Measurement of the Hoffmann reflex (H-reflex) provides an estimate of alpha motoneuron activity in the target motoneuron (MN) pool. The H-reflex has been assessed for a wide variety of reasons in neuroscience research. However, the majority of protocols have focused on the assessment of only one muscle and its corresponding motoneuron pool at any instant. Previously established protocols do not...

Our objective was to assess the mechanical changes associated with spasticity in elbow muscles of chronic hemiparetic stroke survivors and to compare these changes with those recorded in the ankle muscles of a similar cohort. We first characterized elbow dynamic stiffness by applying pseudorandom binary positional perturbations to the joints at different initial angles, over the entire range of...

It has been shown that stimulation of cutaneous nerves innervating the hand (superficial radial, SR) and foot (superficial peroneal, SP) elicit widespread reflex responses in many muscles across the body. These interlimb reflex responses were suggested to be functionally relevant to assist in motor coordination between the arms and legs during motor tasks such as walking. The experiments descri...

Modulation of the tibialis anterior (T.A.) H reflex and the reciprocal Ia inhibition from the ankle flexor to the extensor were studied during voluntary teeth-clenching in 7 healthy adult volunteers to investigate the correlation between the oral motor activity and the somatic motor function. The T.A. H reflex was significantly facilitated during voluntary teeth-clenching, and the amount of thi...

We used amplitude modulation of cutaneous reflexes during leg cycling as a paradigm to investigate neural control mechanisms regulating forward (FWD) and backward (BWD) rhythmic limb movement. Our prediction was a simple reversal of reflex modulation during BWD leg cycling and context-dependent reflex modulation. Cutaneous reflexes were evoked by electrical stimulation delivered to the superfic...

BACKGROUND & OBJECTIVES Vibration perception threshold (VPT) is considered as a gold standard for diagnosis of diabetic peripheral neuropathy. However, the data are sparse comparing the VPT with commonly used bedside modalities. This study was carried out to evaluate the usefulness of simple bed side screening modalities for peripheral neuropathy in patients with diabetes mellitus. METHODS A ...

A single-shock stimulus to the skin of widespread and distant parts of the body such as the face, sites in the upper limb, trunk, buttock, and feet produced changes in amplitude of the ankle jerk. A regulated and stabilized system was used for eliciting the ankle jerk and for delivering an unvarying single-shock conditioning stimulus; 35 normal subjects were studied. The characteristics of the ...

Nowadays, objective measures are becoming prominent in spasticity assessment, to overcome limitations of clinical scales. Among others, Tonic Stretch Reflex Threshold (TSRT) showed promising results. Previous studies demonstrated the validity and reliability of TSRT in spasticity assessment at elbow and ankle joints in adults. Purposes of the present study were to assess: (i) the feasibility of...

Background: Several studies have examined the reflex response of ankle musculature to sudden inversion in noninjured and injured subjects. To date, there have been no studies to determine the effect of versatile degrees & conditions of perturbation on the ankle musculature latency. The purpose of this study was to measure and determine whether there was a difference in ankle musculature latency...

INTRODUCTION People with Peripheral Neuropathy (PN), especially those with impaired sensory inputs through the small-afferent fiber (type II afferent fibers) reflex loop (SAF), might depend more on the large-afferent fiber (type I afferent fibers) reflex loop (LAF) for postural control. PURPOSE To examine whether the function of the LAF reflex loop, reflected by the H-reflex and ankle joint p...