Energetics and mechanics of terrestrial locomotion. I. Metabolic energy consumption as a function of speed and body size in birds and mammals

1982 ◽  
Vol 97 (1) ◽  
pp. 1-21 ◽  
Author(s):  
C. R. Taylor ◽  
N. C. Heglund ◽  
G. M. Maloiy

This series of four papers investigates the link between the energetics and the mechanics of terrestrial locomotion. Two experimental variables are used throughout the study: speed and body size. Mass-specific metabolic rates of running animals can be varied by about tenfold using either variable. This first paper considers metabolic energy consumed during terrestrial locomotion. New data relating rate of oxygen consumption and speed are reported for: eight species of wild and domestic artiodactyls; seven species of carnivores; four species of primates; and one species of rodent. These are combined with previously published data to formulate a new allometric equation relating mass-specific rates of oxygen consumed (VO2/Mb) during locomotion at a constant speed to speed and body mass (based on data from 62 avian and mammalian species): VO2/Mb = 0.533 Mb-0.316.vg + 0.300 Mb-0.303 where VO2/Mb has the units ml O2 s-1 kg-1; Mb is in kg; and vg is in m s-1. This equation can be expressed in terms of mass-specific rates of energy consumption (Emetab/Mb) using the energetic equivalent of 1 ml O2 = 20.1 J because the contribution of anaerobic glycolysis was negligible: Emetab/Mb = 10.7 Mb-0.316.vg + 6.03 Mb-0.303 where Emetab/Mb has the units watts/kg. This new relationship applies equally well to bipeds and quadrupeds and differs little from the allometric equation reported 12 years ago by Taylor, Schmid-Nielsen & Raab (1970). Ninety per cent of the values calculated from this genera equation for the diverse assortment of avian and mammalian species included in this regression fall within 25% of the observed values at the middle of the speed range where measurements were made. This agreement is impressive when one considers that mass-specific rates of oxygen consumption differed by more than 1400% over this size range of animals.

1983 ◽  
Vol 61 (2) ◽  
pp. 281-288 ◽  
Author(s):  
W. Richard Robinson ◽  
Robert Henry Peters ◽  
Jess Zimmermann

Multiple regression analyses of previously published data were performed to describe the effect of variations in body mass (M, in grams) and temperature (t, in degrees Celsius) on the rate of oxygen consumption ([Formula: see text], in millilitres O2 per gram per hour). For homeotherms and poikilotherms, the resultant equations describing standard metabolic rate are [Formula: see text] and [Formula: see text], respectively. The metabolic rate of unicells was described by [Formula: see text], although the temperature term was not statistically significant. When solved at 39 °C, the homeotherm equation is essentially similar to previously published relations. At 20 °C, the poikilotherm relation is slightly higher, and the unicell relation considerably lower, than Hemmingsen's widely cited relations. Enough data were available to provide a statistical description of active reptiles and fish: [Formula: see text]; this relationship may be used to approximate the metabolic rate of actively foraging fish and reptiles. Equations for the standard metabolic rate can serve as components in the calculation of minimal metabolic rates of homeotherms and higher poikilotherms in nature; such values could then be increased by estimates of the additional demands associated with movement, feeding, growth, etc. For unicells and lower vertebrates, standard rates also serve as estimates of free-living rates.


1968 ◽  
Vol 48 (2) ◽  
pp. 427-434
Author(s):  
A. E. BRAFIELD

1. The oxygen consumption of the echiuroid Bonellia viridis has been investigated by means of a continuous-flow polarographic respirometer. 2. The general rate of oxygen consumption per unit dry weight is similar to that characteristic of polychaetes, and declines exponentially with increasing body size. 3. The rate of oxygen consumption rises in the light and falls again if darkness is restored. 4. The oxygen consumption of the isolated proboscis plus that of the isolated body region corresponds closely to that of the entire animal. 5. The oxygen consumption per unit dry weight of the proboscis is considerably higher than that of the body region. 6. The oxygen consumption of an isolated body region increases in the presence of light, but that of an isolated proboscis does not. 7. These findings are discussed in relation to the biology of the animal, observed muscular activity, and the occurrence of the pigment bonellin.


1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.


1957 ◽  
Vol 188 (3) ◽  
pp. 503-506 ◽  
Author(s):  
A. Surtshin ◽  
James K. Cordonnier ◽  
S. Lang

Normal rats as well as thyroparathyroidectomized rats concurrently given thyroxine and an adrenergic blocking dose of Dibenzyline show the expected rise in rate of oxygen consumption. After bilateral adrenal demedullation the resting rate of oxygen consumption is not significantly different from normal, and injection of a large dose of thyroxine either with or without concurrent administration of adrenergic blocking doses of Dibenzyline is followed by a significant rise in the rate of oxygen consumption. Our data and other pertinent published data lend support neither to the claim that the calorigenic effect of exogenous thyroxine is dependent upon the presence of normally acting adrenal medullary hormones nor to the claim that the metabolic changes of thyrotoxicosis are due to the physiological effects of epinephrine and norepinephrine as augmented by the thyroid hormones.


1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.


2020 ◽  
Author(s):  
Tiancheng Zhou ◽  
Caihua Xiong ◽  
Juanjuan Zhang ◽  
Di Hu ◽  
Wenbin Chen ◽  
...  

Abstract Background: Walking and running are the most common means of locomotion in human daily life. People have made advances in developing separate exoskeletons to reduce metabolic rate of walking or running. However, the combined requirements of overcoming fundamental biomechanical differences between the two gaits and minimizing the metabolic penalty of exoskeleton mass make it challenging to develop an exoskeleton that can reduce the metabolic energy for both gaits. Here we show that the metabolic energy of both walking and running can be reduced by regulating the metabolic energy of hip flexion during the common energy consumption period of the two gaits using an unpowered hip exoskeleton. Methods: We analyzed metabolic rates, muscle activities and spatio-temporal parameters from 9 healthy subjects (mean s.t.d; 24.9 ± 3.7 years, 66.9 ± 8.7 kg, 1.76 ± 0.05 m) walking on a treadmill at the speed of 1.5 m×s -1 and running at speed of 2.5 m×s -1 with different spring stiffnesses. After obtaining the optimal spring stiffness, we recruited the participants to walk and run with the optimal stiffness spring at different speeds to demonstrate the generality of the proposed approach. Results: We found that the optimal exoskeleton spring stiffnesses for walking and running were 140 N×m Rad -1 and 210 N×m Rad -1 respectively, corresponding to 8.2% ± 1.5% (mean ± s.e.m, two-sided paired t-test: p < 0.01) and 9.1% ± 1.3% ( p < 0.01) metabolic reductions compared to walking/running without exoskeleton. The metabolic energy within tested speed range can be reduced with the assistance except for low speed walking (1.0 m s -1 ). Participants showed different changes in muscle activities with the assistance of proposed exoskeleton. Conclusions: This paper first demonstrated that metabolic cost of walking and running can be reduced using an unpowered hip exoskeleton to regulate metabolic energy of hip flexion. The design method based on analyzing the common energy consumption characteristics between gaits may inspire future exoskeletons that assist multiple gaits. The results of different changes in muscle activities provided a new insight of human response to the same assistive principle in different gaits (walking and running).


1985 ◽  
Vol 249 (2) ◽  
pp. R262-R265 ◽  
Author(s):  
B. J. Moore ◽  
S. J. Armbruster ◽  
B. A. Horwitz ◽  
J. S. Stern

The rate of oxygen consumption was measured in 2-day Zucker preobese (fa/fa), homozygous (Fa/Fa) lean, and lean rats of unknown genotype (Fa/?) over the ambient temperature range of 26-35 degrees C. Significant differences in body mass were found among the three groups at this early age, the preobese pups having the greatest body mass. To account for body mass differences, the oxygen consumption data were expressed in terms of metabolic body size (ml O2 consumed X g body mass-2/3 X h-1). This mass-independent rate of oxygen consumption was significantly lower in the preobese pups than in the homozygous lean (Fa/Fa) pups at both thermoneutral (33-34 degrees C) and cold (26-27 degrees C) ambient temperatures at which, respectively, minimal and maximal rates of oxygen consumption were observed. This reduction in energy expenditure occurs before the establishment of hyperphagia or decreased levels of activity in the preobese pups. These data support the view that attenuated energy expenditure is a significant contributor to the early development of obesity in the Zucker fatty rat and point to the possibility of defective brown adipose tissue-mediated thermogenesis in the preobese pup.


1953 ◽  
Vol 30 (4) ◽  
pp. 475-491 ◽  
Author(s):  
C. ELLENBY

1. The oxygen consumption and surface area of individual diploid and triploid prepupae of Drosophila melanogaster have been measured, the cells of triploid animals being larger. 2. The mean weights for the types examined are different but their ranges overlap almost completely. By covariance analysis it is shown that, after adjustment for difference in body size, there are no differences in the rates of oxygen consumption. It is concluded that, for these animals, cell size has no influence on the rate of oxygen consumption. 3. The relationships between body weight, surface area, and oxygen consumption have been further investigated. It is shown that, despite the greater inaccuracy of the method by which surface area is determined, oxygen consumption can be predicted more accurately from surface area than from body weight. 4. The results are discussed in relation to an earlier investigation of the oxygen consumption of other genotypes (Ellenby, 1945 a, b). Possible technical causes of certain differences between the two series of results in the relationship of oxygen consumption and body weight are explored; it is concluded, however, that they are almost certainly due to differences, not necessarily genetical, between the animals used in the two series.


2020 ◽  
Vol 14 ◽  
Author(s):  
Ryan-David Reyes ◽  
Rudolf Kobetic ◽  
Mark Nandor ◽  
Nathaniel Makowski ◽  
Musa Audu ◽  
...  

This study assessed the metabolic energy consumption of walking with the external components of a “Muscle-First” Motor Assisted Hybrid Neuroprosthesis (MAHNP), which combines implanted neuromuscular stimulation with a motorized exoskeleton. The “Muscle-First” approach prioritizes generating motion with the wearer's own muscles via electrical stimulation with the actuators assisting on an as-needed basis. The motorized exoskeleton contributes passive resistance torques at both the hip and knee joints of 6Nm and constrains motions to the sagittal plane. For the muscle contractions elicited by neural stimulation to be most effective, the motorized joints need to move freely when not actively assisting the desired motion. This study isolated the effect of the passive resistance or “friction” added at the joints by the assistive motors and transmissions on the metabolic energy consumption of walking in the device. Oxygen consumption was measured on six able-bodied subjects performing 6 min walk tests at three different speeds (0.4, 0.8, and 1.2 m/s) under two different conditions: one with the motors producing no torque to compensate for friction, and the other having the motors injecting power to overcome passive friction based on a feedforward friction model. Average oxygen consumption in the uncompensated condition across all speeds, measured in Metabolic Equivalent of Task (METs), was statistically different than the friction compensated condition. There was an average decrease of 8.8% for METs and 1.9% for heart rate across all speeds. While oxygen consumption was reduced when the brace performed friction compensation, other factors may have a greater contribution to the metabolic energy consumption when using the device. Future studies will assess the effects of gravity compensation on the muscular effort required to lift the weight of the distal segments of the exoskeleton as well as the sagittal plane constraint on walking motions in individuals with spinal cord injuries (SCI).


1951 ◽  
Vol 28 (4) ◽  
pp. 492-507 ◽  
Author(s):  
C. ELLENBY

1. Male Ligia oceanica were used in an investigation of the relationship of body size to rate of oxygen consumption and pleopod beat. 2. Animals varied in weight from 0.04 to 1.03 g. and from 0.95 to 3.1 cm. in length. 3. Body shape does not change significantly over the size range, for length and breadth both increase at the same rate, and pleopod dimensions bear a constant relation to body length. 4. Specific gravity also is constant, for the relation of body weight to the cube of body length shows no trend with increasing size. 5. Oxygen consumption per gram decreases with increasing size and is proportional to the -0.274 Power of body weight. Total oxygen consumption is therefore proportional to the 0.726 power of body weight; but this value does not differ significantly from two-thirds. 6. As shape is constant, surface area is proportional to the square of a linear dimension. It is shown that oxygen consumption per unit of length2 is constant over the size range. Although body length was measured far less accurately than body weight it is shown that it assesses ‘body size’ more accurately. 7. Rate of pleopod beat was measured at 15 and 25°C.; it decreases with the size of the animal. At 15°C. time per beat varies as the 0.66 power of body length, and at 25°C. as the 0.59 power; neither of these values differs significantly from 0.5. Despite the fact that pleopod movement is heavily damped, the rate therefore varies like that of a pendulum. 9. The workof Fox (1936-9) and Fox et al. (1937a)on the rate of oxygen consumption of animals from cold and warmer seas and from different habitats is considered. It is suggested that many of their comparisons are invalidated by differences in body size of the animals concerned, and that, in relation to environment, no basis, theoretical or experimental, has been established for a distinction between ‘nonlocomotory’ and ‘activity’ metabolism.


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