scholarly journals The quadrupedal walking gait of the olive baboon, Papio anubis: an exploratory study integrating kinematics and EMG

2021 ◽  
Vol 224 (14) ◽  
Author(s):  
François Druelle ◽  
Anthony Supiot ◽  
Silke Meulemans ◽  
Niels Schouteden ◽  
Pablo Molina-Vila ◽  
...  

ABSTRACT Primates exhibit unusual quadrupedal features (e.g. diagonal gaits, compliant walk) compared with other quadrupedal mammals. Their origin and diversification in arboreal habitats have certainly shaped the mechanics of their walking pattern to meet the functional requirements necessary for balance control in unstable and discontinuous environments. In turn, the requirements for mechanical stability probably conflict with mechanical energy exchange. In order to investigate these aspects, we conducted an integrative study on quadrupedal walking in the olive baboon (Papio anubis) at the Primatology station of the CNRS in France. Based on kinematics, we describe the centre of mass mechanics of the normal quadrupedal gait performed on the ground, as well as in different gait and substrate contexts. In addition, we studied the muscular activity of six hindlimb muscles using non-invasive surface probes. Our results show that baboons can rely on an inverted pendulum-like exchange of energy (57% on average, with a maximal observed value of 84%) when walking slowly (<0.9 m s−1) with a tight limb phase (∼55%) on the ground using diagonal sequence gaits. In this context, the muscular activity is similar to that of other quadrupedal mammals, thus reflecting the primary functions of the muscles for limb movement and support. In contrast, walking on a suspended branch generates kinematic and muscular adjustments to ensure better control and to maintain stability. Finally, walking using the lateral sequence gait increases muscular effort and reduces the potential for high recovery rates. The present exploratory study thus supports the assumption that primates are able to make use of an inverted pendulum mechanism on the ground using a diagonal walking gait, yet a different footfall pattern and substrate appear to influence muscular effort and efficiency.

1997 ◽  
Vol 200 (16) ◽  
pp. 2177-2188 ◽  
Author(s):  
C T Farley ◽  
T C Ko

Lizards bend their trunks laterally with each step of locomotion and, as a result, their locomotion appears to be fundamentally different from mammalian locomotion. The goal of the present study was to determine whether lizards use the same two basic gaits as other legged animals or whether they use a mechanically unique gait due to lateral trunk bending. Force platform and kinematic measurements revealed that two species of lizards, Coleonyx variegatus and Eumeces skiltonianus, used two basic gaits similar to mammalian walking and trotting gaits. In both gaits, the kinetic energy fluctuations due to lateral movements of the center of mass were less than 5% of the total external mechanical energy fluctuations. In the walking gait, both species vaulted over their stance limbs like inverted pendulums. The fluctuations in kinetic energy and gravitational potential energy of the center of mass were approximately 180 degrees out of phase. The lizards conserved as much as 51% of the external mechanical energy required for locomotion by the inverted pendulum mechanism. Both species also used a bouncing gait, similar to mammalian trotting, in which the fluctuations in kinetic energy and gravitational potential energy of the center of mass were nearly exactly in phase. The mass-specific external mechanical work required to travel 1 m (1.5 J kg-1) was similar to that for other legged animals. Thus, in spite of marked lateral bending of the trunk, the mechanics of lizard locomotion is similar to the mechanics of locomotion in other legged animals.


1991 ◽  
Vol 20 (6) ◽  
pp. 308-314
Author(s):  
Thomas J. McCarthy ◽  
Jeffrey D. Fortman ◽  
Melinda L. Boice ◽  
Asgerally T. Fazleabas ◽  
Harold G. Verhage

Author(s):  
Rose-Ange Proteau

A number of dental hygienists have developed pathologies that cause them to be absent from work for long periods of time, and making it difficult for them to return to work. Hygienists' work involves extended static muscular effort in the neck and pectoral girdle, combined with recurrent dynamic movements of the wrist and fingers, associated with efforts to remove tartar from the teeth. Over the last two years, a dozen dental hygienists have consulted us for various shoulder, elbow, wrist, hand and finger problems. Changes in methods, instruments, equipment and the environment have allowed hygienists to adopt safer working positions. Reduced muscular activity was confirmed by EMG testing. The use of telescopic pivoting armrests has facilitated the adoption of new working methods by dental hygienists, and also provided needed arm support. A new concept for a pivoting armrest has been developed with round gel elbows-rests.


1999 ◽  
Vol 86 (1) ◽  
pp. 383-390 ◽  
Author(s):  
Timothy M. Griffin ◽  
Neil A. Tolani ◽  
Rodger Kram

Walking humans conserve mechanical and, presumably, metabolic energy with an inverted pendulum-like exchange of gravitational potential energy and horizontal kinetic energy. Walking in simulated reduced gravity involves a relatively high metabolic cost, suggesting that the inverted-pendulum mechanism is disrupted because of a mismatch of potential and kinetic energy. We tested this hypothesis by measuring the fluctuations and exchange of mechanical energy of the center of mass at different combinations of velocity and simulated reduced gravity. Subjects walked with smaller fluctuations in horizontal velocity in lower gravity, such that the ratio of horizontal kinetic to gravitational potential energy fluctuations remained constant over a fourfold change in gravity. The amount of exchange, or percent recovery, at 1.00 m/s was not significantly different at 1.00, 0.75, and 0.50 G (average 64.4%), although it decreased to 48% at 0.25 G. As a result, the amount of work performed on the center of mass does not explain the relatively high metabolic cost of walking in simulated reduced gravity.


2013 ◽  
Vol 278-280 ◽  
pp. 629-632
Author(s):  
Li Peng Yuan ◽  
Amur Al Yahmedi ◽  
Li Ming Yuan

Here, we consider the walking gait patterns. And we presented a hybrid model for a passive 2D walker with knees and point feet. The dynamics of this model were fully derived analytically. We have also proposed virtual coupling control laws. The control strategy is formed by taking into account the features of mechanical energy dissipation and restoration. And we also prove some walking rules maybe true.


2022 ◽  
Vol 11 (1) ◽  
pp. 1-27
Author(s):  
Luis F. C. Figueredo ◽  
Rafael De Castro Aguiar ◽  
Lipeng Chen ◽  
Thomas C. Richards ◽  
Samit Chakrabarty ◽  
...  

This work addresses the problem of planning a robot configuration and grasp to position a shared object during forceful human-robot collaboration, such as a puncturing or a cutting task. Particularly, our goal is to find a robot configuration that positions the jointly manipulated object such that the muscular effort of the human, operating on the same object, is minimized while also ensuring the stability of the interaction for the robot. This raises three challenges. First, we predict the human muscular effort given a human-robot combined kinematic configuration and the interaction forces of a task. To do this, we perform task-space to muscle-space mapping for two different musculoskeletal models of the human arm. Second, we predict the human body kinematic configuration given a robot configuration and the resulting object pose in the workspace. To do this, we assume that the human prefers the body configuration that minimizes the muscular effort. And third, we ensure that, under the forces applied by the human, the robot grasp on the object is stable and the robot joint torques are within limits. Addressing these three challenges, we build a planner that, given a forceful task description, can output the robot grasp on an object and the robot configuration to position the shared object in space. We quantitatively analyze the performance of the planner and the validity of our assumptions. We conduct experiments with human subjects to measure their kinematic configurations, muscular activity, and force output during collaborative puncturing and cutting tasks. The results illustrate the effectiveness of our planner in reducing the human muscular load. For instance, for the puncturing task, our planner is able to reduce muscular load by 69.5\% compared to a user-based selection of object poses.


2022 ◽  
Vol 15 ◽  
Author(s):  
Artur Agaronyan ◽  
Raeyan Syed ◽  
Ryan Kim ◽  
Chao-Hsiung Hsu ◽  
Scott A. Love ◽  
...  

The olive baboon (Papio anubis) is phylogenetically proximal to humans. Investigation into the baboon brain has shed light on the function and organization of the human brain, as well as on the mechanistic insights of neurological disorders such as Alzheimer’s and Parkinson’s. Non-invasive brain imaging, including positron emission tomography (PET) and magnetic resonance imaging (MRI), are the primary outcome measures frequently used in baboon studies. PET functional imaging has long been used to study cerebral metabolic processes, though it lacks clear and reliable anatomical information. In contrast, MRI provides a clear definition of soft tissue with high resolution and contrast to distinguish brain pathology and anatomy, but lacks specific markers of neuroreceptors and/or neurometabolites. There is a need to create a brain atlas that combines the anatomical and functional/neurochemical data independently available from MRI and PET. For this purpose, a three-dimensional atlas of the olive baboon brain was developed to enable multimodal imaging analysis. The atlas was created on a population-representative template encompassing 89 baboon brains. The atlas defines 24 brain regions, including the thalamus, cerebral cortex, putamen, corpus callosum, and insula. The atlas was evaluated with four MRI images and 20 PET images employing the radiotracers for [11C]benzamide, [11C]metergoline, [18F]FAHA, and [11C]rolipram, with and without structural aids like [18F]flurodeoxyglycose images. The atlas-based analysis pipeline includes automated segmentation, registration, quantification of region volume, the volume of distribution, and standardized uptake value. Results showed that, in comparison to PET analysis utilizing the “gold standard” manual quantification by neuroscientists, the performance of the atlas-based analysis was at >80 and >70% agreement for MRI and PET, respectively. The atlas can serve as a foundation for further refinement, and incorporation into a high-throughput workflow of baboon PET and MRI data. The new atlas is freely available on the Figshare online repository (https://doi.org/10.6084/m9.figshare.16663339), and the template images are available from neuroImaging tools & resources collaboratory (NITRC) (https://www.nitrc.org/projects/haiko89/).


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