scholarly journals Rules of nature’s Formula Run: Muscle mechanics during late stance is the key to explaining maximum running speed

Author(s):  
Michael Günther ◽  
Robert Rockenfeller ◽  
Tom Weihmann ◽  
Daniel F. B. Haeufle ◽  
Thomas Götz ◽  
...  

AbstractThe maximum running speed of legged animals is one evident factor for evolutionary selection—for predators and prey. Therefore, it has been studied across the entire size range of animals, from the smallest mites to the largest elephants, and even beyond to extinct dinosaurs. A recent analysis of the relation between animal mass (size) and maximum running speed showed that there seems to be an optimal range of body masses in which the highest terrestrial running speeds occur. However, the conclusion drawn from that analysis—namely, that maximum speed is limited by the fatigue of white muscle fibres in the acceleration of the body mass to some theoretically possible maximum speed—was based on coarse reasoning on metabolic grounds, which neglected important biomechanical factors and basic muscle-metabolic parameters. Here, we propose a generic biomechanical model to investigate the allometry of the maximum speed of legged running. The model incorporates biomechanically important concepts: the ground reaction force being counteracted by air drag, the leg with its gearing of both a muscle into a leg length change and the muscle into the ground reaction force, as well as the maximum muscle contraction velocity, which includes muscle-tendon dynamics, and the muscle inertia—with all of them scaling with body mass. Put together, these concepts’ characteristics and their interactions provide a mechanistic explanation for the allometry of maximum legged running speed. This accompanies the offering of an explanation for the empirically found, overall maximum in speed: In animals bigger than a cheetah or pronghorn, the time that any leg-extending muscle needs to settle, starting from being isometric at about midstance, at the concentric contraction speed required for running at highest speeds becomes too long to be attainable within the time period of a leg moving from midstance to lift-off. Based on our biomechanical model we, thus, suggest considering the overall speed maximum to indicate muscle inertia being functionally significant in animal locomotion. Furthermore, the model renders possible insights into biological design principles such as differences in the leg concept between cats and spiders, and the relevance of multi-leg (mammals: four, insects: six, spiders: eight) body designs and emerging gaits. Moreover, we expose a completely new consideration regarding the muscles’ metabolic energy consumption, both during acceleration to maximum speed and in steady-state locomotion.

1997 ◽  
Vol 200 (16) ◽  
pp. 2189-2195 ◽  
Author(s):  
C T Farley

The goal of the present study was to test the hypothesis that maximum running speed is limited by how much mechanical power the muscular system can produce. To test this hypothesis, two species of lizards, Coleonyx variegatus and Eumeces skiltonianus, sprinted on hills of different slopes. According to the hypothesis, maximum speed should decrease on steeper uphill slopes but mechanical power output at maximum speed should be independent of slope. For level sprinting, the external mechanical power output was determined from force platform data. For uphill sprinting, the mechanical power output was approximated as the power required to lift the center of mass vertically. When the slope increased from level to 40 degrees uphill, maximum speed decreased by 28% in C. variegatus and by 16% in E. skiltonianus. At maximum speed on a 40 degrees uphill slope in both species, the mechanical power required to lift the body vertically was approximately 3.9 times greater than the external mechanical power output at maximum speed on the level. Because total limb mass is small in both species (6-16% of body mass) and stride frequency is similar at maximum speed on all slopes, the internal mechanical power output is likely to be small and similar in magnitude on all slopes. I conclude that the muscular system is capable of producing substantially more power during locomotion than it actually produces during level sprinting. Thus, the capacity of the muscular system to produce power does not limit maximum running speed.


2020 ◽  
Vol 36 (3) ◽  
pp. 134-140
Author(s):  
Piaolin Peng ◽  
Shaolan Ding ◽  
Zhikang Wang ◽  
Yifan Zhang ◽  
Jiahao Pan

The purpose of this study was to explore the immediate effects of running speed and midsole type on foot loading during heel–toe running. Fifteen healthy male college students were required to complete 3 running trials on an indoor 45-m tartan runway at 4 different speeds (3, 4, 5, and 6 m/s) using 2 different running footwear types (engineering thermoplastic polyurethane elastomer, polyurethane elastomer; and ethylene vinyl acetate, vinyl acetate). The ground reaction force and plantar pressure data were quantified. Significant speed effects were detected both in ground reaction force and plantar pressure-related data (P < .05). Vertical average loading rate was significantly less, and time to first peak occurred later for the polyurethane elastomer compared with vinyl acetate footwear (P < .05). The peak pressure of the heel, medial forefoot, central forefoot, lateral forefoot, and big toe was significantly less when subjects wore a polyurethane elastomer than vinyl acetate footwear (P < .05). Overall, our results suggested that, compared with the vinyl acetate footwear, the special polyurethane elastomer footwear that is adhered with thousands of polyurethane elastomer granules was effective at reducing the mechanical impact on the foot.


1992 ◽  
Vol 8 (4) ◽  
pp. 288-304 ◽  
Author(s):  
Martyn R. Shorten ◽  
Darcy S. Winslow

The purpose of this study was to determine the effects of increasing impact shock levels on the spectral characteristics of impact shock and impact shock wave attenuation in the body during treadmill running. Twelve male subjects ran at 2.0, 3.0, 4.0, and 5.0 m s−1on a treadmill. Axial accelerations of the shank and head were measured using low-mass accelerometers. The typical shank acceleration power spectrum contained two major components which corresponded to the active (5–8 Hz) and impact (12–20 Hz) phases of the time-domain ground reaction force. Both the amplitude and frequency of leg shock transients increased with increasing running speed. Greatest attenuation of the shock transmitted to the head occurred in the 15–50 Hz range. Attenuation increased with increasing running speed. Thus transmission of the impact shock wave to the head was limited, despite large increases in impact shock at the lower extremity.


1985 ◽  
Vol 119 (1) ◽  
pp. 71-83 ◽  
Author(s):  
C. L. Johnsrude ◽  
P. W. Webb

Net forces and velocities resulting from in situ contractions of the myotomal musculature on one side of the body were measured at the hypural bones. Forces, velocities and power were determined with the body bent into a range of postures typical of those observed during fast-start swimming. For trout averaging 0.178 m in length and 0.0605 kg in body mass, the muscle system exerts a maximum normal force of 2.2N at the base of the caudal fin. This force is equivalent to 11.8 kN m-2 based on the mean cross-sectional area of the myotomal muscle. The maximum velocity was 1.11 m s-1, and the maximum mechanical power output, 0.64 W, or 42.4 W kg-1 muscle. Based on estimates of swimming resistance, these results would suggest acceleration rates of 7.5 to 16.5 m s-2, similar to averages observed during fast-starts. Maximum sprint speeds would range from 6.5 to 17.8 body lengths s-1, spanning the range of maximum speeds reported in the literature. It is suggested that maximum speed is limited by interactions between muscle contraction frequency and endurance. Losses in the mechanical linkages between muscle fibres and propulsive surfaces were estimated at about 50% for power with possibly greater losses in force transmission. Maximum force and power did not vary over the range of postures tested, supporting Alexander's (1969) suggestions that white muscle should contract over a small portion of the resting length of the fibres.


2018 ◽  
Vol 15 (146) ◽  
pp. 20180276 ◽  
Author(s):  
Christofer J. Clemente ◽  
Nicholas C. Wu

Certain lizards are known to run bipedally. Modelling studies suggest bipedalism in lizards may be a consequence of a caudal shift in the body centre of mass, combined with quick bursts of acceleration, causing a torque moment at the hip lifting the front of the body. However, some lizards appear to run bipedally sooner and for longer than expected from these models, suggesting positive selection for bipedal locomotion. While differences in morphology may contribute to bipedal locomotion, changes in kinematic variables may also contribute to extended bipedal sequences, such as changes to the body orientation, tail lifting and changes to the ground reaction force profile. We examined these mechanisms among eight Australian agamid lizards. Our analysis revealed that angular acceleration of the trunk about the hip, and of the tail about the hip were both important predictors of extended bipedal running, along with increased temporal asymmetry of the ground reaction force profile. These results highlight important dynamic movements during locomotion, which may not only stabilize bipedal strides, but also to de-stabilize quadrupedal strides in agamid lizards, in order to temporarily switch to, and extend a bipedal sequence.


1993 ◽  
Vol 9 (4) ◽  
pp. 306-314 ◽  
Author(s):  
Ewald M. Hennig ◽  
Thomas L. Milani ◽  
Mario A. Lafortune

Ground reaction force data and tibial accelerations from a skin-mounted transducer were collected during rearfoot running at 3.3 m/s across a force platform. Five repetitive trials from 27 subjects in each of 19 different footwear conditions were evaluated. Ground reaction force as well as tibial acceleration parameters were found to be useful for the evaluation of the cushioning properties of different athletic footwear. The good prediction of tibial accelerations by the maximum vertical force rate toward the initial force peak (r2 = .95) suggests that the use of a force platform is sufficient for the estimation of shock-absorbing properties of sport shoes. If an even higher prediction accuracy is required a regression equation with two variables (maximum force rate, median power frequency) may be used (r2 = .97). To evaluate the influence of footwear on the shock traveling through the body, a good prediction of peak tibial accelerations can be achieved from force platform measurements.


2013 ◽  
Vol 19 (4) ◽  
pp. 737-745
Author(s):  
Carlos Gabriel Fábrica ◽  
Paula V. González ◽  
Jefferson Fagundes Loss

Parameters associated with the performance of countermovement jumps were identified from vertical ground reaction force recordings during fatigue and resting conditions. Fourteen variables were defined, dividing the vertical ground reaction force into negative and positive external working times and times in which the vertical ground reaction force values were lower and higher than the participant's body weight. We attempted to explain parameter variations by considering the relationship between the set of contractile and elastic components of the lower limbs. We determined that jumping performance is based on impulsion optimization and not on instantaneous ground reaction force value: the time in which the ground reaction force was lower than the body weight, and negative external work time was lower under fatigue. The results suggest that, during fatigue, there is less contribution from elastic energy and from overall active state. However, the participation of contractile elements could partially compensate for the worsening of jumping performance.


2017 ◽  
Vol 33 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Gaspare Pavei ◽  
Elena Seminati ◽  
Jorge L.L. Storniolo ◽  
Leonardo A. Peyré-Tartaruga

We compared running mechanics parameters determined from ground reaction force (GRF) measurements with estimated forces obtained from double differentiation of kinematic (K) data from motion analysis in a broad spectrum of running speeds (1.94–5.56 m⋅s–1). Data were collected through a force-instrumented treadmill and compared at different sampling frequencies (900 and 300 Hz for GRF, 300 and 100 Hz for K). Vertical force peak, shape, and impulse were similar between K methods and GRF. Contact time, flight time, and vertical stiffness (kvert) obtained from K showed the same trend as GRF with differences < 5%, whereas leg stiffness (kleg) was not correctly computed by kinematics. The results revealed that the main vertical GRF parameters can be computed by the double differentiation of the body center of mass properly calculated by motion analysis. The present model provides an alternative accessible method for determining temporal and kinetic parameters of running without an instrumented treadmill.


2015 ◽  
Vol 49 (4) ◽  
pp. 173-181
Author(s):  
KA Thiagarajan ◽  
Tvisha Parikh ◽  
Anees Sayed ◽  
MB Gnanavel ◽  
S Arumugam

ABSTRACT Cricket fast bowling action involves complex three-dimensional (3D) motion of the body and poses a high risk of injury more so in schoolboys. It is not known how the bowling technique varies between skilled and less skilled fast bowlers. The aim of this study is to compare the differences in bowling technique between young sub-elite (skilled) and amateur university level cricketers. Twelve players, 6 skilled and six amateur, were attached with 35 retro-reflective markers using the full body Plug-in-Gait marker set and asked to bowl 6 deliveries at a good length. Their bowling action was captured with 12 Vicon 3D cameras and the ground reaction force was measured using AMTI force plates. The best delivery from each bowler was selected. Their bowling action types were classified and parameters like shoulder counter rotation (scr), pelvicshoulder separation angle at back foot contact, trunk lateral flexion, front knee angle, front foot vertical ground reaction force (vGRF) and ball release speed were measured. The results were analyzed with Levene's test for Equality of Variances and a t-test for equality of means. The skilled bowlers showed faster ball release speed and experienced larger vGRF while the other parameters did not show any significant differences. How to cite this article Thiagarajan KA, Parikh T, Sayed A, Gnanavel MB, Arumugam S. Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques. J Postgrad Med Edu Res 2015;49(4):173-181.


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