Related Experiment Videos
Modulation of the startle response during human gait
P H Nieuwenhuijzen1, A M Schillings, G P Van Galen
1Departement of Medical Physics and Biophysics, University of Nijmegen, 6525 EZ Nijmegen, The Netherlands.
Journal of Neurophysiology
|July 19, 2000
Summary
Auditory startle reflexes during walking are phase-dependent, influencing muscle activity and gait stability. These startle reactions adapt to the step cycle, enhancing stability without significantly disrupting gait progression.
Area of Science:
- Neuroscience
- Biomechanics
- Human Movement Science
Background:
- Proprioceptive and exteroceptive reflexes are modulated during gait.
- Auditory reflex modulation during gait remains poorly understood.
Purpose of the Study:
- To investigate the phase-dependent modulation of auditory startle reflexes during human gait.
- To understand how startle reactions are integrated into the ongoing gait pattern.
Main Methods:
- Eight healthy subjects walked on a treadmill at 4 km/h.
- Unexpected auditory stimuli were presented at six different phases of the step cycle.
- Electromyographic activity (EMG) of leg muscles and kinematic data (joint angles, gait phases) were recorded.
Main Results:
- Auditory startle reflexes (F1, F2, F3) showed amplitude modulation dependent on the stimulus timing within the gait cycle.
- The tibialis anterior muscle exhibited a transition from facilitation to suppression.
- Gait characteristics, including step length and joint range of motion, were slightly altered to enhance stability.
Conclusions:
- Auditory startle responses are adapted to enhance stability based on the gait phase.
- Modulation patterns persisted despite rapid habituation of the startle response.
- Observed kinematic changes were minimal, allowing for smooth gait progression.