CHILD MOBILITY: ROLE OF STRENGTH, BODY FAT & ENERGY COST

力量是决定行动状态的最重要因素 在有运动障碍的儿童中。肥胖，一个常见的问题 在残疾儿童中，是第二个负面的重要因素 影响残疾儿童的行动能力。这项研究 重点关注力量和体脂作为能源成本的决定因素 变数儿童的步行和轮椅运动能力 脊髓脊膜膨出(MM)所致的活动障碍程度， 脊髓损伤(SCI)、脑性瘫痪(CP)和杜兴 肌营养不良(DMD)。具体地说， 该提案将解决两个假设：1)身体脂肪过多 增加行走和轮椅移动的能源成本 除了与瘦身纸巾相关的成本增加之外 缺陷和弱点，以及2)更高的移动能源成本 与每日总能源消耗的减少有关 (TEE)和体力活动；减少体力活动将 与肥胖症的增加有关。研究人群 由375名6至20岁的男女儿童组成：90 MM，45 脊髓损伤组、120个CP组、30个DMD组和90个对照组。测量包括：1) 人体测量学，2)全身和局部身体成分 双能X射线吸收法(DXA)，3)定量等轴测 肘部和膝部的等速力量，4)休息 用间接量热法测定代谢率(RMR)，5)能源成本 步行和/或轮椅活动(毫升O2/公斤米和 千卡/千克米)通过便携式遥测代谢，测量 6)TEE和体力活动指数(TEE/RMR比率) 连续三天监测心率(HR)。能量 移动成本将在基线时获取，并在添加 通过骨盆腰带增加的体重相当于身体百分比增加10% 脂肪和身体脂肪百分比增加20%。我们将确定 薄弱环节的相对重要性和瘦肉率的降低 组织对总体质量的产生增加了能源成本 运动减少，体力活动减少(从 TEE：RMR比率)和残疾人肥胖增加的风险 孩子们。两项能源节约的客观措施 运动和体力活动在功能上是相关的 结果。建立一种双方受损的关系 体力和肥胖度增加导致能源成本增加，以及 因此，减少体力活动，将为多样化提供基础 改善功能活动的干预措施。成果研究 评估旨在改善能源状况的干预措施 运动的效率还需要考虑身体 如果确实存在重大变化，则组成会随时间发生变化 移动过程中增加的能源成本与 肥胖症增加。

Strength is the most important determinant of mobility status among children with motor impairments. Obesity, a common problem among disabled children, is a second important factor negatively influencing mobility status in disabled children. this study focuses on strength and body fat as determinants of energy cost of ambulation and wheelchair locomotion in children with variable degrees of mobility impairment due to myelomeningocele (MM), spinal cord injury (SCI), cerebral palsy (CP), and Duchenne Muscular dystrophy (DMD). Specifically, the primary aims of the proposal will address two hypotheses: 1) excess body fat increases the energy cost of ambulation and wheelchair locomotion over and beyond the increased costs associated with lean tissue deficits and weakness, and 2) higher energy cost of locomotion is associated with reductions in daily total energy expenditure (TEE) and physical activity; reduced physical activity will be associated with increased adiposity. The study population consists of 375 male and female children ages 6 to 20: 90 MM, 45 SCI, 120 CP, 30 DMD, and 90 controls. Measurements include: 1) anthropometrics, 2) whole body and regional body composition by dual-energy x-ray absorptiometry (DXA), 3) quantitative isometric and isokinetic strength at the elbow and knee, 4) resting metabolic rate (RMR) by indirect calorimetry, 5) energy cost of ambulation and/or wheelchair locomotion (ml O2/Kg meter and Kcal/Kg meter) via a portable telemetric metabolic, measurement system, and 6) TEE and physical activity index (TEE/RMR ratio) by continuous three day heart rate (HR) monitoring. The energy cost of locomotion will be accessed at baseline and with added weight via a pelvic belt equivalent to a 10% increase in % body fat and a 20% increase in % body fat. We will determine the relative importance of weakness and decreased ratio of lean tissue to total body mass in producing increased energy cost of locomotion, reduced physical activity (as evidenced by the TEE:RMR ratio) and a risk of increased adiposity for disabled children. Objective measures of both energy economy of locomotion and physical activity are functionally relevant outcomes. Establishment of a relationship of both impaired strength and increased adiposity to increased energy cost, and hence, reduced physical activity, will provide a basis for varied interventions to improve functional mobility. Outcome studies assessing interventions directed at improving the energy efficiency of locomotion will need to also consider body composition changes over time if there are indeed significant incremental energy costs during locomotion associated with increased adiposity.