Yann Thibaudier

• PhD
• PostDoc Position at University of Florida

Background: Returning to community walking remains a major challenge for persons with incomplete spinal cord injury (iSCI) due, in part, to impaired interlimb coordination. Here, we examined spatial and temporal features of interlimb coordination during walking and their associations to gait deficits in persons with chronic iSCI. Research questio...

When the foot contacts an obstacle during locomotion, cutaneous inputs activate spinal circuits to ensure dynamic balance and forward progression. In quadrupeds, this requires coordinated reflex responses between the four limbs. Here, we investigated the patterns and phasic modulation of cutaneous reflexes in forelimb and hindlimb muscles evoked by...

Persons with incomplete spinal cord injury (iSCI) face ongoing struggles with walking, including reduced speed and increased reliance on assistive devices (ADs). The forces underlying body weight support and gait, as measured by ground reaction forces (GRFs), are likely altered following iSCI due to weakness and AD dependence but have not been stud...

Cutaneous reflexes are important for responding rapidly to perturbations, correcting limb trajectory, and strengthening support. During locomotion, they are modulated by phase to generate functionally appropriate responses. The goal of the present study was to determine whether cutaneous reflexes and their phase-dependent modulation are altered wit...

Key points: Coordination between the left and right sides is essential for dynamic stability during locomotion. The immature or neonatal mammalian spinal cord can adjust to differences in speed between the left and right sides during split-belt locomotion by taking more steps on the fast side. We show that the adult mammalian spinal cord can also...

Complete spinal cord injury (SCI) alters the contractile properties of skeletal muscle and although exercise can induce positive changes, it is unclear if the remaining motor system can produce adaptive muscle plasticity in response to a subsequent peripheral nerve injury. To address this, the nerve supplying the lateral gastrocnemius and soleus mu...

Coordination between the arms/forelimbs and legs/hindlimbs is often impaired in humans and quadrupedal mammals after incomplete spinal cord injury. In quadrupeds, the forelimbs often take more steps than the hindlimb, producing a two-to-one forelimb-hindlimb (2-1 FL-HL) coordination. In locomotor performance scales, this is generally considered a l...

When changing speed during locomotion, both temporal and spatial parameters of the pattern must adjust. Moreover, at slow speeds the step-to-step pattern becomes increasingly variable. The objectives of the present study were to assess if the spinal locomotor network adjusts both temporal and spatial parameters from slow to moderate stepping speeds...

Hindlimb (HL) locomotion recovers in chronic spinal‐transected cats following ankle extensors neurectomy (Bouyer et al. 2001), indicating compensatory spinal mechanisms. However, such recovery has only been tested during single‐belt treadmill locomotion at moderate speeds (0.35 m/s to 0.5 m/s). Here, HL locomotion was assessed at several speeds and...

The modulation of the neural output to forelimb and hindlimb muscles when the left and right sides step at different speeds from one another in quadrupeds was assessed by obtaining electromyography (EMG) in seven intact adult cats during split-belt locomotion. To determine if changes in EMG during split-belt locomotion were modulated according to t...

Sensory feedback is a potent modulator of the locomotor pattern generated by spinal networks. The purpose of this study was to assess the effect of cutaneous inputs from the back on the spinal-generated locomotor pattern. The spinal cord of six adult cats was transected at low thoracic levels. Cats were then trained to recover hindlimb locomotion....

Interlimb coordination must be flexible to adjust to an ever-changing environment. Here, adjustments in interlimb coordination were quantified during tied-belt (equal speed of the fore- and hindlimbs) and transverse split-belt (unequal speed of the fore- and hindlimbs) locomotion in five intact adult cats. Cats performed tied-belt locomotion at 0.4...

Stepping along curvilinear paths produces speed differences between the inner and outer limb(s). This can be reproduced experimentally by independently controlling left and right speeds with split-belt locomotion. Here, we provide additional details on the pattern of the four limbs during quadrupedal split-belt locomotion in intact cats. Six cats p...

It is well established that stance duration changes more than swing duration for a given change in cycle duration. Small variations in cycle duration are also observed at any given speed on a step-by-step basis. To evaluate the step-by-step effect of speed on phase variations, we measured the slopes of the linear regressions between the phases (i.e...

Proper coordination of the four limbs, or interlimb coordination, is a fundamental requirement for locomotion in terrestrial mammals. The control of interlimb coordination during quadrupedal locomotion was studied in adult cats by independently controlling the speed of the left and right sides, or of the fore- and hindlimbs, using a treadmill with...

During overground or treadmill walking, the stance phase and cycle durations are reduced as speed increases, whereas swing phase duration remains relatively invariant. When the speed of the left and right sides is unequal, as is the case during split-belt locomotion or when walking along a circular path, adjustments in stance and swing phases are o...

Despite the obvious importance of inter-girdle coordination for quadrupedal locomotion in terrestrial mammals, its organization remains poorly understood. Here, we evaluated cycle and phase durations, as well as footfall patterns of four intact adult cats trained to walk on a transverse split-belt treadmill that could independently control fore- an...

In this study, we used a novel technique to study reflex wind-up when the spinal cord is intact and following an acute spinal transection. Specifically, we evaluated reflex responses evoked by a series of ten electrical pulses to the tibial or superficial peroneal nerves in 9 decerebrate adult cats, before and after an acute spinal transection. Ele...

Propriospinal pathways are thought to be critical for quadrupedal coordination by coupling cervical and lumbar central pattern generators (CPGs). However, the mechanisms involved in relaying information between girdles remain largely unexplored. Using an in vitro spinal cord preparation in neonatal rats, Juvin and colleagues (Juvin et al. 2012) hav...