Are cutaneous reflexes from the foot preserved in passive walking in a DGO?

Driven Gait Orthosis (DGO) are commonly used in gait rehabilitation. These devices commonly lack an actuator at the ankle. As a result the ankle trajectories often differ considerably from those seen normally.

Dynamic posturography in Parkinson's disease: diagnostic utility of the "first trial effect".

Previous dynamic posturography studies demonstrated clear abnormalities in balance responses in Parkinson's disease (PD) patients compared to controls at the group level, but its clinical value in the diagnostic process and fall risk estimation in individual patients leaves for improvement. Therefore, we investigated whether a new approach, focusing on the balance responses to the very first and fully unpractised trial rather than a pooled mean response to a series of balance perturbations, could further improve the diagnostic utility of dynamic posturography. Following the first trial, subjects were exposed to repeated balance perturbations, which also permitted us to investigate the training responses.

How trunk turns affect locomotion when you are not looking where you go.

How well do we maintain heading direction during walking while we look at objects beside our path by rotating our eyes, head, or trunk? Common experience indicates that it may be fairly hazardous not to look where you are going. In the present study, 12 young adults walked on a treadmill while they followed a moving dot along a horizontal line with their gaze by rotating primarily either their eyes, head, or trunk for amplitudes of up to 25 degrees . During walking the movement of the center of pressure (COP) was monitored using force transducers under a treadmill.

Suppression of cutaneous reflexes by a conditioning pulse during human walking.

There are two ways in which responses to successive unexpected stimuli are attenuated, namely through habituation and conditioning. For the latter, it suffices that the unexpected stimulus is preceded by another just perceivable stimulus. In spinal cord reflexes this is termed conditioning, while in brainstem reflexes this is usually referred to as prepulse inhibition.

Cutaneous reflexes evoked during human walking are reduced when self-induced.

Reflex responses are often less pronounced when they are self-induced, but this question has barely been investigated quantitatively. The issue is particularly relevant for locomotion since it has been shown that reflexes elicited during normal gait are important for the regulation of locomotion. The cortex is thought to be involved in the control of reflexes during gait, but it is unclear whether it plays a role in the modulation of these reflexes during the step cycle.

Gait acts as a gate for reflexes from the foot.

During human gait, electrical stimulation of the foot elicits facilitatory P2 (medium latency) responses in TA (tibialis anterior) at the onset of the swing phase, while the same stimuli cause suppressive responses at the end of swing phase, along with facilitatory responses in antagonists. This phenomenon is called phase-dependent reflex reversal. The suppressive responses can be evoked from a variety of skin sites in the leg and from stimulation of some muscles such as rectus femoris (RF).

Neuronal coordination of arm and leg movements during human locomotion.

We aimed to study the neuronal coordination of lower and upper limb muscles. We therefore evaluated the effect of small leg displacements during gait on leg and arm muscle electromyographic (EMG) activity in walking humans. During walking on a split-belt treadmill (velocity 3.

Arm to leg coordination in humans during walking, creeping and swimming activities.

In walking humans, arm to leg coordination is a well established phenomenon. The origin of this coordination, however, remains a matter for debate. It could derive from the intrinsic organisation of the human CNS, but it could also consist of a movement induced epiphenomenon.

Reflex adaptations during treadmill walking with increased body load.

Load dependent reflex adaptations were studied in healthy subjects walking on a split-belt treadmill. Compensatory reflex responses were elicited in the right leg extensor muscles during mid-stance by a short acceleration of the right treadmill belt. Electromyographic activity (EMG) was recorded from the right medial gastrocnemius (GMR), soleus (SO) and tibialis anterior (TA) muscles of the right leg as well as from the gastrocnemius of the left unperturbed leg (GML).

Modulation of cutaneous reflexes by load receptor input during human walking.

To investigate the influence of load on the modulation of cutaneous reflexes, evoked by sural nerve stimulation, electromyographic activity in different leg muscles (tibialis anterior, gastrocnemius medialis (GM), biceps femoris, and soleus muscles (SO)) was recorded in healthy humans during treadmill walking with different body loads. Sural nerve stimulation was applied at two times perception threshold during different phases of the step cycle. Reflex amplitudes increased with body unloading and decreased with body loading.