scholarly journals Gait changes in a line of mice artificially selected for longer limbs

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3008 ◽  
Author(s):  
Leah M. Sparrow ◽  
Emily Pellatt ◽  
Sabrina S. Yu ◽  
David A. Raichlen ◽  
Herman Pontzer ◽  
...  
Keyword(s):  
Stride Length ◽  
Stance Phase ◽  
Metabolic Cost ◽  
Limb Length ◽  
Stride Frequency ◽  
Practical Reasons ◽  
Cost Of Transport ◽  
Terrestrial Locomotion ◽  
Hind Limbs ◽  
Body Sizes

In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged mouse line created through artificial selection, and in random-bred, mass-matched Control mice raised under identical conditions. We used a gait treadmill to test the hypothesis that Longshanks have longer stance phases and stride lengths, and decreased stride frequencies in both fore- and hind limbs, compared with Controls. Our results indicate that gait differs significantly between the two groups. Specifically, and as hypothesized, stance duration and stride length are 8–10% greater in Longshanks, while stride frequency is 8% lower than in Controls. However, there was no difference in the touch-down timing and sequence of the paws between the two lines. Taken together, these data suggest that, for a given speed, Longshanks mice take significantly fewer, longer steps to cover the same distance or running time compared to Controls, with important implications for other measures of variation among individuals in whole-organism performance, such as the metabolic cost of transport.

scholarly journals Phylogenetic and Ontogenetic determinants of sprint performance in some diurnal Kalahari Lizards

Koedoe ◽  
1982 ◽  
Vol 25 (1) ◽  
Author(s):  
R. B Huey
Keyword(s):  
Stride Length ◽  
Sprint Performance ◽  
Stride Frequency ◽  
Maximum Speed ◽  
Body Proportions ◽  
Body Sizes

Sprint capacities (maximum speed, acceleration, stride length, stride frequency) of diurnal lizards from the Kalahari were measured on sandy substrates in the laboratory. Despite major interfamilial differences in body sizes and in body proportions, measures of sprint capacity were remarkably similar among families: some heavy bodied skinks ran as fast as did some sleek lacertids. Sprint capacities change during ontogeny in lizards. Maximum speed, stride length, and possibly acceleration all increase with size and presumably with age.

scholarly journals Energetic cost of locomotion as a function of ambient temperature and during growth in the marsupial Potorous tridactylus.

1993 ◽  
Vol 174 (1) ◽  
pp. 81-95
Author(s):  
R V Baudinette ◽  
E A Halpern ◽  
D S Hinds
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Multiple Regression ◽  
Stride Length ◽  
Energy Use ◽  
Linear Increase ◽  
Stride Frequency ◽  
Energetic Cost ◽  
Cost Of Transport ◽  
Cost Of Locomotion

In the marsupial, the potoroo, multiple regression analysis shows that ambient temperature makes a minor (2%) contribution towards variation in oxygen consumption with speed. This suggests that the heat generated during running is substituted for heat which would otherwise have to be generated for temperature regulation. Maximum levels of oxygen consumption are also temperature-independent over the range 5-25 degrees C, but plasma lactate concentrations at the conclusion of exercise significantly increase with ambient temperature. Adult potoroos show a linear increase in oxygen consumption with speed, and multiple regression indicates that the most significant factor affecting energy use during running is stride length. Juvenile potoroos have an incremental cost of locomotion about 40% lower than that predicted on the basis of body mass. The smaller animals meet the demands of increasing speed by increasing stride length rather than stride frequency, as would be expected in a smaller species. Our results show that juvenile potoroos diverge significantly from models based only on adult animals in incremental changes in stride frequency, length and the cost of transport, suggesting that they are not simply scaled-down adults.

scholarly journals LOCOMOZIONE UMANA E ANIMALE A DIFFERENTI GRAVITÀ: ADATTAMENTI BIOMECCANICI ED EFFETTI METABOLICI

2020 ◽  
Author(s):  
Alberto Enrico Minetti
Keyword(s):  
Outer Space ◽  
Metabolic Cost ◽  
Biomechanical Analysis ◽  
The Moon ◽  
Low Gravity ◽  
Cost Of Transport ◽  
Terrestrial Locomotion ◽  
The World ◽  
Potential Adaptation ◽  
Gravity Acceleration

A few years before Apollo Missions to Moon, locomotion physiologists promoted research and discussion about the potential adaptation of human body, the musculo-skeletal apparatus in particular, to an environment subject to a much smaller gravity acceleration than on Earth. Rodolfo Margaria and Giovanni Cavagna, who had just started investigating the fundamental mechanical paradigms of terrestrial locomotion, built a gravity-emulation facility in a 15 m tall vent shaft in Milano to study how jumping ability was affected by low-gravity. The combined knowledge led them to correctly predict that humans on the Moon would have walked at a very low pace and the alternative to an impaired running would have been a bouncing gait like hopping. Since then, other scientists around the world kept on researching on this subject, both experimentally and through mathematical models. Models based on ‘dynamic similarity’ (Froude Number) have confirmed that spontaneous locomotion adopted by astronauts was predictable. Recent biomechanical and metabolic experiments in the rebuilt emulation facility in Milano indicated that gaits with very different economy on Earth (running, skipping and hopping range from 2x to 10x, when compared to walking) progressively tend to have the same cost of transport when gravity decreases, and they are all alike at Moon gravity. This suggests that the energy devoted to sustain body weight represents a crucial determinant in the propulsion economy. Together with further biomechanical analysis, these data from emulated outer space are promising clues toward a better understanding of still unsolved mysteries of terrestrial locomotion (as the speed independence of metabolic cost of running).

scholarly journals Energetics of terrestrial locomotion of the platypus Ornithorhynchus anatinus

2001 ◽  
Vol 204 (4) ◽  
pp. 797-803 ◽  
Author(s):  
F.E. Fish ◽  
P.B. Frappell ◽  
R.V. Baudinette ◽  
P.M. MacFarlane
Keyword(s):  
Metabolic Rate ◽  
Metabolic Cost ◽  
Standard Metabolic Rate ◽  
Cost Of Transport ◽  
Terrestrial Locomotion ◽  
Terrestrial Mammals ◽  
Video Recordings ◽  
Ornithorhynchus Anatinus ◽  
The Cost ◽  
Limb Structure

The platypus Ornithorhynchus anatinus Shaw displays specializations in its limb structure for swimming that could negatively affect its terrestrial locomotion. Platypuses walked on a treadmill at speeds of 0.19-1.08 m × s(−1). Video recordings were used for gait analysis, and the metabolic rate of terrestrial locomotion was studied by measuring oxygen consumption. Platypuses used walking gaits (duty factor >0.50) with a sprawled stance. To limit any potential interference from the extensive webbing on the forefeet, platypuses walk on their knuckles. Metabolic rate increased linearly over a 2.4-fold range with increasing walking speed in a manner similar to that of terrestrial mammals, but was low as a result of the relatively low standard metabolic rate of this monotreme. The dimensionless cost of transport decreased with increasing speed to a minimum of 0.79. Compared with the cost of transport for swimming, the metabolic cost for terrestrial locomotion was 2.1 times greater. This difference suggests that the platypus may pay a price in terrestrial locomotion by being more aquatically adapted than other semi-aquatic or terrestrial mammals.

scholarly journals Running Stride Length And Rate Are Changed And Mechanical Efficiency Is Preserved After Cycling In Middle-Level Triathletes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rodrigo Gomes da Rosa ◽  
Henrique Bianchi de Oliveira ◽  
Luca Paolo Ardigò ◽  
Natalia Andrea Gomeñuka ◽  
Gabriela Fischer ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Stride Length ◽  
Metabolic Cost ◽  
Mechanical Efficiency ◽  
Middle Level ◽  
Moderate Intensity ◽  
Cost Of Transport ◽  
Spatiotemporal Parameters ◽  
The Cost

AbstractAlthough cycling impairs the subsequent metabolic cost and performance of running in some triathletes, the consequences on mechanical efficiency (Eff) and kinetic and potential energy fluctuations of the body center of mass are still unknown. The aim of this study was to investigate the effects of previous cycling on the cost-of-transport, Eff, mechanical energy fluctuations (Wtot), spring stiffness (Kleg and Kvert) and spatiotemporal parameters. Fourteen middle-level triathletes (mean ± SD: maximal oxygen uptake, $$\dot{{\rm{V}}}$$V̇O2max = 65.3 ± 2.7 ml.kg−1.min−1, age = 30 ± 5 years, practice time = 6.8 ± 3.0 years) performed four tests. Two maximal oxygen uptake tests on a cycle ergometer and treadmill, and two submaximal 20-minute running tests (14 km.h−1) with (prior-cycling) and without (control) a previous submaximal 30-minute cycling test. No differences were observed between the control and post-cycling groups in Eff or Wtot. The Eff remains unchanged between conditions. On the other hand, the Kvert (20.2 vs 24.4 kN.m−1) and Kleg (7.1 vs 8.2 kN.m−1, p < 0.05) were lower and the cost-of-transport was higher (p = 0.018, 3.71 vs 3.31 J.kg−1.m−1) when running was preceded by cycling. Significantly higher stride frequency (p < 0.05, 1.46 vs 1.43 Hz) and lower stride length (p < 0.05, 2.60 vs 2.65 m) were observed in the running after cycling condition in comparison with control condition. Mechanical adjustments were needed to maintain the Eff, even resulting in an impaired metabolic cost after cycling performed at moderate intensity. These findings are compatible with the concept that specific adjustments in spatiotemporal parameters preserve the Eff when running is preceded by cycling in middle-level triathletes, though the cost-of-transport increased.

scholarly journals The efficacy of a motorized lower-limb prosthetic device: a pilot study

2020 ◽  
Author(s):  
Jo Ghillebert ◽  
Joost Geeroms ◽  
Louis Flynn ◽  
Sander De Bock ◽  
Renée Govaerts ◽  
...  
Keyword(s):  
Stride Length ◽  
Metabolic Cost ◽  
Functional Independence ◽  
Stair Climbing ◽  
Daily Activities ◽  
The Novel ◽  
Transfemoral Amputation ◽  
Active Device ◽  
Cost Of Transport ◽  
Experimental Trial

Abstract BACKGROUND Performing daily activities is challenging for individuals with a transfemoral amputation. Technological advancements in prosthetic prototypes aim at improving functional independence. A state-of-the-art active device, the CYBERLEGs-gamma (CLs-ɣ) prosthesis, consisting of powered ankle and knee joints, has been designed and constructed. The control system combines pressure-sensitive insoles and inertial motor units to synchronize both joints to work together. To date, the novel device has not een clinically evaluated. Therefore, the objective of this study was to investigate the efficacy of the CLs-ɣ prosthesis during daily activities compared to current passive and quasi-passive devices . METHODS Participants performed a familiarization trial, an experimental trial with the current prosthesis, three adaptation trials and an experimental trial with the CLs-ɣ prosthesis. Participants completed a stair climbing test, a timed-up & go test, a sit to stand test, a two-minute dual task (i.e. the psychomotor vigilance task during treadmill walking) and a six-minute treadmill walk test at normal speed. Nonparametric Wilcoxon-signed rank tests were conducted with critical alpha set at 0.05. RESULTS Eight individuals with a transfemoral amputation (age: 55 ± 15 years, K-level 3) were included. Stride length significantly increased during walking with the CLs-ɣ prosthesis (p=0.012) because of a greater step length of the amputated leg (p=0.035). Normal walking speed was significantly slower (p=0.018), the net metabolic cost of transport was significantly higher (p=0.028) and reaction time significantly worsened (p=0.012) when walking with the CLs-ɣ compared to the current prosthesis. When participants took stairs, they adopted a step-over-step strategy with the CLs-ɣ prosthesis in contrast to step-by-step wearing the current prosthesis. CONCLUSION S A higher physical effort and cognitive demand were required during activities wearing the novel motorized prosthesis. Although performance outcome measures did not improve, participants had a greater stride length and better simulated able-bodied stair ambulation.

A model of scale effects in mammalian quadrupedal running

2002 ◽  
Vol 205 (7) ◽  
pp. 959-967 ◽  
Author(s):  
Hugh M. Herr ◽  
Gregory T. Huang ◽  
Thomas A. McMahon
Keyword(s):  
Time Course ◽  
Scale Effects ◽  
Metabolic Cost ◽  
Integrative Model ◽  
Stride Frequency ◽  
Published Data ◽  
Model Parameters ◽  
Cost Of Transport ◽  
Vertical Stiffness ◽  
Leg Stiffness

SUMMARYAlthough the effects of body size on mammalian locomotion are well documented, the underlying mechanisms are not fully understood. Here, we present a computational model of the mechanics, control and energetics that unifies some well-known scale effects in running quadrupeds. The model consists of dynamic, physics-based simulations of six running mammals ranging in size from a chipmunk to a horse (0.115-676 kg). The `virtual animals' are made up of rigid segments (head, trunk and four legs) linked by joints and are similar in morphology to particular species. In the model, each stance limb acts as a spring operating within a narrow range of stiffness, forward motion is powered and controlled by active hip and shoulder torques, and metabolic cost is predicted from the time course of supporting body weight. Model parameters that are important for stability (joint stiffnesses,limb-retraction times and target positions and velocities of the limbs) are selected such that (i) running kinematics (aerial height, forward speed and body pitch) is smooth and periodic and (ii) overall leg stiffness is in agreement with published data. Both trotting and galloping gaits are modeled,and comparisons across size are made at speeds that are physiologically similar among species. Model predictions are in agreement with data on vertical stiffness, limb angles, metabolic cost of transport, stride frequency, peak force and duty factor. This work supports the idea that a single, integrative model can predict important features of running across size by employing simple strategies to control overall leg stiffness. More broadly, the model provides a quantitative framework for testing hypotheses that relate limb control, stability and metabolic cost.

scholarly journals Limitations of Foot-Worn Sensors for Assessing Running Power

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4952
Author(s):  
Tobias Baumgartner ◽  
Steffen Held ◽  
Stefanie Klatt ◽  
Lars Donath
Keyword(s):  
Time Use ◽  
Stride Length ◽  
Metabolic Cost ◽  
Running Economy ◽  
Accelerometer Data ◽  
Gait Characteristics ◽  
Significant Difference ◽  
Metabolic Costs ◽  
Ground Contact Time ◽  
Training Signal

Running power as measured by foot-worn sensors is considered to be associated with the metabolic cost of running. In this study, we show that running economy needs to be taken into account when deriving metabolic cost from accelerometer data. We administered an experiment in which 32 experienced participants (age = 28 ± 7 years, weekly running distance = 51 ± 24 km) ran at a constant speed with modified spatiotemporal gait characteristics (stride length, ground contact time, use of arms). We recorded both their metabolic costs of transportation, as well as running power, as measured by a Stryd sensor. Purposely varying the running style impacts the running economy and leads to significant differences in the metabolic cost of running (p < 0.01). At the same time, the expected rise in running power does not follow this change, and there is a significant difference in the relation between metabolic cost and power (p < 0.001). These results stand in contrast to the previously reported link between metabolic and mechanical running characteristics estimated by foot-worn sensors. This casts doubt on the feasibility of measuring running power in the field, as well as using it as a training signal.

scholarly journals Morphological determinants of jumping performance in the Iberian green frog

2019 ◽  
Vol 66 (4) ◽  
pp. 417-424
Author(s):  
Gregorio Moreno-Rueda ◽  
Abelardo Requena-Blanco ◽  
Francisco J Zamora-Camacho ◽  
Mar Comas ◽  
Guillem Pascual
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Fluctuating Asymmetry ◽  
Hind Limb ◽  
Limb Length ◽  
Age Classes ◽  
Jumping Performance ◽  
Hind Limbs ◽  
Selective Forces ◽  
Pelophylax Perezi

Abstract Predation is one of the main selective forces in nature, frequently selecting potential prey for developing escape strategies. Escape ability is typically influenced by several morphological parameters, such as morphology of the locomotor appendices, muscular capacity, body mass, or fluctuating asymmetry, and may differ between sexes and age classes. In this study, we tested the relationship among these variables and jumping performance in 712 Iberian green frogs Pelophylax perezi from an urban population. The results suggest that the main determinant of jumping capacity was body size (explaining 48% of variance). Larger frogs jumped farther, but jumping performance reached an asymptote for the largest frogs. Once controlled by structural body size, the heaviest frogs jumped shorter distances, suggesting a trade-off between fat storage and jumping performance. Relative hind limb length also determined a small but significant percentage of variance (2.4%) in jumping performance—that is, the longer the hind limbs, the greater the jumping capacity. Juveniles had relatively shorter and less muscular hind limbs than adults (for a given body size), and their jumping performance was poorer. In our study population, the hind limbs of the frogs were very symmetrical, and we found no effect of fluctuating asymmetry on jumping performance. Therefore, our study provides evidence that jumping performance in frogs is not only affected by body size, but also by body mass and hind limb length, and differ between age classes.

scholarly journals Associations Between Foot Placement Asymmetries and Metabolic Cost of Transport in Hemiparetic Gait

2016 ◽  
Vol 31 (2) ◽  
pp. 168-177 ◽  
Author(s):  
James M. Finley ◽  
Amy J. Bastian
Keyword(s):  
Walking Speed ◽  
Metabolic Cost ◽  
Positive Association ◽  
Stroke Survivor ◽  
Gas Analysis ◽  
Stroke Survivors ◽  
Cost Of Transport ◽  
Foot Placement ◽  
Hemiparetic Gait ◽  
All Speeds

Stroke survivors often have a slow, asymmetric walking pattern. They also walk with a higher metabolic cost than healthy, age-matched controls. It is often assumed that spatial-temporal asymmetries contribute to the increased metabolic cost of walking poststroke. However, elucidating this relationship is made challenging because of the interdependence between spatial-temporal asymmetries, walking speed, and metabolic cost. Here, we address these potential confounds by measuring speed-dependent changes in metabolic cost and implementing a recently developed approach to dissociate spatial versus temporal contributions to asymmetry in a sample of stroke survivors. We used expired gas analysis to compute the metabolic cost of transport (CoT) for each participant at 4 different walking speeds: self-selected speed, 80% and 120% of their self-selected speed, and their fastest comfortable speed. We also computed CoT for a sample of age- and gender-matched control participants who walked at the same speeds as their matched stroke survivor. Kinematic data were used to compute the magnitude of a number of variables characterizing spatial-temporal asymmetries. Across all speeds, stroke survivors had a higher CoT than controls. We also found that our sample of stroke survivors did not choose a self-selected speed that minimized CoT, contrary to typical observations in healthy controls. Multiple regression analyses revealed negative associations between speed and CoT and a positive association between asymmetries in foot placement relative to the trunk and CoT. These findings suggest that interventions designed to increase self-selected walking speed and reduce foot-placement asymmetries may be ideal for improving walking economy poststroke.

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