A WEIGHTED VEST TO PREVENT LEG WEAKNESS AND OSTEOPOROSIS

该项目将包括为期两年的干预发展研究 随后进行为期3年的干预研究(IS)。整体而言 该项目的目标是测试穿着加重背心是否可以 预防肌肉无力和骨质疏松症。首先，入侵检测系统将是 以进一步细化防弹背心剂量并评估 可以测量背心使用时骨负荷的生物力学近似值。 第二，将进行随机对照试验，以检验 背心对肌肉力量和骨密度的影响。 尼龙背心的重量最大可达12公斤，这是规定的 以体重的百分比(%BW)表示。受试者在例行公事中穿着背心 日常活动(如家务、散步)，每天2小时，每天4天 星期。不需要额外的具体体力活动处方。 入侵检测系统将包括27周的3人武装(对照，3%体重，5%体重)的岗位前 60名受试者比较这几种剂量对膝关节影响的研究 伸肌强度、副作用和粘连性。先前的马甲研究 建议5%的体重是该人群所能容忍的最大值；因此， IS选择最大剂量和1/2最大剂量。该药的剂量为 RCT将根据每个人对：膝关节伸肌的影响而决定 力量、安全和坚守。 入侵检测系统将评估建议的髋关节生物力学措施 载荷、髋关节反作用力和髋力矩随 背心的使用。不同剂量背心对骨转换的影响：1 指标；2)步态和平衡；3)自我报告的功能状态和 观察到的体能表现将被评估。坚持使用马甲 干预终止后3个月和6个月也将 检查过了。 IS将由为期24个月的单盲、双臂随机分组组成 66例受试者的对照试验。它将检验一剂疫苗的效果。 背心(由入侵检测系统确定)与注意力控制的比较 分组如下：1)总髋部骨密度；2)骨量和时间进程 等速膝关节伸肌力量的变化；3)长期安全性 属于并坚持使用背心。如果入侵检测系统在#年取得成功 量化髋关节负荷的假定生物力学指标，a 区域合作研究的第四个主要目标将是评估 生物力学方法预测骨密度的变化，探讨 背心完成骨骼取向的机制。 RCT的次要目标包括衡量防护衣的效果 用途：脊柱骨密度；全身钙；身体成分；骨转换 标记；步态和平衡；功能状态；和体能表现。

This project will consist of a 2-year intervention development study (IDS) followed by a 3-year intervention study (IS). The overall objective of the project is to test whether wearing a weighted vest can prevent muscular weakness and osteoporosis. First, an IDS will be conducted to further refine the vest dose and to assess whether biomechanical approximations of bone loading by vest use can be measured. Second, a randomized controlled trial will be conducted to test the effect of the vest on muscular strength and bone mineral density. The nylon vest can be weighted to a maximum of 12 kg and is prescribed as a percent of body weight (%BW). Subjects wear the vest during routine daily activities (eg, chores, walks) for 2 hours per day, 4 days per week. No additional specific physical activity prescription is required. The IDS will consist of a 27-week, 3-armed (control, 3%BW, 5%BW) pre-post study in 60 subjects to compare the effects of these doses on knee extensor strength, side-effects, and adherence. Prior vest studies suggest that 5%BW is the maximum tolerated in this population; thus, maximum and 1/2 maximum dose are selected for the IS. The dose for the RCT will be decided based on the effect of each on: knee extensor strength; safety; and adherence. The IDS will evaluate whether proposed biomechanical measures of hip loading, hip joint reaction forces and hip moments-of-force, change with vest use. The effects of each vest dose on: 1) bone turnover indicators; 2) gait and balance; 3) self-reported functional status and observed physical performance will be assessed. Adherence to vest use 3 and 6 months after the termination of the intervention will also be examined. The IS will consist of a 24-month, single blinded, two armed randomized controlled trial in 66 subjects. It will examine the effects of one dose of the vest (determined by the IDS) compared to an attention control group on the following: 1) total hip BMD; 2) amount and time course of change in isokinetic knee extensor strength; and 3) long-term safety of and adherence to vest use. If the IDS has been successful in quantifying the postulated biomechanical measures of hip loading, a fourth primary objective of the RCT will be to assess the ability of the biomechanical measures to predict changes in BMD, to explore the mechanism by which the vest accomplishes bone tropism. The secondary RCT objectives include measurement of the effect of vest use on: spinal BMD; total body calcium; body composition; bone turnover markers; gait and balance; functional status; and physical performance.