In this comparative study, three transfemoral amputee subjects were fitted with four different microprocessor-controlled exoprosthetic knee joints (MPK): C-Leg, Orion, Plié2.0, and Rel-K. In a motion analysis laboratory, objective gait measures were acquired during level walking at different velocities. Subsequent technical analyses, which involved X-ray computed tomography, identified the func...

In this comparative study, three transfemoral amputee subjects were fitted with four different microprocessor-controlled exoprosthetic knee joints (MPK): C-Leg, Orion, Plié2.0, and Rel-K. In a motion analysis laboratory, objective gait measures were acquired during level walking at different velocities. Subsequent technical analyses, which involved X-ray computed tomography, identified the func...

Physiological studies in walking cats have indicated that two sensory signals are involved in terminating stance in the hind legs: one related to unloading of the leg and the other to hip extension. To study the relative importance of these two signals, we developed a three-dimensional computer simulation of the cat hind legs in which the timing of the swing-to-stance transition was controlled ...

Because the leg is known to exhibit springlike behavior during the stance phase of running, several exoskeletons have attempted to place external springs in parallel with some or all of the leg during stance, but these designs have failed to permit natural kinematics during swing. To this end, a parallel-elastic exoskeleton is presented that introduces a clutch to disengage the parallel leg-spr...

The aims of this study were to investigate the functions of muscle torque and its relation to other torque components during sprinting stance and swing phases. Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters performing maximal-effort sprinting on a synthetic track. Intersegmental dynamics approach (ISD) was used to quantify lower extrem...

In order to solve inverse kinematics of a multi-DOF (degree of freedom) mechanism, many methods have been proposed with the Jacobian linearization method. When solving inverse kinematics problems of the biped robot with this method, long computation time is required since the Jacobian matrix should be updated in order to solve the configuration for each different end-effector trajectory knot. I...

This study investigated the independent effect of added mass on the stability of the leg kinematics during human walking. We reasoned that adding mass would influence the body's inertial state and thus challenge the ability of the leg to redirect and accelerate the total mass of the body while walking. We hypothesized that walking with added mass would reduce the stability of the leg kinematics...

In the course of this thesis, neural mechanisms underlying the generation of single leg stepping in the stick insect Carausius morosus were investigated at the premotor level. Local nonspiking interneurons (NSIs) are important premotor elements within the leg muscle control system of insects, which integrate sensory signals from different sources and provide synaptic drive onto motoneurons (MNs...

The results of applying the Wartenberg pendulum test to the assessment of muscle tone in populations of stroke and Parkinsonian patients are described. The test was able to distinguish between increased muscle tone of the spastic or rigid type. The Parkinsonian patients showed a marked reduction of the maximum velocity of the leg swing, with the relaxation index tending to a value of about one....

This paper modifies the single rigid body (SRB) model, and considers swinging leg as disturbances to centroid acceleration rotational of SRB model. proposes deep reinforcement learning (DRL)-based model predictive control (MPC) resist leg. The DRL predicts swing disturbances, then MPC gives optimal ground reaction forces according predicted disturbances. We use proximal policy optimization (PPO...