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Physical activity (PA) may improve brain development, cognition, concentration and academic performance. In this prospective controlled intervention study, we increased the level of PA in 338 children aged 6&ndash, 8 years at study start, from the Swedish standard of 60 min per week to 200 min per week (40 min daily). The intervention continued in all nine compulsory school years until the students graduated between 2007&ndash, 2012. All other 689,881 Swedish children who graduated the same years were included as a control group. We registered at graduation eligibility rate for upper secondary school and the final grade score (from 0 to 320 grade points). We also registered the same end points in the 295 students in the index school and in all other 471,926 Swedish students who graduated in 2003&ndash, 2006, that is, those who graduated before the intervention study started. Before the intervention, academic performance was similar among children in the index school as for all other Swedish boys and girls. With the intervention, the eligibility rate increased for boys in the index school by 7.3 percentage points and the mean grade scores by 13.3 points. This should be compared with a decrease of 0.8 percentage points in eligibility rate and an increase by 2.7 points in grade score in other Swedish boys. No changes were seen for intervention girls, neither in eligibility rates or grade scores. By introducing daily school-based PA in compulsory school, more boys would probably reach the eligibility rate for higher education.

Background Physical activity (PA) in childhood is associated with musculoskeletal benefits while the effect on fracture risk is yet to be determined. The aim of this study was to evaluate whether extension of a PA intervention leads to improvement in musculoskeletal traits with an accompanied reduced fracture risk. We hypothesized that the PA program would have beneficial effects in both sexes, but more so in girls since they tend to be less physically active than boys during this time frame. Methods In one elementary school we increased physical education (PE) from 60 to 200 min per school week and followed 65 girls and 93 boys from a mean age of 7 years until a mean age of 15 years. Thirty-nine girls and 37 boys in three other schools continued with 60 min of PE per week during the same years and served as controls. We measured bone mineral content (BMC), areal bone mineral density (aBMD), and bone area annually with dual energy X-ray absorptiometry, and leg muscle strength with a computerized dynamometer. In 3534 children within the same PE program (1339 in the intervention and 2195 in the control group) we registered incident fractures during the 8-year study period and estimated annual sex-specific fracture incidence rate ratios (IRRs). Results Girls in the intervention group annually gained more total body less head aBMD, spine aBMD (p < 0.01), femoral neck BMC (p < 0.05), lumbar vertebrae size (p < 0.05), and knee flexion strength (p < 0.05) than girls in the control cohort. In boys we found no group differences. There was an inverse correlation between number of years with extra PE and the annual IRR of sustaining fractures in both girls (r = − 0.90 (95% CI − 0.98 to − 0.51); p < 0.001) and boys (r = − 0.74 (95% CI − 0.94 to − 0.02); p < 0.05). Conclusion In this 8-year pediatric school-based moderate exercise intervention program there is an inverse correlation in both sexes between annual IRR and each additional year of extra PA. A sub-cohort of girls in the intervention group had greater gains in bone mass, bone size, and muscle strength, which could possibly explain the inverse correlation between years within the PA program and fracture risk, while in boys the reason for the inverse correlation remains unknown. It should be noted that differences in unreported factors such as skeletal maturity status, diet, and spare time PA could confound our inferences. That is, true causality cannot be stated.

Transport infrastructure is closely linked to several sustainability issues of main policy relevance, and significant impacts on biodiversity as well as resource use and construction costs relate t ...

Aim: This study evaluated the musculoskeletal effects of increased physical activity on children, starting at six to nine years of age. Methods: In one school we increased the physical education of 72 girls and 100 boys to 200 minutes per week over seven years. In three other schools, 45 girls and 47 boys continued to receive 60 minutes per week. We measured areal bone mineral density (aBMD) with dual energy X-ray absorptiometry and muscle strength with computerised dynamometer at baseline and after seven years and tibial cortical thickness with peripheral quantitative computed tomography after seven years. Results: Girls in the intervention group gained 0.04 g/cm2 (0.01-0.08) more total spine aBMD (p

This 7.5-year prospective controlled exercise intervention study assessed if daily school physical activity (PA), from before to after puberty, improved musculoskeletal traits. There were 63 boys and 34 girls in the intervention group (40 min PA/day), and 26 boys and 17 girls in the control group (60 min PA/week). We measured musculoskeletal traits at the start and end of the study. The overall musculoskeletal effect of PA was also estimated by a composite score (mean Z-score of the lumbar spine bone mineral content (BMC), bone area (BA), total body lean mass (TBLM), calcaneal ultrasound (speed of sound (SOS)), and muscle strength (knee flexion peak torque)). We used analyses of covariance (ANCOVA) for group comparisons. Compared to the gender-matched control group, intervention boys reached higher gains in BMC, BA, muscle strength, as well as in the composite score, and intervention girls higher gains in BMC, BA, SOS, as well as in the composite score (all p &lt, 0.05, respectively). Our small sample study indicates that a daily school-based PA intervention program from Tanner stage 1 to 5 in both sexes is associated with greater bone mineral accrual, greater gain in bone size, and a greater gain in a musculoskeletal composite score for fractures.

ObjectivesWe examined whether daily physical activity (PA) during compulsory school encourages children to be more physically active during the intervention and 4 years after termination of the programme.MethodsThis prospective controlled intervention study followed the same 124 children (81 children in an intervention group and 43 controls) aged 7.7±0.6 (mean±SD) during a 7-year PA intervention and 4 years after the intervention when the children were 18.7±0.3 years old. The intervention included daily school physical education (PE) (200 min/week), whereas the controls continued with the Swedish standard of 60 min/week. Using a questionnaire, we gathered data about total PA, leisure time PA and sedentary activities (SA). Group comparisons are adjusted for age and gender, and data are provided as means with 95% CIs.ResultsAt baseline, we found similar duration of PA and SA between groups. After a mean of 7 years with intervention, the intervention group was more physically active than the controls (+4.5 (2.9 to 6.0) hours/week), whereas SA was similar (+0.6 (−2.5 to 3.9) hours/week). Four years beyond the intervention, the intervention group was still more physically active than the controls (2.7 (0.8 to 4.7) hours/week), and SA was still similar (−3.9 (−9.7 to 1.7) hours/week).ConclusionsIntervention with daily school PE throughout compulsory school is associated with higher duration of PA not only during the intervention but also 4 years after termination of the programme.

Objective: To determine if primary hand osteoarthritis (OA) is associated with abnormal bone and anthropometric traits. Methods: We used DXA to measure total body bone mineral density (BMD), femoral neck width (bone size) and total body lean and fat mass in 39 subjects with hand OA (primary DIP and/or CMC I) and 164 controls. Data are presented as mean Z-scores or Odds Ratios (OR) with 95% confidence intervals. Results: Women with hand OA had (compared to controls) higher BMD (0.5(0.1,0.9)) but similar bone size (-0.3(-0.8,0.2)), lean mass (0.3(-0.3,0.9)), fat mass (-0.1(-0.6,0.5)) and BMI (0.0(-0.6,0.6)). Men with hand OA had (compared to controls) similar BMD (-0.1(-0.7,0.6)), smaller bone size (-0.5(-1.1,-0.01)), lower lean mass (-0.6(-1.1,-0.04)), and similar fat mass (-0.2(-0.7,0.4)) and BMI -0.1(-0.6,0.6). In women, each SD higher BMD was associated with an OR of 1.8 (1.03, 3.3) for having hand OA. In men each SD smaller bone size was associated with an OR of 1.8 (1.02, 3.1) and each SD lower proportion of lean body mass with an OR of 1.9 (1.1, 3.3) for having hand OA. Conclusion: Women with primary DIP finger joint and/or CMC I joint OA have a phenotype with higher BMD while men with the disease have a smaller bone size and lower lean body mass.

Although knee osteoarthritis (OA) is common, its etiology is poorly understood. Specifically, it is not known whether knee OA is associated with abnormal anthropometric and musculoskeletal characteristics known to be associated with OA in general. We recently studied this topic for patients with hip arthritis; however, it is important to evaluate it for knee OA separately, because there are reports indicating that patients with primary OA in different joints may have a different phenotype.Do patients with primary knee OA have a phenotype with higher bone mineral density (BMD), higher body mass index (BMI), larger skeletal size, lower lean body mass, and higher fat content?We included 38 women and 74 men (mean age, 61 years; range, 34-85 years) with primary knee OA and 122 women and 121 men as control subjects. We used dual-energy x-ray absorptiometry to measure total body BMD (g/cm2), femoral neck width (cm), fat and lean mass (%), and BMI (kg/m2). Z scores were calculated for each individual. Data are presented as means with 95% confidence intervals.Women with knee OA had the following Z scores: total body BMD 0.8 (0.5-1.0); BMI 1.6 (1.1-2.0); femoral neck width 0.1 (-0.3 to 0.4); proportion of lean mass -1.0 (-1.5 to -0.6); and proportion of fat mass 1.0 (0.6-1.4). Men with knee OA had the following Z scores: total body BMD 0.5 (0.3-0.7); BMI 0.9 (0.6-1.1); femoral neck width 0.3 (0.1-0.7); proportion of lean mass -0.9 (-1.1 to -0.8); and proportion of fat mass 0.7 (0.5-0.9).Women and men with idiopathic knee OA have a phenotype with higher BMD, higher BMI, proportionally higher fat mass, and proportionally lower lean body mass. Men also have a larger skeletal size.A higher BMD may lead to stiffer bone, a higher BMI to a greater joint load, and a proportionally lower lean body (muscle) mass to lower joint-protective ability, and all trait deviations probably predispose for knee OA.

Aim: Physical activity (PA) has been associated with enhanced cognition, brain development and concentration. This study evaluated whether increased physical education (PE) improved academic achievement. Methods: We recruited 304 children (55% boys) from a Swedish school in Skane County in 1998-2002 when they were six to seven years of age and followed them through all nine mandatory school years. Their PE level was increased from 60 to 200 minutes per week, and their results were compared with 73 885 control children (51% boys) in the county who graduated in the same years and did the standard 60 minutes of PE per week. Their academic achievements were measured as their final grade scores and the proportion of students eligible for upper secondary school. Results: The eligibility for further education increased in the intervention boys by 6.8 percentage points and the mean grade score by 12.1 points, while in the control group as a whole, the eligibility rate decreased by 0.7 percentage points and the mean grade score increased by 1.7 points. No changes in eligibility rates or mean grade scores were seen in the intervention girls. Conclusion: Increasing weekly PE over nine years was associated with improved academic achievement in boys. (Less)

Aim: This study assessed whether a Swedish school-based exercise intervention programme could increase total physical activity. Methods: We followed up 228 children who started school in 1998-2000 seven years later, when they had reached a mean age of 14.8. The 152 children (59% boys) at the intervention school did 200 minutes of physical education per week during that period, and the 76 children (50% boys) in the three control schools did the standard 60 minutes. Questionnaires assessed the durations of total and leisure-time physical activity and screen-time activity at baseline and after five and seven years. Results: Physical activity and screen-time activity were similar between the two groups before the study started. The intervention group then achieved higher durations of total physical activity than the controls (p < 0.001) and these levels remained in the sex-specific evaluations. There were no differences between the groups in the durations of leisure-time activity (p 0.08-0.77) or screen-time activity (p 0.31-0.91). Conclusion: A school-based exercise intervention programme increased the total duration of physical activity in both sexes without any compensatory increase in screen-time activity. The findings contradict the activity-stat theory, which stated that the duration of physical activity in children is constant. (Less)

Objective: The aim of this study was to evaluate whether primary osteoarthritis (OA), independent of affected joint, is associated with a phenotype that is different from the phenotype in a normative cohort. Material and Methods: We included 274 patients with primary OA, 30 women and 32 men (mean age 66 years, range 42-84) with primary hip OA, 38 women and 74 men (mean age 61 years; range 34-85) with primary knee OA, 42 women and 19 men (men age 64 years, range 42-87) with primary ankle or foot OA and 20 women and 19 men (mean age 66 years, range 47-88) with primary hand or finger OA. Of all patients included with OA, 23% had hip OA, 41% knee OA, 22% ankle or foot OA and 14% hand or finger OA. Serving as references were 122 women and 118 men of the same ages who were population-based, included as a control cohort. We measured total body BMD (g/cm2) and proportion of fat and lean mass (%) with dual energy X-ray absorptiometry. Height, weight and BMI (kg/m2) were also assessed. We then calculated Z-scores (number of standard deviations difference from the mean value of the control cohort) in the OA patients and compared these between the groups. Results: Individuals with hand OA and controls had similar phenotype. Individuals with lower extremity OA, irrespective of the affected joint, had similar weight, BMI and BMD, but higher than in individuals with hand OA and controls (all p Conclusion: Individuals with primary OA in the lower extremity have a phenotype with higher BMD, higher BMI, proportionally higher fat content and lower lean body mass content. The different skeletal phenotypes in our patients with OA in the lower extremity and patients with hand OA indicate that separate pathophysiologic pathways may be responsible for primary OA in different joints

Background and Purpose: Cross-sectional studies have shown that patients with primary hip osteoarthritis (OA) have higher bone mineral density (BMD), higher BMI, lower lean body mass, and higher fat content. But it is unknown if this phenotype is found also in patients with knee OA and if it precedes OA or manifests as a result of the disease. Patients and Methods: We included 21 women and 18 men (mean age, 71 years; range, 48-85 years) with primary OA in all three knee compartments, 17 women and 56 men (mean age, 55 years; range, 34-74 years) with primary medial knee OA and 122 women and 121 men without OA as controls. We measured total body BMD (g/cm2), fat and lean mass (%) by dual energy X-ray absorptiometry and also registered height and weight to calculate BMI (kg/m2). Z-scores were calculated for each individual. Data are presented as means with 95% confidence intervals within brackets. Results: Individuals with primary OA in all three knee compartments had the following Z-scores: total body BMD 0.4 (0.0, 0.9); BMI 1.2 (0.7, 1.6); proportion of lean mass -0.6 (-1.1, -0.1); proportion of fat mass 0.4 (0.0, 1.8). Individuals with medial knee OA had the following Z-scores: total body BMD 0.4 (0.3, 0.6); BMI 1.1 (0.8, 1.4); proportion of lean mass -0.8 (-1.3, -0.9); proportion of fat mass 0.9 (0.7, 1.1). Interpretations: A phenotype with higher BMD, higher BMI, higher fat mass, and proportionally lower lean body mass is evident in individuals with primary OA in all three knee compartments and in patients with only medial knee OA.

In the present paper we combine two analytical frameworks in order to extend our understanding of how students reason about a socio-scientific issue, namely, nanomaterials in consumer products. Usi ...

Although hip osteoarthritis (OA) is common, its etiology is poorly understood. Specifically, it is not known whether hip OA is associated with abnormal relationships among the anthropometric and musculoskeletal characteristics that are associated with OA in general.We asked whether patients with primary hip OA have a phenotype with higher bone mineral density (BMD), higher BMI, larger skeletal size, lower lean body mass, and higher fat content.We included 30 women and 32 men (mean age, 66 years; range, 42-84 years) with primary hip OA and 96 women and 91 men as control subjects. Dual energy x-ray absorptiometry was used to measure total body BMD (g/cm(2)), femoral neck width (cm), fat and lean mass (%), and BMI (kg/m(2)). Z scores were calculated for each individual. Data are presented as means with 95% CI.Women with hip OA had the following Z scores: total body BMD 0.6 (0.3, 1.0); BMI 0.6 (0.2, 1.0); femoral neck width 0.2 (-0.6, 1.0); percent total body lean mass -0.9 (-1.2, -0.5); and percent total body fat mass 0.6 (0.2, 0.9). Men with hip OA had the following mean Z scores: total body BMD 0.5 (0.0, 1.0); BMI 0.8 (0.3, 1.3); femoral neck width 0.4 (0.01, 0.9); percent total body lean mass -0.8 (-1.1, -0.5); and percent total body fat mass 0.5 (0.2, 0.8).Women and men with idiopathic hip OA have a phenotype with higher BMD, higher BMI, proportionally higher fat mass, and proportionally lower lean body mass. Men also have a larger skeletal size.A higher BMD may lead to a stiffer bone and a proportionally lower lean body mass to lower joint-protective ability, both traits probably predisposing for hip OA.

Aims: Fallers and especially recurrent fallers are at high risk for injuries. The aim of this study was to evaluate fall epidemiology in older men with special attention to the influence of age, ethnicity and country of residence. Methods: 10,998 men aged 65 years or above recruited in Hong Kong, the United States (US) and Sweden were evaluated in a cross-sectional retrospective study design. Self-reported falls and fractures for the preceding 12 months were registered through questionnaires. Group comparisons were done by chi-square test or logistic regression. Results: The proportion of fallers among the total population was 16.5% in ages 65–69, 24.8% in ages 80–84 and 43.2% in ages above 90 ( P

SummaryPhysical training, if including specific different training modalities, reduces the fall risk in healthy community-dwelling older people, as does a home hazards modification programme. Vitamin D supplementation in older individuals with low levels of vitamin D, adjustment of psychotropic medication, and structured modification of multi-pharmacy are all drug-focused programmes that reduce the number of falls. Anti-slip shoe devices during icy conditions for older people who walk outdoors and multifaceted podiatry in patients with specific foot disability reduce the fall risk. First eye cataract surgery and pacemakers in patients with cardio-inhibitory carotid sinus hypersensitivity are surgical interventions that reduce the fall risk. Multi-factorial preventive programmes that include training, both individually designed and generally prescribed, also reduce the fall frequency. With this in mind, we ought to initiate fall preventive programmes in older people, especially in high- risk groups, to reduce the number of falls and fallers in society.

Summary The study investigates the effect of physical activity (PA) on a composite score for fracture risk in pre-pubertal children. Low PA in children is related to the composite score for fracture risk and the pre-pubertal years seem to be a period when PA positively affects the score. Introduction This study evaluates if PA in children is related to clustering of risk factors for fracture. Research questions are the following: (i) What is the effect of physical activity (PA) on single traits and a composite score for fracture risk? (ii) Could this score be used to identify the level of PA needed to reach beneficial effects? Methods This prospective population-based study included 269 children, aged 7–9 years at baseline while 246 attended the 2-year follow-up. We estimated duration of PA by questionnaires and measured traits that independently predict fractures. We then calculated gender specific Z-scores for each variable. The mean Z-score of all traits was used as a composite score for fracture risk. We tested correlation between duration of PA, each trait, and the composite score and group differences between children in different quartiles of PA. Results At baseline, we found no correlation between duration of PA and any of the traits or the composite score. At follow-up, we found a correlation between PA and the composite score. Physical activity had an effect on composite score, and children in the lowest quartiles of PA had unbeneficial composite score compared to children in the other quartiles. Conclusion Low PA in children is related to clustering of risk factors for fracture, and the pre-pubertal years seem to be a period when PA positively affects the composite score.

The aim of this study was to investigate the gut microbiota in preschool children with and without overweight and obesity. Twenty overweight or obese children and twenty children with BMI within the normal range (age: 4-5 years) were recruited from the south of Sweden. The gut microbiota was accessed by quantitative PCR (qPCR) and terminal restriction fragment length polymorphism and calprotectin was measured in feces. Liver enzymes were quantified in obese/overweight children. The concentration of the gram-negative family Enterobacteriaceae was significantly higher in the obese/overweight children (P = 0.036), whereas levels of Desulfovibrio and Akkermansia muciniphila-like bacteria were significantly lower in the obese/overweight children (P = 0.027 and P = 0.030, respectively). No significant differences were found in content of Lactobacillus, Bifidobacterium or the Bacteroides fragilis group. The diversity of the dominating bacterial community tended to be less diverse in the obese/overweight group, but the difference was not statistically significant. Concentration of Bifidobacterium was inversely correlated to alanine aminotransferase (ALT) in obese/overweight children. The fecal levels of calprotectin did not differ between the study groups. These findings indicate that the gut microbiota differed among preschool children with obesity/overweight compared with children with BMI within the normal range.

Aims: Animal studies indicate a role for 11 beta-hydroxysteroid dehydrogenase type 1 (HSD11B1) in the development of obesity. The association to glucose homeostasis is less clear. We investigated the relationship between HSD11B1 mRNA levels in adipose tissue and in skeletal muscle and anthropometric and metabolic measurements in humans with and without impaired glucose homeostasis. Methods: Twelve obese subjects with impaired glucose homeostasis (MetS+) and 12 obese controls (MetS-) received a Very Low Calorie Diet for 16 weeks and adipose tissue biopsies, blood samples and measurements were obtained. In a second cohort, skeletal muscle biopsies, blood samples and measurements were obtained from 18 subjects with type 2 diabetes (T2DM) and 17 subjects with normal glucose tolerance (NGT). Gene expression was measured by DNA microarray in both studies. Results: HSD11B1 mRNA levels were reduced during diet, and anthropometric measurements and metabolic parameters were associated with HSD11B1 mRNA levels in the MetS-group. However, in the MetS+ group these associations were lost or in opposite direction. This difference was also observed in skeletal muscle between T2DM and NGT. Conclusions: HSD11B1 mRNA levels are associated with metabolic parameters and anthropometric measurements in subjects with normal glucose homeostasis but not in subjects with impaired glucose homeostasis. (C) 2010 Elsevier Ireland Ltd. All rights reserved. (Less)

Undisplaced radial head and neck fractures are consistently described with no long-term deficits. The aim of this study was to evaluate specifically the long-term outcome of displaced Mason type I fractures, which have not previously described. Twenty women and twelve men, with a mean age of 46 years (range, 22-69 years) when they sustained a displaced Mason type I fracture, were reexamined at a mean of 21 years (range, 15-33 years) after injury. All were treated nonoperatively. Twenty-nine individuals had no subjective complaints, whereas three had occasional elbow pain. There was no objective impairment, and none had elbow osteoarthritis, defined as reduced joint space, whereas there was more radiographic degeneration in the formerly fractured elbow than in the uninjured elbow (85% vs 4%, P < .001). We conclude that the long-term results of nonoperatively treated displaced Mason type I fractures of the radial head and neck are predominantly favorable.

Ten girls and 13 boys with mean age 11 years when sustaining a fracture of the olecranon were examined at a mean of 19 years after the injury. Ten fractures were displaced less than 2 mm, three 2-3 mm, eight more than 3 mm and two were multifragmental. The treatment consisted of mobilization in three cases, plaster treatment in nine and open reduction and internal fixation in 11 cases. At follow-up, 21 children had no subjective complaints while two had occasional mild pain. The upper arm circumference was thinner in the former injured extremities than in the uninjured (P

Purpose: This 11-year prospective longitudinal study examined how a pre-pubertal pediatric bone mass scan predicts peak bone mass. Methods: We measured bone mineral content (BMC; g), bone mineral density (BMD; g/cm2) and bone area (cm2) in femoral neck, total body and lumbar spine by dual energy X-ray absorptiometry (DXA) in a population based cohort including 65 boys and 56 girls. At baseline all participants were pre-pubertal with a mean age of 8 years (range 6-9), they were re-measured at a mean 11 years (range 10-12) later. The participants were then mean 19 years (range 18-19), an age range that corresponds to peak bone mass in femoral neck in our population. We calculated individual BMC, BMD and bone size Z-scores, using all participants at each measurement as reference and evaluated correlations between the two measurements. Individual Z-scores were also stratified in quartiles to register movements between quartiles from pre-pubertal age to peak bone mass. Results: The correlation coefficients (r) between pre-pubertal and young adulthood measurements for femoral neck BMC, BMD and bone area varied between 0.37-0.65. The reached BMC value at age 8 years explained 42% of the variance in the BMC peak value, the corresponding values for BMD was 31% and bone area 14%. Among the participants with femoral neck BMD in the lowest childhood quartile, 52% had left this quartile at peak bone mass. A pediatric bone scan with a femoral neck BMD value in the lowest quartile had a sensitivity of 47% (95% CI 28, 66) and a specificity of 82% (95% CI 72, 89) to identify individuals who would remain in the lowest quartile at peak bone mass. Conclusions: The pre-pubertal femoral neck BMD explained only 31% of the variance in femoral neck peak bone mass. A pre-pubertal BMD scan in a population based sample has poor ability to predict individuals who are at risk of low peak bone mass.

The influence of pregnancy on bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry (DXA) in 73 women (mean age 29 years, range 20-44 years) postpartum. Fifty-five age-matched women served as controls. The influence of lactation was evaluated in 65 of the delivered women who were followed with repeated measurements, a mean of 4.5 +/- 0.1 and 11.5 +/- 0.1 months after the delivery. The influence of multiple pregnancies was evaluated in 39 premenopausal women (mean age 38 years, range 31-54 years) with a minimum of four pregnancies (range 4-7). Fifty-eight age-matched healthy premenopausal women with a maximum of two pregnancies (range 0-2) served as controls. Data are presented as mean +/- SEM. BMD data are adjusted for differences in total fat mass and total lean mass. Lumbar spine BMD was 7.6 +/- 0.1% and total body BMD 3.9 +/- 0.1% lower in women postpartum compared with controls (both p

Patients with hip and knee osteoarthritis (OA) have high bone mineral density (BMD) and high BMI. If the same accounts for patients with foot or ankle OA is unknown.We measured BMD and femoral neck (FN) width by dual-energy X-ray absorptiometry in 42 women and 19 men with idiopathic OA in the foot or ankle, and in 99 women and 82 men as controls.Women with OA had significant higher BMI than controls. Women with OA had higher BMI-adjusted BMD (p0.01) and smaller BMI-adjusted FN width (p0.01) than controls. Men with OA had higher BMI adjusted-BMD (p0.05) and smaller BMI-adjusted FN width (p0.01) than controls.Patients with OA in the foot or ankle have higher BMD and smaller bone size than being expected by their BMI. This phenotype may provide unfavourable forces across the joint and is hypothetically important for development of OA.

Objectives Recent evidence from the 7-year follow-up of the Pediatric Osteoporosis Prevention (POP) study indicates an inverse correlation between years of participation in a physical activity (PA) intervention and fracture risk in children. However, we could not see a statistically significant reduction in fracture risk, which urged for an extension of the intervention. Setting The study was conducted in 4 neighbouring elementary schools, where 1 school functioned as intervention school. Participants We included all children who began first grade in these 4 schools between 1998 and 2012. This resulted in 1339 children in the intervention group and 2195 children in the control group, all aged 6–8 years at the state of the study. Intervention We launched an 8-year intervention programme with 40 min of moderate PA per school day, while the controls continued with the Swedish national standard of 60 min of PA per week. Primary outcome measure We used the regional radiographic archive to register objectively verified fractures and we estimated annual fracture incidences and incidence rate ratios (IRRs). Results During the first year after initiation of the intervention, the fracture IRR was 1.65 (1.05 to 2.08) (mean 95% CI). For each year of the study, the fracture incidence rate in the control group compared with the intervention group increased by 15.7% (5.6% to 26.8%) (mean 95% CI). After 8 years, the IRR of fractures was 52% lower in the intervention group than in the control group (IRR 0.48 (0.25 to 0.91) (mean 95% CI))]. Conclusions Introduction of the school-based intervention programme is associated with a higher fracture risk in the intervention group during the first year followed by a gradual reduction, so that during the eighth year, the fracture risk was lower in the intervention group. Trial registration number NCT00633828.

The proportion of elderly in the society increases and fall frequency increases with advancing age. Many falls result in fractures and also soft tissue injuries, longstanding pain, functional impairment, reduced quality of life, increased mortality, and excess in healthcare costs. Due to the magnitude of these negative effects, a variety of single- and multicomponent fall-preventive intervention programs has been initiated.This review identifies programs that, in randomized controlled trials (RCTs), have been shown with fall-reductive effects.The most effective strategies in community-dwelling elderly include regular physical training with program that includes several different training modalities. Modification of the overall or patient-specific risk factor profile in home hazard modification program has been proven to decrease fall risk in community-living elderly. The elderly in the community benefit also from wearing antislip shoe devices when walking in icy conditions, from adjustment of psychotropic medication, and from structured modification of multipharmacy. If vitamin D levels in blood are low, supplementation is beneficial as is the first eye cataract surgery and pacemaker implantation in patients with cardioinhibitory carotid sinus hypersensitivity. In addition to modification of specific risk factors, generalized and individualized multifactorial preventive programs, all including some sort of physical training, have been found to decrease the fall risk. In summary, there is now strong evidence in the literature that structured fall-preventive programs in the elderly, especially in high-risk groups, are beneficial in reducing both the number of fallers and the number of falls in community.

Dual-energy X-ray absorptiometry hip scans of 1,760 population-based Caucasians, 599 girls and 642 boys aged 6-19 years and 270 women and 249 men aged 20-90 years, were analyzed with the hip structural analysis (HSA) software to present age- and sex-specific normative HSA data of the femoral neck (FN). Measured traits included bone mineral density (BMD), cross-sectional area (CSA), section modulus (Z), periosteal diameter (PD), endosteal diameter (ED), cortical thickness (CT), and cross-sectional moment of inertia (CSMI). When plotting the measured traits versus age, the curves increased with higher ages until statistically significant break points were reached, for all traits at age 17 in girls and age 19 in boys. After the break points, PD and ED increased with higher ages but, as ED increased more than PD, BMD and CT decreased significantly with higher ages. The decline in BMD was counteracted by the increase in bone size so that there was only a nonstatistically significant decrease in bone strength, estimated as Z and CSMI, from break point to age 90. The partial preservation of bone strength was more obvious in men than in women as the decline in BMD was higher in women than in men, while the expansion in PD was larger in men than in women. The sex difference in the normative FN bone strength data seems to be related to sex discrepancies in the development of both bone mass and geometrical parameters during both growth and adulthood.

Study design: A thematic review. Objectives: To evaluate if physical activity enhances muscle strength, improves balance, and reduces the fall frequency and the fracture incidence. Background: One of the major medical problems of today is the increasing incidence of fragility fractures. Muscle strength and fall is one of the major determinants of a fracture. If physical activity could increase muscle strength, improve balance and reduce the fall frequency, then training could be recommended as prevention for fractures. Methods: The review used Medline (Pub Med) and the search words exercise, physical activity, muscle, muscle strength, balance, falls, fractures Randomised controlled trials (RCT) were predominantly included, although this not is a systematic review. Results: The evidence that physical activity modifies the risk factors for fall is compelling, although RCT with fractures as end point are lacking. Physical activity is associated with improved muscle strength, co-ordination and balance. Physical training increases muscle strength also in octogenarians by up to 200 %, i.e. a much more pronounced effect than the corresponding increase in muscle volume or bone mass. There is also evidence that physical activity decrease the actual number of falls. Observational cohort and case-control studies imply that physical activity is associated with reduced hip fracture risk. If exercise reduces the number of vertebral fractures and other fragility fractures is less evaluated. Conclusions: Physical activity in older ages can be recommended to improve muscle strength and balance, to reduce the risk to fall and fractures, although the highest level of evidence - RCT with fracture as endpoint - is lacking. Keywords: exercise; muscle strength; muscle mass; fall; fractures; physical activity (Published online: 30 December 2008) Citation: Food & Nutrition Research 2008. DOI: 10.3402/fnr.v52i0.1920

Background: The incidence of fragility fractures has increased during the last half of the 1900?s. One important determinant of fractures is the bone mineral content (BMC) or bone mineral density (BMD), the amount of mineralised bone. If we could increase peak bone mass (the highest value of BMC reached during life) and/or decrease the age-related bone loss, we could possibly improve the skeletal resistance to fracture. Objective: This review evaluates the importance of exercise as a strategy to improve peak bone mass, including some aspects of nutrition. Design: Publications within the field were searched through Medline (PubMed) using the search words: exercise, physical activity, bone mass, bone mineral content, bone mineral density, BMC, BMD, skeletal structure and nutrition. We included studies dealing with exercise during growth and young adolescence. We preferably based our inferences on randomised controlled trials (RCT), which provide the highest level of evidence. Results: Exercise during growth increases peak bone mass. Moderate intensity exercise intervention programs are beneficial for the skeletal development during growth. Adequate nutrition must accompany the exercise to achieve the most beneficial skeletal effects by exercise. Conclusion: Exercise during growth seems to enhance the building of a stronger skeleton through a higher peak bone mass and a larger bone size. Keywords: bone mass; bone mineral content, BMC; bone mineral density, BMD; exercise; growth; nutrition; physical activity; skeletal structure (Published online: 1 October 2008) Citation: Food & Nutrition Research 2008. DOI: 10.3402/fnr.v52i0.1871

During pregnancy and lactation, changes occur in a variety of factors which have great potential to influence bone mineral density (BMD). Smoking habits, the level of alcohol consumption, the level of physical activity, body weight, soft tissue composition and hormone levels are all factors that change during the course of these conditions. Some of these factors are capable of increasing BMD, and some can reduce it. Due to these various changes, it is virtually impossible to predict the development in BMD that will occur during a pregnancy and lactation. However, longitudinal studies have suggested that both pregnancy and lactation are associated with a BMD loss of up to 5%, albeit that the BMD recovers after weaning. Cross-sectional studies have indicated that women with many children and a long total period of lactation have similar or higher BMD and similar or lower fracture risk than their peers who have not given birth. As the studies showing this trend have been observational and cross sectional case-control studies, the conclusions can only be regarded as being suggestive, and no causality can be proven.

is not availalbe.

Former male young athletes partially lost benefits in BMD (g/cm2) with cessation of exercise, but, despite this, had a higher BMD 4 years after cessation of career than a control group. A higher BMD might contribute to the lower incidence of fragility fractures found in former older athletesor =60 years of age compared with a control group.Physical activity increases peak bone mass and may prevent osteoporosis if a residual high BMD is retained into old age.BMD was measured by DXA in 97 male young athletes 21.0 +/- 4.5 years of age (SD) and 48 controls 22.4 +/- 6.3 years of age, with measurements repeated 5 years later, when 55 of the athletes had retired from sports. In a second, older cohort, fracture incidence was recorded in 400 former older athletes and 800 controlsor =60 years of age.At baseline, the young athletes had higher BMD than controls in total body (mean difference, 0.08 g/cm2), spine (mean difference, 0.10 g/cm2), femoral neck (mean difference, 0.13 g/cm2), and arms (mean difference, 0.05 g/cm2; all p0.001). During the follow-up period, the young athletes who retired lost more BMD than the still active athletes at the femoral neck (mean difference, 0.07 g/cm2; p = 0.001) and gained less BMD at the total body (mean difference, 0.03 g/cm2; p = 0.004). Nevertheless, BMD was still higher in the retired young athletes (mean difference, 0.06-0.08 g/cm2) than in the controls in the total body, femoral neck, and arms (all p0.05). In the older cohort, there were fewer former athletesor =60 of age than controls with fragility fractures (2.0% versus 4.2%; p0.05) and distal radius fractures (0.75% versus 2.5%; p0.05).Although exercise-induced BMD benefits are reduced after retirement from sports, former male older athletes have fewer fractures than matched controls.

Background: The purpose of this study was to evaluate the incidence and the long-term results of closed uncomplicated Mason type-II and III fractures in a defined population of adults. Methods: Seventy women and thirty men who were a mean of forty-seven years old when they sustained a fracture of the radial head or neck (a Mason type-II fracture in seventy-six patients and a Mason type-III fracture in twenty-four) were reexamined after a mean of nineteen years. Radiographic signs of degenerative changes of the elbow were recorded. The fracture had been treated with an elastic bandage or a collar and cuff sling with mobilization for forty-four individuals, with cast immobilization for thirty-four, with resection of the radial head in nineteen, with open reduction of the radial head in two, and with a collateral ligament repair in one. Secondary excision of the radial head was performed because of residual pain in nine patients, and a neurolysis of the ulnar nerve was performed in one patient. Results: Seventy-seven individuals had no symptoms in the injured elbow at the time of follow-up, twenty-one had occasional pain, and two had daily pain. The injured elbows had a slight flexion deficit compared with the uninjured elbows (mean and standard deviation, 138° ± 8° compared with 140° ± 7°) as well as a small extension deficit (mean and standard deviation, –4° ± 8° compared with –1° ± 6°) (p < 0.001 for both). The prevalence of degenerative changes was higher in the injured elbows than in the uninjured ones (76% compared with 16%, p < 0.001). Conclusions: The results following uncomplicated Mason type-II and III fractures are predominantly favorable. A secondary radial head resection is usually effective for patients with an unfavorable outcome (predominantly long-standing pain). Levels of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Study Design. The study is an observational cohort study. Objectives. To determine the incidence and the long-term outcome of thoracic or lumbar vertebral fractures in children. Summary of Background Data. The incidence of vertebral fractures in children is described as rare and the outcome as favorable. However, no studies evaluate the clinical and radiographic long-term outcome and if a fractured vertebra could be rebuilt during growth. Method. The incidence of vertebral fractures in children was evaluated through the radiographic archives. Twelve boys and 12 girls, aged 7-16 when sustaining the fracture, 21 one-column compression fractures and 3 burst fractures Denis type B, all without neurologic deficits, attended the follow-up. Primary treatment consisted of immediate mobilization without brace. Clinical and radiographic examination were performed 27-47 years after the injury. Results. The annual incidence of thoracic and lumbar vertebral body fractures in individuals below age 16 was 0.07%. Twenty-one individuals had, at follow-up. no subjective complaints, 3 had occasional back pain (Oswestry Scores, 8, 22, and 26), 23 were classified as Frankel E, and 1 as Frankel D. The radiographic ratio anterior height/posterior height of the fractured vertebral body increased from 0.75 after injury to 0.87 at follow-up (P

BackgroundAlthough the exact cause of medial tibial stress syndrome is unclear, changes in bone metabolism are likely to be involved.HypothesisLocalized low bone mineral density at the junction of the middle and distal thirds of the tibia in patients with medial tibial stress syndrome develops in conjunction with the symptoms; these changes are reversible and are not inherited.Study DesignProspective cohort study.MethodsBone mineral density in 14 adult male athletes with long-standing medial tibial stress syndrome was measured when they were symptomatic and after recovery (mean follow-up, 5.7 years). Repeat measurements were also made prospectively in 13 nonathlete control subjects and single measurements were made in 18 healthy athletes.ResultsBone mineral density was 9% ± 11% higher in the proximal tibia but 11% ± 12% lower in the tibial region corresponding to pain in patients when compared with nonathlete control subjects. It increased by 19% ± 11% in the region of pain after recovery from symptoms and, at follow-up, was no lower than in nonathlete control subjects.ConclusionAthletes with medial tibial stress syndrome and increased scintigraphic uptake regain normal tibial bone mineral density after recovery from symptoms. Initially localized low bone mineral density is not an inherited condition, but instead may develop in conjunction with the symptoms.

The relationship between duration of exercise and serum remodeling markers of bone turnover was evaluated by osteocalcin (OC), carboxy-terminal propeptide of type I collagen (PICP), total and bone-specific alkaline phosphatase (ALP) and carboxyterminal cross-linked telopeptide of type I collagen (ICTP) in 24 male premier league soccer players exercising 12 hours/week (range 8-18), 19 third league players exercising 8 hours/week (range 3-18) and 20 sixth league players exercising 6 hours/week (range 2-10). Twenty-seven volunteers served as controls. Forty-six former male soccer players (mean age 38 years, range 19-47), mean 15 years older than the current players, were compared with 41 matched controls. Data is presented as mean +/- SEM. Active male players had 18 +/- 4% higher OC, 37 +/- 9% higher bone ALP and 36 +/- 7% higher ICTP than controls (all P < 0.01). There were no differences in remodeling markers within the three groups of active players but each group had higher OC and ICTP than controls (both P < 0.05). Former players had no difference in bone remodeling markers compared to matched controls, but 39 +/- 4% lower OC and 69 +/- 8% lower ICTP than active players (both P < 0.001). Duration of activity was correlated with bone ALP and ICTP (both r = 0.3, P < 0.05) in individuals exercising 6 hours/week or less. No correlation was found in those exercising above this level. It seems as if the bone turnover, evaluated by serum bone remodeling markers, adapts to the current activity needed to maintain bone strength, and a duration of exercise above that level seems to confer no additional benefits.

Two different internal fixation techniques for closed displaced fractures of the olecranon were evaluated at a mean of 18 years after injury. Thirty-two of the patients received tension-band wiring, and 35 received figure-of-eight wiring. There were 41 women (mean age, 52 years) and 26 men (mean age, 32 years) included. The results revealed that 80% of the patients had no subjective complaints, 16% had occasional pain, and 4% had daily pain. Comparison of the injured and uninjured elbows demonstrated a 3 degrees reduction of flexion (P

Exercise during growth and adolescence increases bone mineral density (BMD) in weight-loaded skeletal regions. The development of BMD in unloaded or minimally loaded regions during activity is unclear. We measured BMD in one unloaded, one partly loaded and one highly loaded skeletal region in 67 active soccer players, mean age 22.7 years (range 17-35 years), 128 former soccer players, mean age 54.0 years (range 19-85 years) and 138 controls, mean age 50.6 years (range 19-80 years). The active soccer players played at three different levels: premier league, 3rd league or 6th league. Duration of exercise in these three grou s was 12, 8 and 6 h/week, respectively. BMD (g/cm ) was measured by dual-energy X-ray absorptiometry (DXA) in the upper part of the skull (the unloaded skeletal region), the arms (the partly loaded region) and the femoral neck (the maximal loaded region). Data are presented as mean +/- SD. Active soccer players had 10.3 +/- 10.4% lower BMD in the upper part of the skull (p < 0.001), 1.4 +/- 6.3% higher BMD in the arm (NS) and 12.7 +/- 9.8% higher BMD in the femoral neck (p

Exercise is associated with increased peak bone mineral density (BMD). To determine the relationship between the duration of exercise and BMD, we measured BMD of the axial and appendicular skeleton by dual-energy X-ray absorptiometry (DXA), and speed of sound (SOS), broadband attenuation (BUA), and stiffness index by quantitative ultrasound (QUS) of the calcaneus, in 67 active male national soccer players (mean age 23 years, range 17-35), which included 23 premier-league players exercising 12 h/week (range 8-18), 23 third-league players exercising 8 h/week (range 3-18), and 21 sixth-league players exercising 6 h/week (range 2-10). Results were compared with 24 sedentary age- and gender-matched controls and presented as mean +/- SEM. BMD was higher in all weight-bearing regions for the whole group relative to controls (BMD: total body 6.8 +/- 0.7%, leg 9.6 +/- 0.8%, lumbar spine 13.2 +/- 1.2%, femoral neck 12.7 +/- 1.2% [all p < 0.001]; calcaneus SOS 4.2 +/- 0.3%, BUA 8.7 +/- 1.5%, and stiffness index 24.2 +/- 2.0% [all p < 0.01]). No differences were found in head or arm BMD. There were no differences in BMD or QUS measurements when comparing soccer players exercising for different activity durations. Duration of activity correlated with BMD weight-loaded regions and with QUS, provided it was less

If exercise is to be recommended during growth, benefits in bone mineral density (BMD) must be maintained in old age and shown to prevent fractures. Our cross-sectional study of soccer players suggests that a high BMD is no longer recorded after retirement and fracture frequency is no less than predicted in old age.

Background: The prevalence of osteoporosis with related fragility fractures has increased during the last decades. As physical activity influences the skeleton in a beneficial way, exercise may hypothetically be used as a prophylactic tool against osteoporosis. Objective: This review evaluates if exercise-induced skeletal benefits achieved during growth remain in a long-term perspective. Design: Publications within the field were searched through Medline (PubMed) using the search words: exercise, physical activity, bone mass, bone mineral content (BMC), bone mineral density (BMD) and skeletal structure. We based our inferences on publications with the highest level of evidence, particularly randomised controlled trials (RCT). Results: Benefits in BMD achieved by exercise during growth seem to be eroded at retirement, but benefits in skeletal structure may possibly be retained in a longer perspective. Recreational exercise seems to at least partially maintain exercise-induced skeletal benefits achieved during growth. Conclusions: Exercise during growth may be followed by long-term beneficial skeletal effects, which could possibly reduce the incidence of fractures. Exercise during adulthood seems to partly preserve these benefits and reduce the age-related bone loss. Keywords: bone mass; bone mineral content, BMC; bone mineral density, BMD; exercise; physical activity; skeletal architecture (Published online: 1 October 2008) Citation: Food & Nutrition Research 2008. DOI: 10.3402/fnr.v52i0.1872

Background Intense physical activity (PA) improves muscle strength in children, but it remains uncertain whether moderately intense PA in a population-based cohort of children confers these benefits. Methods We included children aged 6–9 years in four schools where the intervention school increased the school curriculum of PA from 60 minutes/week to 40 minutes/school day while the control schools continued with 60 minutes/week for three years. We measured muscle strength, as isokinetic Peak Torque (PT) (Nm) of the knee flexors in the right leg at speeds of 60°/second and 180°/second, at baseline and at follow-up, in 47 girls and 76 boys in the intervention group and 46 girls and 54 boys in the control group and then calculated annual changes in muscle strength. Data are provided as means with 95% confidence intervals. Results Girls in the intervention group had 1.0 Nm (0.13, 1.9) and boys 1.9 Nm (0.9, 2.9) greater annual gain in knee flexor PT at 60°/ second, than girls and boys in the control group. Boys in the intervention group also had 1.5 Nm (0.5, 2.5) greater annual gain in knee flexors PT at 180°/ second than boys in the control group. Conclusion A 3-year moderately intense PA intervention program within the school curriculum enhances muscle strength in both girls and boys. Electronic supplementary material The online version of this article (doi:10.1186/1471-2474-15-353) contains supplementary material, which is available to authorized users.