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 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.

Using body size to understand the structural design of animals: quadrupedal locomotion

1975 ◽  
Vol 39 (4) ◽  
pp. 619-627 ◽  
Author(s):  
T. A. McMahon
Keyword(s):  
Stride Length ◽  
Small Body ◽  
Resting Metabolic Rate ◽  
Theoretical Models ◽  
Stride Frequency ◽  
Maximum Speed ◽  
Published Data ◽  
Body Weights ◽  
And Performance ◽  
Sprinting Speed

Many parameters of gait and performance, including stride frequency, stride length, maximum speed, and rate of O2 uptake are experimentally found to be power-law functions of body weight in running quadrupeds. All of these parameters are reasonably easy to measure except maximum speed, where the question arises whether one means top sprinting speed or top speed for sustained running. Moreover, differences in training and motivation make comparisons of top speed difficult. The problem is circumvented by comparing animals running at the transition between trotting and galloping, a physiologically similar speed. Theoretical models are proposed which preserve either geometric similarity, elastic similarity, or static stress similarity between animals of large and small body weights. The model postulating elastic similarity provides the best correlation with published data on body and bone proportions, body surface area, resting metabolic rate, and basal heart and lung frequencies. It also makes the most successful prediction of stride frequency, stride length, limb excursion angles, and the metabolic power required for running at the trot-gallop transition in quadrupeds ranging in size from mice to horses.

scholarly journals Maximal Sprint Speed in Boys of Increasing Maturity

2015 ◽  
Vol 27 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Robert W. Meyers ◽  
Jonathan L. Oliver ◽  
Michael G. Hughes ◽  
John B. Cronin ◽  
Rhodri S. Lloyd
Keyword(s):  
Contact Time ◽  
Stride Length ◽  
Peak Height ◽  
Flight Time ◽  
Sprint Performance ◽  
Height Velocity ◽  
Stride Frequency ◽  
Peak Height Velocity ◽  
Sprint Speed ◽  
Maximal Speed

The purpose of this study was to examine the natural development of the mechanical features of sprint performance in relation to maturation within a large cohort of boys. Three hundred and thirty-six boys (11-15 years) were analyzed for sprint performance and maturation. Maximal speed, stride length (SL), stride frequency (SF), flight time (FT) and contact time (CT) were assessed during a 30m sprint. Five maturation groups (G1-5) were established based on age from peak height velocity (PHV) where G1=>2.5years pre-PHV, G2 = 2.49-1.5years pre-PHV, G3 = 1.49-0.5years pre-PHV, G4 = 0.49years pre- to 0.5years post-PHV and G5 = 0.51-1.5years post-PHV. There was no difference in maximal speed between G1, G2 and G3 but those in G4 and G5 were significantly faster (p < .05) than G1-3. Significant increases (p < .05) in SL were observed between groups with advancing maturation, except G4 and G5 (p > .05). SF decreased while CT increased (both p < .05) between G1, G2 and G3, but no further significant changes (p > .05) were observed for either variable between G3, G4 and G5. While G1-3 increased their SL, concomitant decreases in SF and increases in CT prevented them from improving maximal speed. Maximal sprint speed appears to develop around and post-PHV as SF and CT begin to stabilize, with increases in maximal sprint speed in maturing boys being underpinned by increasing SL.

scholarly journals Thermal dependence of sprint performance of the lizard Sceloporus occidentalis

1986 ◽  
Vol 126 (1) ◽  
pp. 79-87 ◽  
Author(s):  
R. L. Marsh ◽  
A. F. Bennett
Keyword(s):  
Skeletal Muscle ◽  
Thermal Effects ◽  
Stride Length ◽  
Sprint Performance ◽  
Stride Frequency ◽  
Contraction Time ◽  
Thermal Dependence ◽  
Sceloporus Occidentalis ◽  
Preferred Body Temperature ◽  
Sprint Velocity

Sprint velocity of the lizard Sceloporus occidentalis was maximal at preferred body temperature (Tb, 35 degrees C). Mean running velocity (VR) and stride frequency (f) at this temperature were 3.23 +/− 0.7 (mean +/− S.E.M.) ms-1 and 15.6 +/− 0.3 s-1, respectively. VR and f did not change significantly when Tb was raised to 40 degrees C. At Tb values between 25 and 35 degrees C the thermal dependencies of VR (Q10 = 1.23) and f (Q10 = 1.12) were quite low. At Tb values below 25 degrees C the thermal dependence of these factors increased markedly. Stride length (LS) was independent of Tb from 15 to 40 degrees C. Lizards with a Tb of 10 degrees C were largely incapacitated, and VR, f and LS were all greatly reduced. Comparisons with measurements of the contractile properties of skeletal muscle of this species suggest that stride frequency is limited by the twitch contraction time at temperatures below 23 degrees C. At higher temperatures, sprint performance is nearly independent of the thermal effects on the muscles.

scholarly journals Functional Electrical Stimulation Changes Dynamic Resources in Children With Spastic Cerebral Palsy

2006 ◽  
Vol 86 (7) ◽  
pp. 987-1000 ◽  
Author(s):  
Chia-Ling Ho ◽  
Kenneth G Holt ◽  
Elliot Saltzman ◽  
Robert C Wagenaar
Keyword(s):  
Cerebral Palsy ◽  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Stride Length ◽  
The Body ◽  
Stride Frequency ◽  
Spastic Cerebral Palsy ◽  
Significant Difference ◽  
Muscle Complex ◽  
Spring System

Abstract Background and Purpose. Children with cerebral palsy (CP) often are faced with difficulty in walking. The purpose of this experiment was to determine the effects of functional electrical stimulation (FES) applied to the gastrocnemius-soleus muscle complex on the ability to produce appropriately timed force and reduce stiffness (elastic property of the body) and on stride length and stride frequency during walking. Subjects and Methods. Thirteen children with spastic CP (including 4 children who were dropped from the study due to their inability to cooperate) and 6 children who were developing typically participated in the study. A crossover study design was implemented. The children with spastic CP were randomly assigned to either a group that received FES for 15 trials followed by no FES for 15 trials or a group that received no FES for 15 trials followed by FES for 15 trials. The children who were having typical development walked without FES. Kinematic data were collected for the children with CP in each walking condition and for the children who were developing typically. Impulse (force-producing ability) and stiffness were estimated from an escapement-driven pendulum and spring system model of human walking. Stride length and stride frequency also were measured. To compare between walking conditions and between the children with CP and the children who were developing typically, dimensional analysis and speed normalization procedures were used. Results. Nonparametric statistics showed that there was no significant difference between the children with CP in the no-FES condition and the children who were developing typically on speed-normalized dimensionless impulse. In contrast, the children with CP in the FES condition had a significantly higher median value than the children who were developing typically. The FES significantly increased speed-normalized dimensionless impulse from 10.02 to 16.32 when comparing walking conditions for the children with CP. No significant differences were found between walking conditions for stiffness, stride length, and stride frequency. Discussion and Conclusion. The results suggest that FES is effective in increasing impulse during walking but not in decreasing stiffness. The effect on increasing impulse does not result in more typical spatiotemporal gait parameters. [Ho CL, Holt KG, Saltzman E, Wagenaar RC. Functional electrical stimulation changes dynamic resources in children with spastic cerebral palsy. Phys Ther. 2006;86:987–1000.]

scholarly journals Supervised Exercise Training Improves 6 min Walking Distance and Modifies Gait Pattern during Pain-Free Walking Condition in Patients with Symptomatic Lower Extremity Peripheral Artery Disease

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7989
Author(s):  
Stefano Lanzi ◽  
Joël Boichat ◽  
Luca Calanca ◽  
Lucia Mazzolai ◽  
Davide Malatesta
Keyword(s):  
Stride Length ◽  
Gait Pattern ◽  
Walking Distance ◽  
Stride Frequency ◽  
Walk Test ◽  
Relative Duration ◽  
Foot Kinematics ◽  
Supervised Exercise ◽  
Artery Disease ◽  
Kinematics Parameters

This study aimed to investigate the effects of supervised exercise training (SET) on spatiotemporal gait and foot kinematics parameters in patients with symptomatic lower extremity peripheral artery disease (PAD) during a 6 min walk test. Symptomatic patients with chronic PAD (Fontaine stage II) following a 3 month SET program were included. Prior to and following SET, a 6 min walk test was performed to assess the 6 min walking distance (6MWD) of each patient. During this test, spatiotemporal gait and foot kinematics parameters were assessed during pain-free and painful walking conditions. Twenty-nine patients with PAD (65.4 ± 9.9 years.) were included. The 6MWD was significantly increased following SET (+10%; p ≤ 0.001). The walking speed (+8%) and stride frequency (+5%) were significantly increased after SET (p ≤ 0.026). The stride length was only significantly increased during the pain-free walking condition (+4%, p = 0.001), whereas no significant differences were observed during the condition of painful walking. Similarly, following SET, the relative duration of the loading response increased (+12%), the relative duration of the foot-flat phase decreased (−3%), and the toe-off pitch angle significantly increased (+3%) during the pain-free walking condition alone (p ≤ 0.05). A significant positive correlation was found between changes in the stride length (r = 0.497, p = 0.007) and stride frequency (r = 0.786, p ≤ 0.001) during pain-free walking condition and changes in the 6MWD. A significant negative correlation was found between changes in the foot-flat phase during pain-free walking condition and changes in the 6MWD (r = −0.567, p = 0.002). SET was found to modify the gait pattern of patients with symptomatic PAD, and many of these changes were found to occur during pain-free walking. The improvement in individuals’ functional 6 min walk test was related to changes in their gait pattern.

The use of low doses of acepromazine as an aid for lameness diagnosis in horses: An accelerometric evaluation

2015 ◽  
Vol 28 (05) ◽  
pp. 312-317 ◽  
Author(s):  
Gómez Cisneros ◽  
Varela del Arco ◽  
Santiag Llorente ◽  
Santos González ◽  
F. J. López-Sanromán
Keyword(s):  
Clinical Significance ◽  
Stride Length ◽  
Saline Solution ◽  
Gait Pattern ◽  
Stride Frequency ◽  
Low Doses ◽  
Baseline Values ◽  
Different Doses

Summary Objectives: The aim of the present study was to quantify by accelerometry the trotting pattern of adult horses sedated with two different doses of acepromazine, in order to assess the use of this drug in equine lameness evaluations. Methods: Seven mature horses were used and three treatments were administered to each horse: saline solution, acepromazine (0.01 mg/kg), and acepromazine (0.02 mg/ kg). The portable gait analyzer used consisted of three orthogonal accelerometers that measure accelerations along the dorso -ventral, longitudinal, and lateral axes. Baseline values were obtained and after treatment, accelerometric recordings were repeated every five minutes during the first 20 minutes after the injection and then every 10 minutes thereafter for two hours. Ground-tolip distance was also measured. Results: Administration of acepromazine decreased some of the variables investigated and differences between doses were observed. Speed, stride frequency, and stride length were significantly reduced following treatments. For coordination parameters, no significant differences among values were observed. Energetic variables suffered only weak reductions whereas ground-to-lip distance values were significantly decreased up to 120 minutes after treatment. Clinical significance: Acepromazine produces significant alterations in the gait pattern with differences between doses, but it does not affect coordination variables in normal unexcited horses, and at a dose of 0.01 mg/kg may be the tranquilizer of choice for evaluating lameness in this setting.

scholarly journals Capacitive resistive electric transfer modifies gait pattern in horses exercised on a treadmill

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Mireya Becero ◽  
Aritz Saitua ◽  
David Argüelles ◽  
Antonia Lucía Sánchez de Medina ◽  
Cristina Castejón-Riber ◽  
...  
Keyword(s):  
Stride Length ◽  
Treadmill Exercise ◽  
Gait Pattern ◽  
Sport Performance ◽  
Stride Frequency ◽  
Total Power ◽  
Sham Procedure ◽  
Hemoglobin Saturation ◽  
Pectoral Region ◽  
Deep Temperature

Abstract Background Capacitive resistive electric transfer (CRET), a radiofrequency at 448 kHz, resulted in increased superficial and deep temperature and hemoglobin saturation, faster elimination of metabolic and inflammatory products and enhanced sport performance in humans. This research aims to investigate whether the application of CRET affects the locomotor pattern in horses and to assess whether an accumulative effect appears when two CRET sessions are applied two consecutive days. Methods Nine horses were subjected to two CRET sessions applied in both right and left sides of neck, shoulder, back and croup. The horses were exercised on a treadmill, at walk and at trot, before CRET application and at 2, 6 and 12 h after. A second CRET session was applied next day, and the animals were evaluated again at the same times (i.e. at 26, 30 and 36 h after the first session). Between 5 and 7 days later, the same horses were subjected to a sham procedure and they were evaluated in the same times as in the CRET experiment. During treadmill exercise, locomotor parameters were measured with a triaxial accelerometer fixed in the pectoral region and in the sacrum midline. Results The sham procedure did not affect any of the accelerometric variables studied. CRET applications resulted in greater total powers, which resulted in absolute increased dorsoventral, mediolateral and longitudinal powers. However, a reduction in dorsoventral power expressed as a percentage of total power was found. Stride regularity increased. The greater total power resulted in longer stride length and because the velocity was kept fixed on the treadmill, stride frequency decreased. An accumulative effect of CRET application was only found in stride length and frequency. Conclusions It appears that CRET is a useful technique to enhance power and to elongate the stride at defined walk and trot velocities. The effect of these changes on performance should be studied for horses competing in different sport disciplines.

scholarly journals To slide or stride: when should Adélie penguins (Pygoscelis adeliae) toboggan?

1991 ◽  
Vol 69 (1) ◽  
pp. 221-225 ◽  
Author(s):  
Rory P. Wilson ◽  
Boris Culik ◽  
Dieter Adelung ◽  
N. Ruben Coria ◽  
Hugo J. Spairani
Keyword(s):  
Energy Expenditure ◽  
Stride Length ◽  
Stride Frequency ◽  
Pygoscelis Adeliae ◽  
Additional Energy ◽  
High Incidence ◽  
The Coefficient Of Friction ◽  
Almost All ◽  
Leg Movements ◽  
Adélie Penguins

We noted whether Adélie penguins (Pygoscelis adeliae), when travelling over snow, walked or tobogganed according to gradient, snow friction, or snow penetrability. Both walking and tobogganing penguins reduced stride length and stride frequency, and thus speed, with increasing uphill gradient although tobogganing birds travelled faster and with fewer leg movements. The incidence of tobogganing increased with decreasing friction between penguin and snow. The percentage of penguins tobogganing was also highly positively correlated with increasing snow penetrability. Penguins walking on soft snow must expend additional energy to pull their feet through the snow, whereas tobogganing birds do not sink. It is to be expected that Adélie penguins would utilize the most energetically favourable form of travel which, under almost all conditions, appeared to be tobogganing. Although tobogganing appears to be energetically more efficient than walking, rubbing the feathers over snow increases the coefficient of friction in unpreeened plumage. We propose that a high incidence of tobogganing necessitates increased feather care and that the decision whether to walk or toboggan probably represents a balance between immediate energy expenditure and subsequent energy and time expended maintaining plumage condition.

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