In cat and humans, contact between an obstacle and the dorsum of the foot evokes the stumbling corrective reaction (reflex) that lifts the foot to avoid falling. This reflex can also be evoked by short trains of stimuli to the cutaneous superficial peroneal (SP) nerve in decerebrate cats during the flexion phase of fictive locomotion. Here we examine intracellular events in hindlimb motoneurons...

In cat and man contact between an obstacle and the dorsum of the foot evokes the stumbling correction reaction (reflex) that lifts the foot to avoid falling. This reflex can also be evoked by short trains of stimuli to the cutaneous superficial peroneal (SP) nerve in decerebrate cats during the flexion phase of fictive locomotion. Here we examine intracellular events in hindlimb motoneurons acc...

Ankle clonus is common after spinal cord injury (SCI) and is attributed to loss of supraspinally mediated inhibition of soleus stretch reflexes and maladaptive reorganization of spinal reflex pathways. The maladaptive reorganization underlying ankle clonus is associated with other abnormalities, such as coactivation and reciprocal facilitation of tibialis anterior (TA) and soleus (SOL), which c...

The "Hanger Reflex" is a phenomenon in which a participant involuntarily rotates their head when a wire hanger is attached it, and has also been observed on the wrist and the ankle. Moreover, the force caused by the Hanger Reflex on the wrist is enhanced by adding a vibration stimulus. These phenomena might be potentially useful for the rehabilitation of movement disorders characterized by abno...

A system has been developed which is able to impose a fast ankle rotation during gait. The two-link system consists of a mechanical joint which is strapped to the calf and the foot of the subject. The mechanical joint turns around the anMe joint by means of bowden wires and it is connected to a motor placed next to a treadmill where the subject is walking. By position feedback from the mechanic...

A previous study has demonstrated that the soleus H reflex is facilitated in association with voluntary teeth clenching in proportion with biting force in humans. The present study tried to elucidate the functional significance of this facilitation of the soleus H reflex, by examining 1) whether the facilitation of the H reflex is reciprocal or nonreciprocal between the ankle extensors and flex...

The conduction velocity along the nociceptive flexor reflex afferent nerve fibres was investigated in human subjects. The posterior tibal nerve was stimulated at two sites by single painful electrical shocks of 1.0 ms duration and with adequate intensity and the reflex EMG discharges were recorded from the short head of the biceps femoris muscle. The fastest reflex conduction velocity along the...

INTRODUCTION Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this st...

The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement behavior of high-heeled and barefooted walking in eleven female subjects. The movement variabilit...

Previous studies have demonstrated that plantar cutaneous afferents can adjust motoneuronal excitability, which may contribute significantly to the control of human posture and locomotion. However, the role of plantar cutaneous afferents with respect to their location specificity in modulating the mechanically induced stretch reflex still remains unclear. In the present study, it was hypothesiz...