Nazarena Mazzaro

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The objective of this study was to determine if load receptors contribute to the afferent-mediated enhancement of ankle extensor muscle activity during the late stance phase of the step cycle. Plantar flexion perturbations were presented in late stance while able-bodied human subjects walked on a treadmill that was declined by 4%, inclined by 4% or held(More)
During the stance phase of the human step cycle, the ankle undergoes a natural dorsiflexion that stretches the soleus muscle. The afferent feedback resulting from this stretch enhances the locomotor drive. In this study a robotic actuator was used to slightly enhance or reduce the natural ankle dorsiflexion, in essence, mimicking the small variations in the(More)
A rapid plantar flexion perturbation applied to the ankle during the stance phase of the step cycle during human walking unloads the ankle extensors and produces a marked decline in the soleus EMG. This demonstrates that sensory activity contributes importantly to the enhancement of the ankle extensor muscle activation during human walking. On average, the(More)
We investigated the contribution of afferent feedback to the soleus (SOL) muscle activity during the stance phase of walking in patients with spastic stroke. A total of 24 patients with hemiparetic spastic stroke and age-matched healthy volunteers participated in the study. A robotic actuator attached to the foot and leg was used to apply 3 types of ankle(More)
The aim of this study was to investigate the contribution of feedback from large-diameter sensory fibers to the adaptation of soleus muscle activity after small ankle trajectory modifications during human walking. Small-amplitude and slow-velocity ankle dorsiflexion enhancements and reductions were applied during the stance phase of the gait cycle to mimic(More)
Walking requires a constant adaptation of locomotor output from sensory afferent feedback mechanisms to ensure efficient and stable gait. We investigated the nature of the sensory afferent feedback contribution to the soleus motoneuronal drive and to the corrective stretch reflex by manipulating body load and ankle joint angle. The volunteers walked on a(More)
The aim of this study was to investigate the contribution of proprioceptive feedback to the amplitude modulation of the soleus muscle activity during human walking. We have previously shown that slow-velocity, small-amplitude ankle dorsiflexion enhancements and reductions applied during the stance phase of the step cycle generate, respectively, increments(More)
39 Walking requires a constant adaptation of locomotor output from sensory afferent 40 feedback mechanisms to ensure efficient and stable gait. We investigated the nature of 41 the sensory afferent feedback contribution to the soleus motoneuronal drive and to the 42 corrective stretch reflex by manipulating body load and ankle joint angle. The 43 volunteers(More)
The objective of the present study was to investigate the involvement of afferent feedback in the generation of plantar flexor muscle activity during human walking. Healthy subjects walked on a treadmill with the left leg attached to a portable stretching device. Changes in the soleus (SOL) background EMG were analyzed following slow, small amplitude,(More)
Currently, most FES assisted walking devices do not incorporate afferent feedback into their control algorithms. During normal human gait, afferent mediated feedback facilitates the extensor EMG activity during the stance phase of the step cycle [e.g. 1, 2, 3]. Recent evidence has suggested that load receptors might contribute importantly in this regard.(More)
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