercise types and differences in anatomical distribution of mechanical loading patterns on bone mineral density (BMD) in elite female cyclists, runners, swimmers, triathletes, and controls (N = 15 per group). Associations between leg strength and BMD were also examined. METHODS: Areal BMD (g x cm(-2)) was assessed by duel-energy x-ray absorptiometry (DXA) (total body (TB), lumbar spine (LS), femoral neck (FN), legs, and arms). Right knee flexion and extension strength was measured using a Cybex Norm isokinetic dynamometer at 60 degrees x s(-1). RESULTS: Runners had significantly higher unadjusted TB, LS, FN, and leg BMD than controls (P < 0.05); higher TB, FN, and leg BMD than swimmers (P < 0.05); and greater leg BMD than cyclists (P < 0.05). Absolute knee extension strength was significantly (P < 0.01) correlated (0.33 < or = r < or = 0.44) with TB, FN, LS, and leg BMD for all groups combined. Weaker but still significant correlations (0.28 < or = r < or = 0.33) existed for normalized (per leg lean tissue mass) knee extension strength and all BMD sites, except FN BMD. There were no significant correlations between absolute or normalized knee flexion strength and any of the BMD variables. Absolute knee extension strength was entered as the second independent predictor for LS and leg BMD in stepwise multiple linear regression analysis (MLRA), accounting for increments of 4% and 12%, respectively, in total explained variation. CONCLUSION: We conclude that running, a weight bearing exercise, is associated with larger site-specific BMD than swimming or cycling, that the generalized anatomical distribution of loads in triathlon appears not to significantly enhance total body BMD status, and that knee extension strength is only a weak correlate and independent predictor of BMD in adolescent females.

Mid-femur geometry and biomechanical properties in 15- to 18-yr-old female athletes.

PURPOSE: Right-leg mid-femur geometry and biomechanical indices of bone strength were compared among elite cyclists (CYC), runners (RUN), swimmers (SWIM), triathletes (TRI), and controls (C)-10 subjects per group. METHODS: Bone cross-sectional areas (CSA), volumes (Vol), and cross-sectional moments of inertia (CSMI) were assessed by magnetic resonance imaging (MRI), and cortical volumetric bone density (volBMD) was determined as the quotient of DXA-derived bone mineral content (BMC) and MRI-derived cortical bone volume. Bone strength index (BSI) was calculated as the product of cortical volBMD and CSMI. RESULTS: RUN had higher (P < 0.05) size- (femur length and body mass) adjusted (ANCOVA) cortical CSA than C, SWIM, and CYC; and higher size, age, and years of sport-specific training- (YST) adjusted cortical CSA than SWIM and CYC. TRI had higher (P < 0.05) size-adjusted CSA than SWIM. SWIM and CYC had significantly larger (P < 0.05) size-adjusted medullary cavity CSA than RUN and TRI, and the difference between CYC and RUN persisted after additional adjustment for age and YST. RUN had significantly (P < 0.05) greater size-adjusted CSMI and BSI than C, SWIM, and CYC; and higher size, age, and YST-adjusted CSMI and BSI than SWIM and CYC. Mid-femur areal bone mineral density (BMD) was significantly (P < 0.05) higher for RUN compared with CYC only, but there were no other differences among groups for BMC, bone volumes, or volumetric total or cortical BMD. CONCLUSIONS: Running, a weight-bearing exercise, is associated with more favorable geometric and biomechanical characteristics in relation to bone strength, compared with the weight supported activities of swimming and cycling. Differences may reflect skeletal adaptations to the specific mechanical-loading patterns inherent in these sports.