BIOMECHANICAL BASIS FOR THE METABOLIC COST OF LOCOMOTION

运动代谢成本的生物力学基础

• 批准号: 6030009
• 负责人: Rodger Kram
• 金额: $ 9.52万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-10 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6030009
• 关键词: basal metabolism; biomechanics; body weight; chordate locomotion; clinical research; gravity; human subject; leg; mechanical stress; metabolism; muscle function; rest

DESCRIPTION (Applicant's abstract): Our overall objective is to synthesize two approaches to quantifying the biomechanical basis for the metabolic energy required for locomotion. The classical approach measures only the mechanical work performed and assumes that the metabolic energy required for isometric muscle activity is negligible. More recently, Kram and Taylor used a comparative zoological approach to test an alternative "cost of generating force" hypothesis. Their results indicate that the generation of muscular force to operate musculoskeletal springs is the dominant energy consuming process and that performing mechanical work has negligible cost. Empirical data supports aspects of each approach, but neither method can comprehensively explain all available data. The logical progression is to further develop the cost of generating force approach on human subjects and to deduce a quantitative, empirically based synthesis of the two approaches. We will test: Hypothesis 1. the metabolic cost of normal human walking is dominated by equal costs of performing external mechanical work on the center mass and of generating force to support body weight and Hypothesis 2. the metabolic cost of normal human running is determined primarily by the cost of generating vertical force to support body weight. Specific aims are to determine what fractions of the total metabolic energy demand are determined by the swinging of the legs, supporting body weight and performing mechanical work on the body center of mass. Experiments will systematically increase or decrease the forces and work required independently and measure the effect of these manipulations on the metabolic energy demand. Experimental manipulations involve simulated hypo-gravity, hyper-gravity, added mass, increased inertia and externally applied horizontal forces. These experiments will be the first that can independently vary and measure mechanical work and force generation. We will then be able to synthesize our results into a coherent overall picture for what muscular actions determine the metabolic cost. These experiments are only now feasible due to newly developed procedures (e.g., simulated hypo-gravity) and biomechanical equipment (e.g., a force measuring treadmill). Locomotion is energetically very expensive in individuals with metabolic (obesity), structural (lower extremity amputees), or gait disorders (cerebral palsy) and thus the energy cost itself can limit mobility. Understanding the basic mechanisms that determine the cost of locomotion will allow for more informed evaluation, treatment, and rehabilitation of these conditions.

描述（申请人的摘要）：我们的总体目标是综合 量化代谢的生物力学基础的两种方法 运动所需的能量。 经典方法仅测量 执行机械功并假设所需的代谢能量 等长肌肉活动可以忽略不计。 最近，克拉姆和泰勒 使用比较动物学方法来测试替代的“成本” 产生力”假说。他们的结果表明， 操作肌肉骨骼弹簧的肌肉力量是主要能量 消耗过程并且执行机械工作的成本可以忽略不计。 经验数据支持每种方法的各个方面，但两种方法都不能 全面解释所有可用数据。 逻辑进展是 进一步发展针对人类受试者的发电成本方法 推断出这两种方法的定量、基于经验的综合。 我们将测试： 假设 1. 人类正常行走的代谢成本为 由执行外部机械功的相同成本主导 中心质量和产生支撑体重的力以及假设 2。 正常人类跑步的代谢成本主要取决于 产生垂直力来支撑体重的成本。 具体目标是 确定总代谢能量需求的比例 由腿部的摆动、支撑体重和 对身体质心进行机械功。 实验将 系统地增加或减少所需的力量和工作 独立地测量这些操作对代谢的影响 能源需求。 实验操作涉及模拟低重力， 超重力、增加质量、增加惯性和外部施加 水平力。 这些实验将是第一个可以 独立改变和测量机械功和力的产生。 我们 然后能够将我们的结果综合成一个连贯的整体图片 哪些肌肉活动决定代谢成本。 这些实验 由于新开发的程序（例如模拟 低重力）和生物力学设备（例如力测量 跑步机）。 对于患有以下疾病的个体来说，运动的能量消耗非常大 代谢（肥胖）、结构（下肢截肢者）或步态 疾病（脑瘫），因此能源成本本身可以限制 流动性。 了解决定成本的基本机制 运动将允许更明智的评估、治疗和 这些条件的康复。