scholarly journals The Independent Effects And Interaction Of Gravitational And Inertial Forces On Gait Transition Speed.

2020 ◽  
Vol 52 (7S) ◽  
pp. 734-734
Author(s):  
Nathan G. Frakes ◽  
Justus D. Ortega ◽  
Courtney A. Perry
Keyword(s):  
Inertial Forces ◽  
Gait Transition ◽  
Transition Speed ◽  
Independent Effects

Pectoral fin locomotion in the striped surfperch. II. Scaling swimming kinematics and performance at a gait transition

1996 ◽  
Vol 199 (10) ◽  
pp. 2243-2252 ◽  
Author(s):  
E Drucker ◽  
J Jensen
Keyword(s):  
Body Size ◽  
Swimming Speed ◽  
Beat Frequency ◽  
Small Fish ◽  
Maximal Velocity ◽  
Pectoral Fin ◽  
Gait Transition ◽  
Transition Speed ◽  
Aspect Ratios ◽  
And Performance

In this study, we report the first allometric equations relating gait parameters and swimming speed to body size for fish employing pectoral fin locomotion. Comparisons of locomotor kinematics and performance among striped surfperch (Teleostei: Embiotocidae) are made at the pectoral­caudal gait transition speed (Up-c). Up-c is considered to elicit physiologically equivalent levels of exercise in animals varying over 100-fold in body mass (Mb) by virtue of dynamically similar pectoral fin movements (constant duty factor, length-specific stride length and fin-beat amplitude) and size-independent propulsive efficiency. At Up-c, pectoral fin-beat frequency scales in proportion to Mb-0.12±0.03, a size-dependence consistent with that observed for stride frequency in fishes swimming by axial undulatory propulsion and in many running tetrapods. It is proposed that the similarity in the scaling of frequency in these vertebrate groups reflects an underlying similarity in the allometry of the maximal velocity of muscle shortening. Absolute Up-c (m s-1) generally increases with body size, but the fastest speeds are not exhibited by the largest animals. A pattern of declining performance in fish 23 cm in standard length and longer may be related to their disproportionately small fin areas and aspect ratios. The pronounced negative allometry of Up-c expressed as standard body lengths per second indicates that a given length-specific speed does not induce comparable levels of activity in large and small fish. Thus, normalization of swimming speed to body length may not be a sufficient correction for kinematic comparisons across size.

Stability Landscapes of Walking and Running Near Gait Transition Speed

2000 ◽  
Vol 16 (4) ◽  
pp. 428-435 ◽  
Author(s):  
Li Li
Keyword(s):  
Systems Approach ◽  
Quantitative Measure ◽  
Human Locomotion ◽  
Human Motion ◽  
Mathematical Representation ◽  
Gait Transition ◽  
Transition Speed ◽  
Acceleration And Deceleration ◽  
Transition Change ◽  
The Stability

Variability has long been used as an indication of stability in the application of a dynamical systems approach to human motion (i.e., greater variability has been related to a less stable system and vise versa). This paper incorporates the probability of gait transition during walking and running at a certain speed to represent the stability of human locomotion. The mathematical representation concerning the probability of gait transition change with locomotory speed was derived for increasing walking speed and decreasing running speed. Additionally, the influence of acceleration and deceleration on the stability landscapes of walking and running was discussed based on experimental data. The influence of acceleration was also used to explain the different trends of hysteresis observed by various researchers. Walk-to-run transition speed was greater than run-to-walk transition speed, with a greater magnitude of acceleration, while the trend was reversed with a lesser acceleration magnitude. The quantitative measure of the relationship between variability and stability needs to be explored in the future.

An Electromyographical Analysis of the Role of Dorsiflexors on the Gait Transition during Human Locomotion

2001 ◽  
Vol 17 (4) ◽  
pp. 287-296 ◽  
Author(s):  
Alan Hreljac ◽  
Alan Arata ◽  
Reed Ferber ◽  
John A. Mercer ◽  
Brandi S. Row
Keyword(s):  
Tibialis Anterior ◽  
Walking Speed ◽  
Vastus Lateralis ◽  
Human Locomotion ◽  
Medial Gastrocnemius ◽  
Energetic Cost ◽  
Emg Activity ◽  
Gait Transition ◽  
Transition Speed ◽  
Preferred Transition Speed

Previous research has demonstrated that the preferred transition speed during human locomotion is the speed at which critical levels of ankle angular velocity and acceleration (in the dorsiflexor direction) are reached, leading to the hypothesis that gait transition occurs to alleviate muscular stress on the dorsiflexors. Furthermore, it has been shown that the metabolic cost of running at the preferred transition speed is greater than that of walking at that speed. This increase in energetic cost at gait transition has been hypothesized to occur due to a greater demand being placed on the larger muscles of the lower extremity when gait changes from a walk to a run. This hypothesis was tested by monitoring electromyographic (EMG) activity of the tibialis anterior, medial gastrocnemius, vastus lateralis, biceps femoris, and gluteus maximus while participants (6 M, 3 F) walked at speeds of 70, 80, 90, and 100% of their preferred transition speed, and ran at their preferred transition speed. The EMG activity of the tibialis anterior increased as walking speed increased, then decreased when gait changed to a run at the preferred transition speed. Concurrently, the EMG activity of all other muscles that were monitored increased with increasing walking speed, and at a greater rate when gait changed to a run at the preferred transition speed. The results of this study supported the hypothesis presented.

What factors determine the preferred gait transition speed in humans? A review of the triggering mechanisms

2018 ◽  
Vol 57 ◽  
pp. 1-12 ◽  
Author(s):  
Stacey M. Kung ◽  
Philip W. Fink ◽  
Stephen J. Legg ◽  
Ajmol Ali ◽  
Sarah P. Shultz
Keyword(s):  
Gait Transition ◽  
Transition Speed ◽  
Triggering Mechanisms

Energy Comparison Between Trot, Bound, and Gallop Using a Simple Model

1995 ◽  
Vol 117 (4) ◽  
pp. 466-473 ◽  
Author(s):  
P. Nanua ◽  
K. J. Waldron
Keyword(s):  
Simple Model ◽  
Periodic Solutions ◽  
Energy Levels ◽  
The Body ◽  
Experimental Results ◽  
Gait Transition ◽  
Transition Speed ◽  
Quadruped Trot

In this paper, the dynamics of quadruped trot, gallop, and bound will be examined using a simple model for the quadruped. The body of the quadruped is modeled as a uniform bar and the legs are modeled by massless springs. It will be shown that symmetry can be used to study the locomotion of this system. Using symmetry, a technique will be developed to obtain periodic solutions for each of the gaits of the quadruped model. These periodic solutions will be computed at various speeds. The energy levels will be compared for each of the gaits. The exchange of energy between its different forms will be shown for different gaits. It will be shown that even without body flexibility, there are significant savings in energy due to gait transition from trot to gallop. The energy levels will be used to predict the trot-gallop transition speed. These results will be compared with the experimental results for horses and dogs.

Changes in the Preferred Transition Speed With Added Mass to the Foot

2014 ◽  
Vol 30 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Toran D. MacLeod ◽  
Alan Hreljac ◽  
Rodney Imamura
Keyword(s):  
Angular Velocity ◽  
Critical Level ◽  
Angular Acceleration ◽  
Gait Transition ◽  
Joint Power ◽  
Transition Speed ◽  
Dependent Variables ◽  
Incremental Protocol ◽  
Preferred Transition Speed ◽  
Male Subjects

This study was conducted to investigate whether adding mass to subjects’ feet affects the preferred transition speed (PTS), and to ascertain whether selected swing phase variables (maximum ankle dorsiflexion angular velocity, angular acceleration, joint moment, and joint power) are determinants of the PTS, based upon four previously established criteria. After the PTS of 24 healthy active male subjects was found, using an incremental protocol in loaded (2 kg mass added to each shoe) and unloaded (shoes only) conditions, subjects walked at three speeds (60%, 80%, and 100% of PTS) and ran at one speed (100% of PTS) on a motor-driven treadmill while relevant data were collected. The PTS of the unloaded condition (2.03 ± 0.12 m/s) was significantly greater (P< .05) than the PTS of the loaded condition (1.94 ± 0.13 m/s). Within both load conditions, all dependent variables increased significantly with walking speed, decreased significantly when gait changed to a run, and were assumed to provide the necessary input to signal a gait transition, fulfilling the requirements of the first three criteria, but only ankle angular velocity reached a critical level before the transition, satisfying all four criteria to be considered a determinant of the PTS.

Sign in / Sign up

Export Citation Format

Share Document