Onushko T, Schmit BD. Reflex response to imposed bilateral hip oscillations in human spinal cord injury. J Neurophysiol 98: 1849–1861, 2007. First published July 25, 2007; doi:10.1152/jn.00461.2007. In human spinal cord injury (SCI), imposed unilateral hip movements trigger multijoint, coordinated reflexes that might incorporate interneuronal circuitry involved in normal motor control, such as ...

objectives: although for those spinal cord injury (sci) patients with paralysis of the legs but not at arms, the primary means of mobility post injury is the manual wheelchair, there are many physiological and psychological advantages to standing and walking, such as improvement in respiratory function, lower limb weight bearing and preventing osteoporosis, pressure sores prevention etc. high m...

Broiler (meat) chickens have been subjected to intense genetic selection. In the past 50 years, broiler growth rates have increased by over 300% (from 25 g per day to 100 g per day). There is growing societal concern that many broiler chickens have impaired locomotion or are even unable to walk. Here we present the results of a comprehensive survey of commercial flocks which quantifies the risk...

As an animal moves from air to water, its effective weight is substantially reduced by buoyancy while the fluid-dynamic forces (e. g. lift and drag) are increased 800-fold. The changes in the magnitude of these forces are likely to have substantial consequences for locomotion as well as for resistance to being overturned. We began our investigation of aquatic pedestrian locomotion by quantifyin...

Animals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of a dimensionless parameter (DP) called the Froude number. Consequently, the Froude number has been widely used for defining equivalent speeds and predicting speeds of locomotion by extinct species and on other planets. However, experiments using simulated reduced gra...

Neural control of locomotion in human adults involves the generation of a small set of basic patterned commands directed to the leg muscles. The commands are generated sequentially in time during each step by neural networks located in the spinal cord, called Central Pattern Generators. This review outlines recent advances in understanding how motor commands are expressed at different stages of...

Various robotic quadrupeds have been introduced to investigate the realization of dynamically-stable running behaviors. The majority of these platforms involve rigid, nondeformable torsos, a feature that distinguishes them from their counterparts in the animal world, which owe much of their remarkable locomotion abilities to their flexible bodies. Only a few quadrupedal robots employ torso flex...

In this paper, we report on a new stability analysis for hybrid legged locomotion systems based on factorization of return maps. We apply this analysis to a family of models of the Spring Loaded Inverted Pendulum (SLIP) with different leg recirculation strategies. We obtain a necessary condition for the asymptotic stability of those models, which is formulated as an exact algebraic expression d...

This paper proposes an impedance control method with impedance modulation strategy for biped robot locomotion. Both the constrained leg and the free leg are controlled by impedance control. The impedance parameters changes depending on the gait phase of the biped robot. To reduce the magnitude of an impact and guarantee a stable footing when a foot contacts with the ground, the damping coeffici...

The present paper deals with the motion analysis of the leg tip of a six-legged walking robot, which mimics the kinematic structure and locomotion of the stick insect. The kinematic model of the six-legged walking robot and the appropriate algorithm for the leg coordination were proposed in previous papers to simulate and analyze different types of gait for different speeds of the robot body, b...