Human movement science
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Human movement science · Dec 2018
You are better off running than walking revisited: Does an acute vestibular imbalance affect muscle synergies?
It has been suggested that vestibular cues are inhibited for the benefit of spinal locomotor centres in parallel with the increase in locomotion speed. This study aimed at quantifying the influence of a transient vestibular tone imbalance (TVTI) on gait kinematics, muscle activity and muscle synergies during walking and running. Twelve participants walk or run at a self-selected speed with or without TVTI, which was generated by 10 body rotations just prior the locomotion task. ⋯ Under TVTI, there was an increased gait deviation in walking compared to running (22.8 ± 8.4° and 8.5 ± 3.6°, respectively; p < 0.01), while the number (n = 4) and the composition of the muscle synergies did not differ across conditions (p = 0.78). A higher increase (p < 0.05) in EMG activity due to TVTI was found during walking compared to running, especially during stance. These findings confirmed that the central nervous system inhibited misleading vestibular signals according to the increase in locomotion speed for the benefit of spinal mechanisms, expressed by the muscle synergies.