Load-Regulating Mechanisms in Gait and Posture: Comparative Aspects

2000 ◽  
Vol 80 (1) ◽  
pp. 83-133 ◽  
Author(s):  
J. Duysens ◽  
F. Clarac ◽  
H. Cruse
Keyword(s):  
Functional Role ◽  
Stance Phase ◽  
Force Feedback ◽  
Sensory Information ◽  
Specific Load ◽  
Afferent Activity ◽  
Basic Principles ◽  
Load Sensing ◽  
The Central Nervous System

How is load sensed by receptors, and how is this sensory information used to guide locomotion? Many insights in this domain have evolved from comparative studies since it has been realized that basic principles concerning load sensing and regulation can be found in a wide variety of animals, both vertebrate and invertebrate. Feedback about load is not only derived from specific load receptors but also from other types of receptors that previously were thought to have other functions. In the central nervous system of many species, a convergence is found between specific and nonspecific load receptors. Furthermore, feedback from load receptors onto central circuits involved in the generation of rhythmic locomotor output is commonly found. During the stance phase, afferent activity from various load detectors can activate the extensor part in such circuits, thereby providing reinforcing force feedback. At the same time, the flexion is suppressed. The functional role of this arrangement is that activity in antigravity muscles is promoted while the onset of the next flexion is delayed as long as the limb is loaded. This type of reinforcing force feedback is present during gait but absent in the immoble resting animal.

scholarly journals The Role of Ankle Proprioception for Balance Control in relation to Sports Performance and Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jia Han ◽  
Judith Anson ◽  
Gordon Waddington ◽  
Roger Adams ◽  
Yu Liu
Keyword(s):  
Sports Injuries ◽  
Balance Control ◽  
Sensory Information ◽  
Proprioceptive Information ◽  
Central Processing ◽  
Processing Theory ◽  
The Central Nervous System ◽  
Sports And Exercise ◽  
Ankle Proprioception

Balance control improvement is one of the most important goals in sports and exercise. Better balance is strongly positively associated with enhanced athletic performance and negatively associated with lower limb sports injuries. Proprioception plays an essential role in balance control, and ankle proprioception is arguably the most important. This paper reviews ankle proprioception and explores synergies with balance control, specifically in a sporting context. Central processing of ankle proprioceptive information, along with other sensory information, enables integration for balance control. When assessing ankle proprioception, the most generalizable findings arise from methods that are ecologically valid, allow proprioceptive signals to be integrated with general vision in the central nervous system, and reflect the signal-in-noise nature of central processing. Ankle proprioceptive intervention concepts driven by such a central processing theory are further proposed and discussed for the improvement of balance control in sport.

Model Mediated Telemanipulation

2006 ◽  
Author(s):  
Probal Mitra ◽  
Gu¨nter Niemeyer
Keyword(s):  
Force Feedback ◽  
Sensory Information ◽  
Virtual Model ◽  
Basic Principles ◽  
Natural Motion ◽  
New Information ◽  
Remote Environment ◽  
The Stability ◽  
Master Device

A telemanipulation system allows a human user to manipulate a remote environment using a local interface (master robot) to control a remote (slave) robot. In doing so, it is desirable to provide users with appropriate sensory feedback, most often taking the form of visual and force information. In the presence of communication delays, however, a force feedback telemanipulation system must overcome detrimental effects caused by the delay, both on the quality of feedback to the user and the stability of the control system. For large delays, like those experienced in space telerobotics, the user's perceptive abilities are distorted and challenged by the lag between action and response. With this paper, a user-centered approach is proposed which seeks to simultaneously provide stable master-slave interaction as well as a natural user experience, tolerant of large delays. Rather than directly sending sensory information from the slave robot to the user, the goal is to use this information to create a real-time virtual model of the remote environment, which then serves as the user's interface. Maintaining a dynamic, virtual model locally at the master-side, the user is provided with immediate visual and haptic responses to his/her actions through the master device. At the remote site, the slave robot tracks the user's continuous and natural motion commands, while providing new information needed to update the virtual model. This method abstracts the data transmitted between the sites and creates greater delay tolerance. The basic principles of the approach are demonstrated on a simple one-degree of freedom telerobotic system, with a rigid, stationary slave environment.

scholarly journals Dynamic Principles of Gait and Their Clinical Implications

2010 ◽  
Vol 90 (2) ◽  
pp. 157-174 ◽  
Author(s):  
Arthur D. Kuo ◽  
J. Maxwell Donelan
Keyword(s):  
Gait Pattern ◽  
Heel Strike ◽  
Dynamic Walking ◽  
Basic Principles ◽  
Passive Stability ◽  
Inverted Pendulum Model ◽  
Pendulum Model ◽  
The Central Nervous System ◽  
Biomechanical Features

A healthy gait pattern depends on an array of biomechanical features, orchestrated by the central nervous system for economy and stability. Injuries and other pathologies can alter these features and result in substantial gait deficits, often with detrimental consequences for energy expenditure and balance. An understanding of the role of biomechanics in the generation of healthy gait, therefore, can provide insight into these deficits. This article examines the basic principles of gait from the standpoint of dynamic walking, an approach that combines an inverted pendulum model of the stance leg with a pendulum model of the swing leg and its impact with the ground. The heel-strike at the end of each step has dynamic effects that can contribute to a periodic gait and its passive stability. Biomechanics, therefore, can account for much of the gait pattern, with additional motor inputs that are important for improving economy and stability. The dynamic walking approach can predict the consequences of disruptions to normal biomechanics, and the associated observations can help explain some aspects of impaired gait. This article reviews the basic principles of dynamic walking and the associated experimental evidence for healthy gait and then considers how the principles may be applied to clinical gait pathologies.

scholarly journals Central Neurocircuits Regulating Food Intake in Response to Gut Inputs—Preclinical Evidence

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 908
Author(s):  
Kirsteen N. Browning ◽  
Kaitlin E. Carson
Keyword(s):  
Food Intake ◽  
Vagus Nerve ◽  
Sensory Information ◽  
Specific Reference ◽  
Motor Nucleus ◽  
Dorsal Motor Nucleus ◽  
The Central Nervous System ◽  
Complex Integration ◽  
The Many

The regulation of energy balance requires the complex integration of homeostatic and hedonic pathways, but sensory inputs from the gastrointestinal (GI) tract are increasingly recognized as playing critical roles. The stomach and small intestine relay sensory information to the central nervous system (CNS) via the sensory afferent vagus nerve. This vast volume of complex sensory information is received by neurons of the nucleus of the tractus solitarius (NTS) and is integrated with responses to circulating factors as well as descending inputs from the brainstem, midbrain, and forebrain nuclei involved in autonomic regulation. The integrated signal is relayed to the adjacent dorsal motor nucleus of the vagus (DMV), which supplies the motor output response via the efferent vagus nerve to regulate and modulate gastric motility, tone, secretion, and emptying, as well as intestinal motility and transit; the precise coordination of these responses is essential for the control of meal size, meal termination, and nutrient absorption. The interconnectivity of the NTS implies that many other CNS areas are capable of modulating vagal efferent output, emphasized by the many CNS disorders associated with dysregulated GI functions including feeding. This review will summarize the role of major CNS centers to gut-related inputs in the regulation of gastric function with specific reference to the regulation of food intake.

scholarly journals FFAR1/GPR40 Contributes to the Regulation of Striatal Monoamine Releases and Facilitation of Cocaine-Induced Locomotor Activity in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuko Sadamura ◽  
Shanta Thapa ◽  
Ryota Mizunuma ◽  
Yuki Kambe ◽  
Akira Hirasawa ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Locomotor Activity ◽  
Functional Role ◽  
Acute Administration ◽  
Wild Type ◽  
The Central Nervous System ◽  
Free Fatty Acid Receptor ◽  
G Protein Coupled ◽  
Long Chain

The free fatty acid receptor 1 (FFAR1) is suggested to function as a G protein-coupled receptor (GPR40) for medium-to-long-chain free fatty acids. Previous studies on the expression of FFAR1 revealed that the nigrostriatal region is one of the areas which express abundant FFAR1 mRNA/protein in the central nervous system (CNS). However, the role of FFAR1 in the CNS has been still largely unclarified. Here, we examined a possible functional role of FFAR1 in the control of extracellular concentrations of striatal monoamines and cocaine-induced locomotor activity. Microdialysis analysis revealed that the basal level of extracellular dopamine (DA) was significantly elevated, while the basal serotonin (5-HT) level tended to be reduced in the striatum of FFAR1 knockout (−/−) mice. Interestingly, local application of a FFAR1 agonist, GW9508, markedly augmented the striatal 5-HT release in FFAR1 wild-type (+/+) mice, whereas topical application of a FFAR1 antagonist, GW1100, significantly reduced the 5-HT release. However, the enhanced 5-HT release was completely lost in −/− mice. Although acute administration of cocaine enhanced the locomotor activity in both +/+ and −/− mice, the magnitude of the enhancement was significantly reduced in −/− mice. In addition, intraperitoneal injection of GW1100 significantly decreased the cocaine-induced locomotor enhancement. These results suggest that FFAR1 has a facilitatory role in striatal 5-HT release, and the evoked 5-HT release might contribute to enhance cocaine-induced locomotor activity.

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