Outcomes after selective nerve root blockade for lumbar radicular pain from lumbar disc hernia or lumbar spinal stenosis assessed by the PROMIS-29 - a prospective observational cohort study.

PURPOSE: Selective nerve root blocks (SNRB) are used both as a therapeutic and diagnostic tool for lumbar radicular pain. Most studies evaluate the effect of SNRB simply by its relation to pain reduction. It is well known that pain is associated with other factors such as depression, anxiety, inactivity and sleeping disorders, but these patient-related outcomes are seldom evaluated. This study evaluated the influence of SNRB on pain-related outcomes including depression, anxiety, fatigue, pain interference, activity and sleep. METHODS: One hundred three patients with lumbar radicular pain were treated with a SNRB. Patient-reported outcome measures (PROMs) were assessed with the PROMIS-29 for 12 weeks (84 days) following the SNRB. Patients were stratified based on their pain reduction at the 14-day follow up as responders (≥ 30% pain reduction) and non-responders (< 30% pain reduction). Post-treatment duration was estimated with the Kaplan-Meier analysis with return to baseline as an event. A paired t-test was used to compare pre- and post-treatment responses at specific time intervals. RESULTS: Forty-four percent (n = 45) of the patients were responders and showed significant improvement in all parameters throughout the 84-days follow-up, the exception was sleep that lost significance at day 70. The mean post-treatment duration among responders was 59 (52-67) days. Non-responders showed significant improvements in pain interference and pain intensity until day 35 and in ability for social participation until 21-day. CONCLUSION: SNRB can improve pain intensity, pain interference, physical function, fatigue, anxiety, depression, sleep disturbance and the ability to participate in social roles.

[Atlantoaxial rotatory subluxation - a cause of torticollis in children]. / Atlantoaxial subluxation kan vara en orsak till tortikollis hos barn.

Atlantoaxial rotatory subluxation is an important differential diagnosis in young children with torticollis. The condition rarely results in neurological deficits. Radiological examinations such as computer tomography (CT) and magnetic resonance imaging (MRI) are useful to determine the diagnosis. It is important for doctors in all areas of healthcare to be aware of the condition, as persistent problems or surgery can be avoided by early detection and treatment.

Same lung deposited dose in dog dosing a fine and coarse aerosol indicates no difference in intranasal filtration.

A novel inhalation exposure system was developed with the aim to increase the efficiency of pharmacokinetic (PK) evaluations of inhaled drugs in a large species such as the dog. It enables collecting PK data for multiple drug candidates in a single experiment by simultaneous administration of the drugs to the same animal. This facilitates a direct PK comparison of the same lung dose of different drugs using the same blood samples, which can be considered to be a refinement measure from an animal research perspective. The system design was inspired by a clinical precision dosing dosimeter systems, which enhance dosing precision by synchronizing the aerosol delivery from the jet nebulizer with the inhalation to maximize the inhaled fraction of the nebulized dose. The performance of the novel system was validated in an in-vivo study, which included a comparison of the same nebulized dose delivered as a fine and a coarse aerosol. The drugs selected for this study were developed for local treatment of the lung via inhalation and were known to have low oral bioavailability due to being extremely poorly soluble and therefore expected to also have low nasal bioavailability. This would result in systemic exposure derived primarily from pulmonary absorption, which facilitated the PK assessment applied to determine the lung deposited dose. The jet nebulizer selected to generate a fine aerosol was designed for alveolar lung deposition and approved by U.S. Food and Drug Administration for lung ventilation imaging, and the nebulizer selected to generate a coarse aerosol was a standard nebulizer. The drugs were wet milled to a particle size considerably smaller than the nebulized droplets and the dispersed drug particles were therefore homogenously distributed in the droplet size distribution. Higher initial plasma concentrations were observed for the fine aerosol. This was expected, as the smaller droplets should deposit more efficiently in the peripheral regions of the lung, which consequently should lead to a faster absorption compared with the coarse aerosol from the standard nebulizer that should deposit more centrally. The fact that this could be observed supports that the novel system is an excellent tool in PK evaluations. Our study indicated that there was no difference in the systemic exposure between the fine and the coarse aerosol for the same nebulized dose, and thus the lung deposition was also the same. The considerable difference in the nebulized size distribution within the range relevant for available inhalation devices resulted in a negligible difference in intranasal filtration. The fraction of the nebulized dose that deposited in the lung was observed to be high in this study (mean of 21-30% and about 50% for one dog with a distinguished slow and deep breathing), which supports that the intranasal filtration was low. That a high fraction of the nebulized dose deposited in the lung indicates that an enhanced dosing precision was obtained with the novel system. The similar achieved lung doses of all three drugs, shows that the simultaneous administration of multiple drugs worked well. That the intranasal filtration was low is an important finding considering that devices for oropharyngeal delivery in dogs are applied in order to eliminate intranasal filtration. Oropharyngeal dosing is more invasive compared with oronasal dosing and avoiding utilizing that method can be considered a refinement measure from an animal research perspective.

A Norm-Creative Method for Co-constructing Personas With Children With Disabilities: Multiphase Design Study.

BACKGROUND: An increase in the demand for child participation in health care requires tools that enable and empower children to be involved in the co-production of their own care. The development of such tools should involve children, but participatory design and research with children have challenges, in particular, when involving children with disabilities where a low level of participation is the norm. Norm-creative and participatory approaches may bring more effective design solutions for this group. "Personas" is a methodology for increasing user perspectives in design and offers representation when users are absent. However, research on participatory persona generation in this context is limited. OBJECTIVE: The objective of this study was to investigate how norm-creative and participatory design approaches can be integrated in a persona generation method to suit children with disabilities in the design of games for health that target this group. METHODS: The method development involved interview transcripts and image-based workshops. Sixteen children with various disabilities participated in persona generation through co-creation of characters and scenarios. The results from the workshops were validated together with 8 children without disabilities, 1 young adult with a disability, and 1 rehabilitation professional. A qualitative thematic design analysis was iterated throughout the process. RESULTS: The results consisted of an image-based and iterative co-construction method. It was accompanied by examples of personas that were generated and validated within a games for health case. The method showed effectiveness in enabling flexible co-construction and communication. The data resonated with social model perspectives, and the development is discussed in terms of participation levels, salutogenic descriptions of barriers, and norm-creative tradeoffs. CONCLUSIONS: The resulting method may influence future design projects toward more inclusiveness and enable increased representation for children with disabilities in research and design. Using this method to its full potential requires a norm-critical awareness as well as extensive facilitation. Suggestions for further research include the application of the method to design processes in similar contexts or user groups.

Daily School Physical Activity Improves Academic Performance.

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 6-8 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 2007-2012. 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 2003-2006, 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.

Daily School Physical Activity from Before to After Puberty Improves Bone Mass and a Musculoskeletal Composite Risk Score for Fracture.

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 < 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.

[Daily school physical activity increases bone mass and gradually reduce the fracture risk]. / Daglig skolidrott ger ökad benmassa och successivt minskad frakturrisk - Resultat från Bunkefloprojektet.

In the Bunkeflo project, one elementary school increased duration of school physical activity (PA) to 200 minutes/week while 3 control schools continued with 60 minutes/week throughout the nine elementary school years. We then registered fractures in 3534 children, and evaluated the duration of PA, bone mass and muscle strength in a subsample (n=140) during the intervention and 3 years after. The PA intervention was associated with higher duration of PA both during and 3 years after the intervention. With each year of intervention, the fracture incidence rate ratio (IRR) declined in the intervention children so that it was 0.48 (95% CI 0.25, 0.91) the eighth year of intervention. These findings were accompanied by beneficial gain in musculoskeletal traits in both intervention girls and boys (p<0.05). Nine years of daily school-based PA is associated with a progressive reduction in fracture risk, accompanied by beneficial musculoskeletal gains and a more physically active lifestyle.

[Daily physical activity during the nine compulsory school years improves academic school results in boys but not girls - a prospective controlled intervention study]. / Daglig fysisk aktivitet på schemat: bättre skolresultat hos pojkarna - Men för flickorna var det ingen skillnad ­ Bunkefloprojektet följde grundskoleelever under nio år.

One aim of the Bunkeflo project is to evaluate if daily school physical activity (PA) is associated with higher final school grades and improved eligibility for upper secondary school. One elementary school extended PA throughout elementary school to 200 minutes/week while control schools continued with in mean 60 minutes/week. We then registered final school grades and eligibility for upper secondary school in children who began first grade in the intervention school during the years before the intervention (1994-1997) and in the children who started 1998-2003 (that is, who had daily PA during the 9 compulsory school years). We also registered final school grades and eligibility for upper secondary school in all Swedish children who started school 1998-2003. We found that boys in the intervention group had higher eligibility rates and higher grade scores than boys who finished the same school before the intervention was implemented as well as higher in all Swedish boys. These differences in were not seen in girls. Daily school PA through elementary school is associated with higher final grade scores and higher eligibility rates for upper secondary school in boys.

Long-term effects of daily physical education throughout compulsory school on duration of physical activity in young adulthood: an 11-year prospective controlled study.

OBJECTIVES: We 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. METHODS: This 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. RESULTS: At 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). CONCLUSIONS: Intervention 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.

A comparative study found that a seven-year school-based exercise programme increased physical activity levels in both sexes.

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.

Natural Hazard Susceptibility Assessment for Road Planning Using Spatial Multi-Criteria Analysis.

Inadequate infrastructural networks can be detrimental to society if transport between locations becomes hindered or delayed, especially due to natural hazards which are difficult to control. Thus determining natural hazard susceptible areas and incorporating them in the initial planning process, may reduce infrastructural damages in the long run. The objective of this study was to evaluate the usefulness of expert judgments for assessing natural hazard susceptibility through a spatial multi-criteria analysis approach using hydrological, geological, and land use factors. To utilize spatial multi-criteria analysis for decision support, an analytic hierarchy process was adopted where expert judgments were evaluated individually and in an aggregated manner. The estimates of susceptible areas were then compared with the methods weighted linear combination using equal weights and factor interaction method. Results showed that inundation received the highest susceptibility. Using expert judgment showed to perform almost the same as equal weighting where the difference in susceptibility between the two for inundation was around 4%. The results also showed that downscaling could negatively affect the susceptibility assessment and be highly misleading. Susceptibility assessment through spatial multi-criteria analysis is useful for decision support in early road planning despite its limitation to the selection and use of decision rules and criteria. A natural hazard spatial multi-criteria analysis could be used to indicate areas where more investigations need to be undertaken from a natural hazard point of view, and to identify areas thought to have higher susceptibility along existing roads where mitigation measures could be targeted after in-situ investigations.

How does a physical activity programme in elementary school affect fracture risk? A prospective controlled intervention study in Malmo, Sweden.

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.

A Physical Activity Intervention Program in School is Also Accompanied by Higher Leisure-Time Physical Activity: A Prospective Controlled 3-Year Study in 194 Prepubertal Children.

BACKGROUND: The activity-stat theory infers that total physical activity (PA) in children is constant, independent of environmental interventions. METHODS: We conducted a 3-year prospective population-based controlled PA intervention study including, at baseline, 7- to 9-year-old children (66 boys, 40 girls in the intervention and 50 boys, 38 girls in the control group). PA was increased in the intervention group from 60 to 200 minutes/week, while the controls maintained 60 minutes/week. We registered weekly duration of total PA and leisure-time PA and daily duration of sedentary activities, through questionnaires at baseline and 2 and 3 years after baseline. RESULTS: Between intervention and control groups PA was similar before intervention start. After intervention start, total PA in both genders was increased during the entire period (P-values adjusted for age and Tanner stage at follow-up between 0.001 and 0.002). Duration of sedentary activities was unchanged with no group differences. Children in the intervention group changed their behavior so that they also achieved more leisure-time PA. CONCLUSIONS: A 3-year school-based PA intervention program in prepubertal children increases the duration of total PA without increasing the duration of sedentary activities, and the program seems to initiate more PA during leisure-time. Our results refute the activity-stat theory.

Effects of an 8-year childhood physical activity intervention on musculoskeletal gains and fracture risk.

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 200min per school week and followed 65 girls and 93 boys from a mean age of 7years until a mean age of 15years. Thirty-nine girls and 37 boys in three other schools continued with 60min 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.

A seven-year physical activity intervention for children increased gains in bone mass and muscle strength.

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/cm(2) (0.01-0.08) more total spine aBMD (p < 0.05) and 6.2Nm (1.6, 10.7) more knee flexion strength (p < 0.01) than control group girls and had a 0.1 mm (0.0, 0.3) higher tibial cortical thickness at follow-up (p < 0.05). Boys in the intervention group gained 7.3Nm (0.4, 14.2) more knee extension strength (p < 0.05) and 7.4Nm (2.3, 12.4) more knee flexion strength (p < 0.01) than the control group boys, but their aBMD was no higher than the control group. CONCLUSION: A seven-year, population-based moderately intense exercise intervention enhanced gains in spine bone mass in girls and knee muscle strength in both genders.

Osteoarthritis of the Distal Interphalangeal and First Carpometacarpal Joints is Associated with High Bone Mass in Women and Small Bone Size and Low Lean Mass in Men.

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.

A Pediatric Bone Mass Scan has Poor Ability to Predict Peak Bone Mass: An 11-Year Prospective Study in 121 Children.

This 11-year prospective longitudinal study examined how a pre-pubertal pediatric bone mass scan predicts peak bone mass. We measured bone mineral content (BMC; g), bone mineral density (BMD; g/cm(2)), and bone area (cm(2)) in femoral neck, total body and lumbar spine by dual-energy X-ray absorptiometry 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. The correlation coefficients (r) between pre-pubertal and young adulthood measurements for femoral neck BMC, BMD, and bone area varied between 0.37 and 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 were 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 % confidence interval (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. 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.

Patients with knee osteoarthritis have a phenotype with higher bone mass, higher fat mass, and lower lean body mass.

BACKGROUND: 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. QUESTIONS/PURPOSES: 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? METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. CLINICAL RELEVANCE: 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.

Patients with Osteoarthritis in all Three Knee Compartments and Patients with Medial Knee Osteoarthritis Have a Phenotype with High Bone Mass and High Fat Mass but Proportionally Low Lean Mass.

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/cm(2)), fat and lean mass (%) by dual energy X-ray absorptiometry and also registered height and weight to calculate BMI (kg/m(2)). 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.

A 3-year school-based exercise intervention improves muscle strength - a prospective controlled population-based study in 223 children.

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.