Musculoskeletal Biomechanics of Gradient Walking in Obese Adults

描述（由申请人提供）：运动结合饮食干预仍然是对抗肥胖流行的最佳方法。快走是一种推荐和流行的运动形式，但负重运动可能是生物力学负荷的来源，增加肌肉骨骼损伤的风险，并将肥胖和大关节（如膝关节）骨关节炎（OA）联系起来。因此，从生物力学角度来看，将快走作为治疗肥胖的运动可能是不合理的。然而，对于肥胖是如何影响步行的生物力学负荷，我们所知甚少。现有的步行生物力学数据库并不适用于60%以上超重或肥胖的美国成年人，也不适用于上坡或下坡步行。本研究的长期目标是为肥胖成人提供步行运动处方，以最大限度地减少下肢生物力学负荷，同时优化热量消耗和心血管刺激。具体目标1：确定肥胖如何影响步行的生物力学。我们假设肥胖增加了下肢关节负荷，但适度倾斜结合步行速度的降低减少了这些负荷，而步行适度下降增加了下肢关节负荷。为了验证这些假设，肌肉骨骼生物力学将通过水平速度，三次倾斜和一次适度下降来测量，使用可倾斜的双带测力跑步机。研究对象包括肥胖和体重控制正常的男女受试者。具体目标2：为肥胖成人制定更合理的步行运动处方指南。我们假设，对于肥胖的成年人，缓慢地走上中等坡度可以最大限度地减少膝关节负荷，同时优化热量消耗和心血管刺激。为了验证这一假设，我们将结合特异性目标1的生物力学结果，测量肥胖和正常体重成人的步行代谢成本和最大耗氧量。我们将能够确定速度和坡度组合，以达到推荐的可持续适度有氧强度（最大摄氧量的55-70%，VO2max）和最低的生物力学负荷。这项研究的好处将是为体重管理和心血管健康提供更明智、更安全、更有效的步行运动处方。我们确定的步行方案在短期内（降低急性损伤率）和长期（降低OA风险）应该更安全。

DESCRIPTION (provided by applicant): Exercise combined with dietary intervention continues to hold the best promise for combating the obesity epidemic. Brisk walking is a recommended and popular form of exercise but weight bearing exercise may be the source of the biomechanical loads that increase the risk of musculoskeletal injury and link obesity and large joint (e.g. knee) osteoarthritis (OA). Thus, prescribing brisk walking as exercise for treating obesity may be biomechanically unsound. However, remarkably little is known about how obesity affects the biomechanical loads involved in walking. The existing walking biomechanics data base does not apply to the 60+% of American adults who are overweight or obese nor to uphill or downhill walking. The long term goal of this research is to derive walking exercise prescriptions for obese adults that minimize lower extremity biomechanical loads while optimizing caloric expenditure and cardiovascular stimulus. Specific Aim 1: Determine how obesity affects the biomechanics of walking. We hypothesize that obesity increases lower extremity joint loads but that moderate inclines combined with decreased walking speed reduce these loads while walking down moderate declines increases lower extremity joint loads. To test these hypotheses, the musculoskeletal biomechanics will be measured across speed on the level, three inclines and one moderate decline using our inclinable, dual-belt force measuring treadmill. Obese and normal weight control subjects of both genders will be studied. Specific Aim 2: Develop more sound guidelines for prescribing walking exercise for obese adults. We hypothesize that for obese adults, slow walking up a moderate incline minimizes knee joint loads while optimizing caloric expenditure and cardiovascular stimulus. To test this hypothesis, we will combine our biomechanical results from Specific Aim 1 with measurements of the metabolic cost of walking and maximal oxygen consumption rates of obese and normal weight adults. We will be able to identify speed and incline combinations that achieve the recommended sustainable moderate aerobic intensity (55-70% of maximal oxygen uptake, VO2max) with the lowest biomechanical loads. The benefits of this research will be more informed, safer and more effective prescriptions of walking as exercise for weight management and cardiovascular health. The walking regimens that we determine should be safer in the shorter term (reduced rates of acute injuries) and longer term (reduced risk of OA). PUBLIC HEALTH RELEVANCE: Obesity is a chief contributor to preventable deaths in the United States and poses a major health challenge associated with increased morbidity and mortality. Brisk walking is a recommended and popular form of exercise for obesity prevention and treatment but may be the source of the biomechanical loads that increase the risk of musculoskeletal injury and link obesity and large joint (e.g. knee) osteoarthritis. The benefits of this research will be more informed, safer and more effective prescriptions of walking as exercise for weight management and cardiovascular health.