Terrestrial legged locomotion requires repeated support forces to redirect the body's vertical velocity component from down to up. We assume that the redirection is accomplished by impulsive leg forces that cause small-angle glancing collisions of a point-mass model of the animal. We estimate the energetic costs of these collisions by assuming a metabolic cost proportional to positive muscle wo...

Background During human walking the ankle-foot complex executes seemingly contradictory functions: (1) stabilization of the human body at initial contact, (2) shock absorption during early stance [1-3], (3) Storing elastic energy during midstance and (4) providing a strong lever for push of during final stance [1]. This quadrupled function inevitably demands a transfer from a flexible and compl...

Stresses on the surface of a stump within a prosthetic socket during walking can potentially traumatize stump tissues. To gain insight into stresses and design parameters that affect them, normal and shear interface stresses were measured on three unilateral trans-tibial amputee subjects during walking trials. During stance phase repeated characteristics in wave-form shapes from different subje...

In this paper, we present a theoretical study on the control of a compass gait walker using energy regulation between steps. We use a return map to relate the mid-stance robot kinetic energy between steps with the two control inputs, namely, foot placement and ankle push-o↵. We show that by regulating the robot kinetic energy between steps using the two control inputs, we are able to: 1) genera...

The aim of this study was to investigate how the coordination patterns of shoulder muscles change with level-ground and incline wheelchair propulsion. Wheelchair kinetics and electromyography (EMG) activity of seven muscles were recorded with surface electrodes for 15 nondisabled subjects during wheelchair propulsion on a stationary ergometer and wooden ramp (4 degree slope). Kinetic data were ...

Robust walking under various ground condition is required for application of biped robots. Some researches deal with the biped robot control considering foot slip as [1] and [2]. However, few research deal with recovery control after slip. Our work presents balance recovery trajectory design and disturbance-observer (DOB) based control [3]. Balance recovery trajectory is designed through slip r...

A lateral deviation of the walking trajectory is often observed in stroke patients with unilateral spatial neglect. However, existing research appears to be contradictory regarding the direction of this deviation. The aim of the present study was to gain more insight into the walking trajectory of neglect patients. Twelve right hemisphere stroke patients (six neglect, six no neglect), eight lef...

Application of chondroitinase ABC (ChABC) to injured peripheral nerves improves axon regeneration, but it is not known whether functional recovery is also improved. Recordings of EMG activity [soleus (Sol) M response and H reflexes] evoked by nerve stimulation and of Sol and tibialis anterior (TA) EMG activity and hindlimb and foot kinematics during slope walking were made to determine whether ...

Recovery is experienced in both positive and negative ways this paper attempts to integrate the ‘pains of desistance’ approach into a recovery capital framework. Pains as result are often thought stimulate motivations for behavioral change, usually through ‘rock bottom’ type moment. Whilst barriers have been explored literature, conceptualizing these push pull factors, exploring their dynamic i...