Quantifying the relationship between mechanical loading and the skeletal response in pre- and early-pubertal girls

PURPOSEBefore exercise prescription for bone health can be recommended, the relationship between mechanical loading characteristics and the skeletal response need to be quantified. We asked i) does moderate impact exercise result in a greater gain in BMC than low impact exercise, ii) what are the loading characteristics associated with a moderate and low impact exercise program and does this differ from non-structured play?, and iii) does loading history affect the osteogenic response to a moderate or low impact program? METHODSSixty-eight pre- and early-pubertal girls (aged 8.9 +/- 0.2 yrs) were randomized to take part in a moderate or low impact exercise program 3 times/wk for 8.5 mnths. The number and type of loads associated with the exercise classes and non-structured play (recess) were assessed from video footage. The magnitude of load was assessed using a pedar in-sole mobile system. Hours of moderate and high impact organized sport were assessed from a physical activity questionnaire. RESULTSThe moderate and low impact exercise programs consisted of -400 impacts per class, but the jumping, hopping and dynamic activities performed during the moderate impact program produced forces ranging from 2 to 4 times body weight (BW) compared to -1 BW for the low impact program. Moderate impact exercise resulted in a 2.7% greater gain in BMC at the tibia compared to the low impact exercise. The moderate impact exercise program consisted of fewer low impacts (1-2 BW) and a higher number of moderate impacts (2-4BW) compared to those typically performed during non-structured play. There were greater gains in BMC in subjects participating in the moderate versus the low impact exercise programs who participated in 2 to 3 hours of moderate impact sports outside school (2.5% to 4.5%, p CONCLUSIONApproximately 400 impacts ranging 2-4 BW, 3 times/wk was enough stimuli to result in an osteogenic response in normally active girls; even in those actively involved in moderate impact sports outside school.<br /

Predicting growth and curve progression in the individual patient with adolescent idiopathic scoliosis: design of a prospective longitudinal cohort study

<p>Abstract</p> <p>Background</p> <p>Scoliosis is present in 3-5% of the children in the adolescent age group, with a higher incidence in females. Treatment of adolescent idiopathic scoliosis is mainly dependent on the progression of the scoliotic curve. There is a close relationship between curve progression and rapid (spinal) growth of the patient during puberty. However, until present time no conclusive method was found for predicting the timing and magnitude of the pubertal growth spurt in total body height, or the curve progression of the idiopathic scoliosis.</p> <p>The goal of this study is to determine the predictive value of several maturity indicators that reflect growth or remaining growth potential, in order to predict timing of the peak growth velocity of total body height in the individual patient with adolescent idiopathic scoliosis. Furthermore, different parameters are evaluated for their correlation with curve progression in the individual scoliosis patient.</p> <p>Methods/design</p> <p>This prospective, longitudinal cohort study will be incorporated in the usual care of patients with adolescent idiopathic scoliosis. All new patients between 8 and 17 years with adolescent idiopathic scoliosis (Cobb angle >10 degrees) visiting the outpatient clinic of the University Medical Center Groningen are included in this study. Follow up will take place every 6 months. The present study will use a new ultra-low dose X-ray system which can make total body X-rays. Several maturity indicators are evaluated like different body length dimensions, secondary sexual characteristics, skeletal age in hand and wrist, skeletal age in the elbow, the Risser sign, the status of the triradiate cartilage, and EMG ratios of the paraspinal muscle activity.</p> <p>Correlations of all dimensions will be calculated in relationship to the timing of the pubertal growth spurt, and to the progression of the scoliotic curve. An algorithm will be made for the optimal treatment strategy in the individual patient with adolescent idiopathic scoliosis.</p> <p>Discussion</p> <p>This study will determine the value of many maturity indicators and will be useful as well for other clinicians treating children with disorders of growth. Since not all clinicians have access to the presented new 3D X-ray system or have the time to make EMG's, for example, all indicators will be correlated to the timing of the peak growth velocity of total body height and curve progression in idiopathic scoliosis. Therefore each clinician can chose which indicators can be used best in their practice.</p> <p>Trial registration number</p> <p>NTR2048</p

Non-pharmacological management of osteoporosis: a consensus of the Belgian Bone Club

This consensus article reviews the various aspects of the non-pharmacological management of osteoporosis, including the effects of nutriments, physical exercise, lifestyle, fall prevention, and hip protectors. Vertebroplasty is also briefly reviewed. Non-pharmacological management of osteoporosis is a broad concept. It must be viewed as an essential part of the prevention of fractures from childhood through adulthood and the old age. The topic also includes surgical procedures for the treatment of peripheral and vertebral fractures and the post-fracture rehabilitation. The present document is the result of a consensus, based on a systematic review and a critical appraisal of the literature. Diets deficient in calcium, proteins or vitamin D impair skeletal integrity. The effect of other nutriments is less clear, although an excessive consumption of sodium, caffeine, or fibres exerts negative effects on calcium balance. The deleterious effects of tobacco, excessive alcohol consumption and a low BMI are well accepted. Physical activity is of primary importance to reach optimal peak bone mass but, if numerous studies have shown the beneficial effects of various types of exercise on bone mass, fracture data as an endpoint are scanty. Fall prevention strategies are especially efficient in the community setting, but less evidence is available about their effectiveness in preventing fall-related injuries and fractures. The efficacy of hip protectors remains controversial. This is also true for vertebroplasty and kyphoplasty. Several randomized controlled studies had reported a short-term advantage of vertebroplasty over medical treatment for pain relief, but these findings have been questioned by recent sham-controlled randomized clinical studies

The influence of muscular action on bone strength via exercise

Mechanical stimuli influence bone strength, with internal muscular forces thought to be the greatest stressors of bone. Consequently, the effects of exercise in improving and maintaining bone strength have been explored in a number of interventional studies. These studies demonstrate a positive effect of high-impact activities (i.e. where large muscle forces are produced) on bone strength, with benefits being most pronounced in interventions in early pubertal children. However, current studies have not investigated the forces acting on bones and subsequent deformation, preventing the development of optimised and targeted exercise interventions. Similarly, the effects of number and frequency of exercise repetitions and training sessions on bone accrual are unexplored. There are conflicting results as to gender effects on bone response to exercise, and the effects of age and starting age on the osteogenic effects of exercise are not well known. It also appears that exercise interventions are most effective in physically inactive people or counteracting conditions of disuse such as bed rest. Bone strength is only one component of fracture risk, and it may be that exercise resulting in improvements in, e.g., muscle force/power and/or balance is more effective than those whose effects are solely osteogenic. In summary, exercise is likely to be an effective tool in maintaining bone strength but current interventions are far from optimal. © Springer Science+Business Media 2013

Weight loss in elderly women in low-level care and its association with transfer to high-level care and mortality

Julie L Woods1, Sandra Iuliano-Burns2, Karen Z Walker11Department of Nutrition and Dietetics, Monash University, Clayton; 2Endocrine Centre of Excellence, Department of Medicine, Austin Health, University of Melbourne, West Heidelberg, Victoria, AustraliaBackground: The purpose of this study was to determine whether unintentional weight loss in older women predicts an imminent transition out of low-level care (either to higher-level care or by mortality).Methods: Fifty-three Australian women, ambulatory while living in low-level care and requiring minimal assistance, were studied. At baseline, when the women were aged (mean &plusmn; standard deviation) 86.2 &plusmn; 5.3 years, body composition was assessed by dual energy X-ray absorptiometry, dietary intake was determined by a three-day weighed food record, a venous blood sample was taken, and both muscle strength and physical functioning were measured. The women were then followed up for 143 weeks to record the composite outcome of transfer to high-level care or mortality.Results: During follow-up, unintended loss of body weight occurred in 60% of the women, with a mean weight loss of -4.6 &plusmn; 3.6 kg. Seven women (13.2%) died, and seven needed transfer to high-level care. At baseline, those who subsequently lost weight had a higher body mass index (P&nbsp;&lt; 0.01) because they were shorter (P&nbsp;&lt; 0.05) but not heavier than the other women. Analysis of their dietary pattern revealed a lower dietary energy (P&nbsp;&lt; 0.05) and protein intake (P&nbsp;&lt; 0.01). The women who lost weight also had lower hip abductor strength (P&nbsp;&lt; 0.01), took longer to stand and walk (P&nbsp;&lt; 0.05), and showed a slower walking speed (P&nbsp;&lt; 0.01). Their plasma C-reactive protein was higher (P&nbsp;&lt; 0.05) and their serum albumin was lower (P&nbsp;&lt; 0.01) than women who did not lose weight. Nonintentional weight loss was a significant predictor of death or transfer to high care (hazards ratio 0.095, P = 0.02).Conclusion: Weight loss in older women predicts adverse outcomes, so should be closely monitored.Keywords: aged care, weight loss, mortality, high car

Timing and magnitude of peak height velocity and peak tissue velocities for early, average, and late maturing boys and girls

Height, weight, and tissue accrual were determined in 60 male and 53 female adolescents measured annually over six years using standard anthropometry and dual-energy X-ray absorptiometry (DXA). Annual velocities were derived, and the ages and magnitudes of peak height and peak tissue velocities were determined using a cubic spline fit to individual data. Individuals were rank ordered on the basis of sex and age at peak height velocity (PHV) and then divided into quartiles: early (lowest quartile), average (middle two quartiles), and late (highest quartile) maturers. Sex- and maturity-related comparisons in ages and magnitudes of peak height and peak tissue velocities were made. Males reached peak velocities significantly later than females for all tissues and had significantly greater magnitudes at peak. The age at PHV was negatively correlated with the magnitude of PHV in both sexes. At a similar maturity point (age at PHV) there were no differences in weight or fat mass among maturity groups in both sexes. Late maturing males, however, accrued more bone mineral and lean mass and were taller at the age of PHV compared to early maturers. Thus, maturational status (early, average, or late maturity) as indicated by age at PHV is inversely related to the magnitude and late maturers for weight and fat mass in boys and girls. Am. J. Hum. Biol. 13:1-8, 2001. (C) 2001 Wiley-Liss, Inc

Stepping towards prevention of bone loss after stroke : a systematic review of the skeletal effects of physical activity after stroke

2011-2012 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptSelf-fundedPublishe