The efficiency of human movement-a statement of the problem 人体运动的效率 - 问题的陈述
PETER R. CAVANAGH and RODGER KRAM 彼得·卡瓦纳 （PETER R. CAVANAGH） 和罗杰·克拉姆 （RODGER KRAM）Biomechanics Laboratory, The Pennsylvania State University, University Park, PA 16802 宾夕法尼亚州立大学生物力学实验室，宾夕法尼亚州大学公园，宾夕法尼亚州 16802
Abstract 抽象
CAVANAGH, PETER R. and RODGER KRAM. The efficiency of human movement-a statement of the problem. Med. Sci. Sports Exerc., Vol. 17, No. 3, pp. 304-308, 1985. This paper is an introduction to a multidisciplinary series of papers on the efficiency of human movement. The problem is posed by citing the example of the large variation in oxygen uptake (per kg body weight) within a typical group of subjects running at the same submaximal speed. An analog of the possible causes of this variation is presented where “set points” for biomechanical, physiological, psychological, biochemical, and other factors combine in series to influence the overall energy cost. The various definitions of “efficiency” and “economy” are considered at the whole body and the isolated muscle level, and a discussion of baseline subtraction is presented. The concept of “effectiveness” is reviewed to illustrate the interaction of skilled performance and energy cost. It is recommended that the terms “muscular efficiency,” “muscle efficiency,” “economy,” and “effectiveness” be used in their respective contexts to replace the current diversity of overlapping and, at times, confusing terminology. 卡瓦纳、彼得 R. 和罗杰·克拉姆。人体运动的效率 - 问题的陈述。Med. Sci. Sports Exerc.，第 17 卷，第 3 期，第 304-308 页，1985 年。本文是关于人体运动效率的多学科系列论文的介绍。这个问题是通过引用以相同的次最大速度跑步的典型受试者组中摄氧量（每公斤体重）的巨大变化来提出的。提出了这种变化的可能原因的类似示例，其中生物力学、生理、心理、生化和其他因素的“设定点”串联起来影响整体能源成本。在全身和孤立的肌肉水平考虑了“效率”和“经济性”的各种定义，并讨论了基线减法。回顾了“有效性”的概念，以说明技能表现和能源成本之间的相互作用。建议在各自的上下文中使用术语“肌肉效率”、“肌肉效率”、“经济”和“有效性”，以取代当前重叠且有时令人困惑的术语的多样性。
To the lay person, “efficiency of movement” is not only perceived to be a simple concept, but it is also thought to be an easily recognizable characteristic. Take, for example, the case of Emil Zatopek, the great Czech runner who was the only athlete ever to win the 5000-m,10,000-m5000-\mathrm{m}, 10,000-\mathrm{m} and marathon in the same Olympic Games. He was universally thought to be an “inefficient” runner. Contemporary journalists described Za topek’s victorious 5000-m run in the Helsinki games variously as: “(running) like a man with a noose about his neck,” “all grimaces and awkwardness above the waist,” and “(looking) as if every step will be his last.” Since there appears to have been little or no experimental research conducted on Zatopek, we shall never know whether he was really “inefficient,” but the question of whether “efficiency” in running can be recognized deserves to be addressed. It is instructive to have knowl- 对于外行人来说，“运动效率”不仅被认为是一个简单的概念，而且还被认为是一个容易识别的特征。以伟大的捷克跑步运动员 Emil Zatopek 为例，他是唯一一位在同一届奥运会上赢得 5000-m,10,000-m5000-\mathrm{m}, 10,000-\mathrm{m} 马拉松冠军的运动员。人们普遍认为他是一个“效率低下”的跑步者。当代记者将扎托佩克在赫尔辛基奥运会上获胜的 5000 米跑描述为：“（奔跑）就像一个脖子上套着套索的人”，“腰部以上都是鬼脸和尴尬”，以及“（看起来）好像每一步都是他的最后一步”。由于对扎托佩克的实验研究似乎很少或根本没有进行，我们永远无法知道他是否真的“效率低下”，但是否可以认识到跑步中的“效率”的问题值得解决。了解该知识是有启发性的
edgeable observers (such as coaches, physiologists, and biomechanists) review films of athletes performing endurance events and ask them to rate the athletes on the appearance of “efficiency.” When these ratings are compared to the submaximal oxygen uptake, it is a common occurrence for an athlete ranked visually as quite efficient to expend more energy (per kg body weight) than those rated visually as less “efficient.” 易走的观察者（如教练、生理学家和生物力学家）回顾运动员进行耐力项目的影片，并要求他们根据运动员的“效率”外观对运动员进行评分。当将这些评级与次最大摄氧量进行比较时，视觉上被评为相当高效的运动员比视觉上被评为“效率”较低的运动员消耗更多的能量（每公斤体重）是很常见的。
This paper and the following contributions (2,6,12,18)(2,6,12,18) represent the proceedings of a multidisciplinary symposium designed to examine the topic of “efficiency of human movement.” It is important that this topic be approached from many perspectives, because sport scientists in each of the subdisciplines have traditionally ascribed the reasons for variation in “efficiency” to another subdiscipline. 本文和以下贡献 (2,6,12,18)(2,6,12,18) 代表了旨在研究“人类运动效率”主题的多学科研讨会的会议记录。从多个角度来探讨这个话题很重要，因为每个子学科的体育科学家传统上将“效率”变化的原因归咎于另一个子学科。
Perhaps the best introduction to the problem of varying “efficiency” is to examine the oxygen uptakes of a random sample of subjects during submaximal running. Various equations exist to predict oxygen uptake at a given speed (5,15)(5,15). While these equations give representative values for the population mean, reliance on these values disguises the fact that there is enormous intersubject variation in the submaximal oxygen uptake at a given workload. Costill et al. (4) found a variation of approximately 12%12 \% in V^(˙)_(2" submax ")\dot{V}_{2 \text { submax }} in a sample of 16 trained distance runners running at 4.46m*sec^(-1)4.46 \mathrm{~m} \cdot \mathrm{sec}^{-1}, while Williams (17) reported a variation of 17%17 \% in a group of 31 recreational runners at 3.57 m*sec^(-1)\mathrm{m} \cdot \mathrm{sec}^{-1}. 也许对变化“效率”问题的最佳介绍是检查随机样本受试者在次最大跑步期间的摄氧量。存在各种方程式来预测给定速度 (5,15)(5,15) 下的摄氧量。虽然这些方程给出了总体平均值的代表性值，但依赖这些值掩盖了这样一个事实，即在给定工作负载下，次最大摄氧量存在巨大的受试者间变化。Costill 等人 （4） 在 16 名训练有素的长跑运动员的样本中发现了大约 12%12 \% in V^(˙)_(2" submax ")\dot{V}_{2 \text { submax }} 的差异，而 Williams （17） 报告了一组 31 名休闲跑步者的 3.57 的差异 17%17 \%m*sec^(-1)\mathrm{m} \cdot \mathrm{sec}^{-1} 。 4.46m*sec^(-1)4.46 \mathrm{~m} \cdot \mathrm{sec}^{-1}
It is not possible to precisely partition this variation into particular factors (such as biomechanical, physiological, psychological, and biochemical), because each individual probably has a unique set of coefficients for the factors contributing to efficient performance. 不可能将这种变化精确地划分为特定的因素（例如生物力学、生理、心理和生化），因为每个人可能都有一组独特的系数，这些系数是影响高效表现的因素。
An illustrative electrical analog of the problem is shown in Figure 1. The voltage, VV, in the circuit corresponds to the running speed, and the electrical power consumption, PP, is analogous to the metabolic energy cost. Each of the factors that contribute to efficient 图 1 显示了该问题的示例性电气模拟。电路中的电压 VV 对应于运行速度，而电能消耗 PP 则类似于代谢能成本。有助于提高效率的每个因素
Figure 1-An electrical analog of the factors affecting the efficiency of human movement. The running speed has as its analog the voltage, VV, and each of the factors contributes a resistance, RI through R5, which thus determines the current, ii, flowing in the circuit. The greater the efficiency the higher the resistance. In this model, electrical power dissipated, PP, represents the metabolic cost of the task. 图 1 - 影响人体运动效率的因素的电气模拟。运行速度的模拟是电压 VV ，每个因素都贡献了一个电阻 RI 到 R5，从而决定了电路中流动的电流 ii 。效率越高，电阻就越大。在此模型中，耗散的电力 PP 表示任务的代谢成本。
performance is represented by one of five variable resistors in series. The more efficient the “setting” for a particular factor, the higher the resistance and therefore the lower the current flow. The overall electrical power consumption, and its analog, the metabolic energy cost, is then determined by the combined series resistance in the circuit. Although running was chosen here as the activity, the concepts shown apply equally well to other forms of submaximal exercise. 性能由五个串联的可变电阻器之一表示。特定因子的“设置”越有效，电阻就越高，因此电流越低。总功耗及其类似物代谢能成本由电路中的组合串联电阻决定。虽然这里选择跑步作为活动，但所显示的概念同样适用于其他形式的次极量锻炼。
The purpose of this introductory paper is to provide a critical examination of the terminology used in the literature on “efficiency of movement” as a background to the more specialized papers from the various subdisciplines which follow. 这篇介绍性论文的目的是对文献中关于“运动效率”的术语进行批判性检查，作为随后各个子学科中更专业论文的背景。
MUSCULAR EFFICIENCY 肌肉效率
When one attempts to formally quantify “efficiency” (which has been intentionally qualified with quotation marks so far), the first problem encountered is a semantic one. The dictionary definition-work done divided by energy expended-is a straightforward one, yet exercise scientists have created a bewildering array of different definitions. The variety of definitions is rivalled only by the vast range of values for the various measures. It is appropriate to begin this review with a collation of definitions for efficiency found in the literature. 当人们试图正式量化“效率”（到目前为止，它一直被故意用引号限定）时，遇到的第一个问题是语义问题。字典定义——完成的工作除以消耗的能量——很简单，但运动科学家已经创造了一系列令人眼花缭乱的不同定义。定义的多样性只能与各种度量值的广泛范围相媲美。从文献中发现的效率定义的整理开始这篇综述是合适的。
Muscular efficiency has been defined by Stainsby et al. (14) as the ratio of the mechanical work to the metabolic energy expended. A synonymous term used by other investigators is gross efficiency (9). A range of values from -120%-120 \% for downhill treadmill walking (11) Stainsby 等人 （14） 将肌肉效率定义为机械功与消耗的代谢能量的比率。其他研究人员使用的同义词是总效率 （9）。用于 downhill treadmill walking （11） 的值范围 -120%-120 \%
to +250%+250 \% for level treadmill walking (13) have been reported for muscular efficiency. Since the denominator used by both the above groups of investigators was the same-gross submaximal oxygen uptake-the cause for most of the enormous variation lies in the choice of the numerator. Thus, the problem with the use of this definition is one that must be resolved by modifying the methods used to quantify mechanical work. This topic is addressed at length in the companion paper by Williams (18). 据报道 +250%+250 \% ，对于水平跑步机行走 （13） 的肌肉效率。由于上述两组研究人员使用的分母是相同的——总次最大摄氧量——大部分巨大变化的原因在于分子的选择。因此，使用这个定义的问题是必须通过修改用于量化机械功的方法来解决。这个话题在 Williams （18） 的配套论文中详细讨论了。
THE BASELINE PROBLEM 基线问题
A first refinement to the term muscular efficiency attempts to account for the fact that more work is always done to perform a given task than can be measured by an ergometer. Consider the typical laboratory situation involving a cycle ergometer. When the subject is sitting at rest on the bicycle, the oxygen uptake might be 0.301*min^(-1)0.301 \cdot \mathrm{~min}^{-1}. Clearly, the subject is performing work for such functions as respiration, circulation, ion transport, and stabilization of body parts-which we shall call physiological maintenance work-but the ergometer indicates that no work is being done. When the subject begins pedalling at 60 rpm with no resistive load, the oxygen uptake might be 0.451*min^(-1)0.451 \cdot \mathrm{~min}^{-1}, yet the ergometer still indicates zero work. In the later case, an analysis of external work (that work done to change the energy levels of the limb segments) using the analysis techniques of Fenn (7) would give an estimate of work done, yet it would still not account completely for all of the work associated with the task. 对肌肉效率一词的第一次改进试图解释这样一个事实，即执行给定任务总是比测力计可以测量的功更多。考虑涉及自行车测力计的典型实验室情况。当受试者坐在自行车上休息时，摄氧量可能是 0.301*min^(-1)0.301 \cdot \mathrm{~min}^{-1} 。显然，受试者正在执行呼吸、循环、离子传输和身体部位稳定等功能的工作——我们称之为生理维持工作——但测力计显示没有做任何工作。当受试者在没有阻力负载的情况下以 60 rpm 的速度开始踩踏板时，摄氧量可能是 0.451*min^(-1)0.451 \cdot \mathrm{~min}^{-1} ，但测力计仍然显示零功。在后一种情况下，使用 Fenn （7） 的分析技术对外部功（为改变肢体节段的能级所做的功）进行分析将给出已完成功的估计值，但它仍然不能完全解释与任务相关的所有功。
If a resistive load is finally applied to the bicycle (e.g., 600kpm*min^(-1)600 \mathrm{kpm} \cdot \mathrm{min}^{-1} at 60 rpm ), the oxygen uptake might rise to 1.501*min^(-1)1.501 \cdot \mathrm{~min}^{-1}. Given the preceding discussion, this oxygen uptake has been suggested by some investigators to consist of three components: that necessary to maintain the body in position on the bicycle and the physiological maintenance work, that required to move the legs at zero load through the prescribed pattern of movement, and that necessary to overcome the resistive load. 如果最终对自行车施加电阻负载（例如， 600kpm*min^(-1)600 \mathrm{kpm} \cdot \mathrm{min}^{-1} 在 60 rpm 时），则吸氧量可能会上升到 1.501*min^(-1)1.501 \cdot \mathrm{~min}^{-1} 。鉴于前面的讨论，一些研究人员建议这种摄氧量由三个部分组成：在自行车上保持身体位置所必需的和生理维护工作，需要通过规定的运动模式以零负荷移动双腿，以及克服阻力负荷所必需的。
Three types of definitions, shown in Figure 2, which subtract the oxygen cost of these various componentssometimes referred to as baselines-have been suggested by Gaesser and Brooks (8). Gaesser 和 Brooks （8） 提出了三种类型的定义，如图 2 所示，它们减去了这些不同成分（有时称为基线）的氧成本。
In net efficiency, the denominator is defined as “the energy expended above that at rest.” Work efficiency or apparent efficiency uses as the denominator “energy expended above that used in cycling at zero load.” Delta efficiency is defined as the average gradient of the energy expended vs work done curve between two specified limits for the work done. 在净效率中，分母被定义为“在静止时消耗的能量”。工作效率或表观效率使用“消耗的能量高于零负载骑行时使用的能量”作为分母。Delta 效率定义为已完成功的两个指定限制之间的消耗能量与完成工作量曲线的平均梯度。
Serious problems exist with each of the modified definitions. Stainsby et al. (14) contend that the idea of a constant physiological baseline is invalid, and they 每个修改后的定义都存在严重问题。Stainsby 等人 （14） 认为恒定的生理基线的想法是无效的，他们
Figure 2-Two attempts to define baselines for energy cost during cycling. RR represents the energy required for physiological maintenance work at rest; UPU P represents the energy required for the above plus that needed to change the energy levels of the body segments in unloaded pedalling. Delta efficiency is defined as the ratio of delta work to delta energy. There are objections to each of these definitions. From Stainsby et al. (14). 图 2 - 两次尝试定义循环期间能源成本的基线。 RR 代表静息时生理维持工作所需的能量; UPU P 代表上述 PLUS 在空载踩踏中改变身体各段能量水平所需的能量。Delta 效率定义为 delta 功与 delta 能量的比率。这些定义中的每一个都有异议。来自 Stainsby 等人 （14）。
gave several examples of physiological support processes for which the energy cost does not remain constant during exercise. A further objection is that, while measuring energy cost at zero load is possible for activities such as cycling on an ergometer, similar measures during treadmill running are difficult to define. 给出了几个生理支持过程的例子，这些过程的能量消耗在运动过程中不会保持不变。进一步的反对意见是，虽然在测力计上骑自行车等活动可以在零负载下测量能源成本，但在跑步机跑步期间的类似措施很难定义。
MUSCLE EFFICIENCY 肌肉效率
While the foregoing definitions were all calculated from measurements on gross human movements, the question of isolated muscle efficiency must also be investigated. The two processes that involve conversion of energy from one form to another are referred to as phosphorylation coupling and contraction coupling (16). In the former, energy stored in metabolic substrates is transformed into high-energy phosphates with an efficiency of approximately 60%60 \%. The strict definition of this “efficiency of phosphorylative coupling” is: 虽然上述定义都是根据人体粗大运动的测量计算得出的，但也必须研究孤立肌肉效率的问题。涉及能量从一种形式转换为另一种形式的两个过程称为磷酸化偶联和收缩偶联 （16）。在前者中，储存在代谢底物中的能量转化为高能磷酸盐，效率约为 60%60 \% 。这个“磷酸化偶联效率”的严格定义是：
(" Free energy conserved as ATP ")/(" Free energy of oxidized foodstuff ")xx100\frac{\text { Free energy conserved as ATP }}{\text { Free energy of oxidized foodstuff }} \times 100
In contraction coupling, the energy stored in phosphates is converted into tension with an efficiency of approximately 49%49 \% (16). Thus, the efficiency for the whole process of converting foodstuff into tension is the product of the efficiencies of these two processes. This product has been called “muscle efficiency,” which must be clearly distinguished from the term “muscular efficiency” defined above. The maximum value calculated for “muscle efficiency” in isolated preparations is approximately 29%29 \% (the product of 0.60 and 0.49 ). Historically, muscle and muscular efficiency have been confused, because the maximum value of muscular 在收缩耦合中，储存在磷酸盐中的能量以大约 49%49 \% （16） 的效率转化为张力。因此，将食品转化为张力的整个过程的效率是这两个过程效率的乘积。该产品被称为“肌肉效率”，必须与上面定义的术语“肌肉效率”明确区分。在分离制剂中计算的“肌肉效率”的最大值约为 29%29 \% （0.60 和 0.49 的乘积）。从历史上看，肌肉和肌肉效率一直被混淆，因为肌肉的最大值
efficiency during concentric muscular work has also been reported as approximately 30%30 \%. Stainsby et al. (14) emphasize that the similarity in the numerical values has no physiological basis. 据报道，同心肌肉工作期间的效率约为 30%30 \% .Stainsby 等人 （14） 强调数值的相似性没有生理学基础。
ECONOMY 经济
Since fractional utilization of V_(O_(2)" max ")\mathrm{V}_{\mathrm{O}_{2} \text { max }} has been found to be an important determinant of endurance performance (4), it is generally agreed that, regardless of the subject’s V^(˙)_(2" max ")\dot{\mathrm{V}}_{2 \text { max }}, the lower the submaximal oxygen uptake for a given workload the better. As previously discussed, individuals vary considerably in the amount of energy expended to perform the same submaximal task, such as running at a particular speed. It must be clearly understood that these differences in energy cost cannot immediately be interpreted as differences in efficiency. Running speed, for example, is a highly unreliable measure of work done. A runner with a high vv^(˙)O_(2" submax ")\dot{\vee} \mathrm{O}_{2 \text { submax }} at a given speed may indeed be performing more mechanical work than one with a lower oxygen cost, and both may therefore be operating at precisely the same muscular efficiency. In practical terms, successful performance in endurance events is highly related to the energy cost (3) and is independent of the actual work done. Because of this practical significance and because of the difficulty in obtaining accurate estimates of work done, the term economy-defined as the submaximal oxygen uptake per unit body weight ( V^(˙)_("2submax ")\dot{\mathrm{V}}_{\text {2submax }} ) required to perform a given task has become almost universally accepted as the physiological criterion for “efficient” performance. 由于 V_(O_(2)" max ")\mathrm{V}_{\mathrm{O}_{2} \text { max }} 已发现 的分数利用是耐力表现的重要决定因素 （4），因此普遍认为，无论受试者的 V^(˙)_(2" max ")\dot{\mathrm{V}}_{2 \text { max }} 如何，给定工作量的次最大摄氧量越低越好。如前所述，个体在执行相同的次最大任务（例如以特定速度跑步）所消耗的能量方面差异很大。必须清楚地理解，这些能源成本的差异不能立即解释为效率的差异。例如，跑步速度是衡量已完成功的非常不可靠的指标。在给定速度下速度较高的 vv^(˙)O_(2" submax ")\dot{\vee} \mathrm{O}_{2 \text { submax }} 跑步者可能确实比氧气成本较低的跑步者执行更多的机械工作，因此两者可能以完全相同的肌肉效率运行。在实践中，耐力赛的成功表现与能源成本 （3） 高度相关，并且与实际完成的工作无关。由于这一实际意义以及难以准确估计所完成的工作，术语经济性定义为执行给定任务所需的每单位体重 （ V^(˙)_("2submax ")\dot{\mathrm{V}}_{\text {2submax }} ） 的次最大摄氧量，几乎被普遍接受为“高效”绩效的生理标准。
EFFECTIVENESS 有效性
In the link between isolated muscle and the production of external work by the human limb, there are two locations where the relationship between external work done and energy cost can be modified. The first is the link between muscles and the skeleton. Most muscles acting across human joints work at a mechanical disadvantage; for example, the force in the biceps brachii may be 10 times greater than the force that can be sustained at the hand (1). There is little quantitative information in the literature concerning individual differences in muscle and joint geometry, and this may be an important source of variation in economy between different individuals. 在离体肌肉与人体肢体产生外部功之间的联系中，有两个位置可以改变完成的外部功与能源成本之间的关系。首先是肌肉和骨骼之间的联系。大多数作用于人体关节的肌肉在机械上工作时处于劣势;例如，肱二头肌中的力可能比手上可以承受的力大 10 倍 （1）。文献中关于肌肉和关节几何形状个体差异的定量信息很少，这可能是不同个体之间经济差异的重要来源。
The second link that involves attenuation of force is that between the human and the ergometer. Frequently, application of force in an optimal direction is thought of as a major component of skilled performance. The concept of “unused” or “wasted” force is one that deserves more attention in the discussion of efficiency. 涉及力衰减的第二个环节是人体和测力计之间的环节。通常，在最佳方向上施加力被认为是熟练表现的主要组成部分。在讨论效率时，“未使用”或“浪费”的力的概念值得更多关注。
In cycling, the term force effectiveness has been coined (10) to quantify the relationship between the 在骑行中，创造了 Force effectiveness 一词 （10） 来量化
Submitted for publication October, 1983. 1983 年 10 月提交出版。
Accepted for publication June, 1984. 1984 年 6 月接受出版。
