Class

Article

College

Emma Eccles Jones College of Education and Human Services

Faculty Mentor

Chris Dakin

Presentation Type

Poster Presentation

Abstract

Stair negotiation accounts for 16% of fall related traumatic spinal cord injuries. The vestibular system plays a crucial role in maintaining balance during human locomotion through its influence over muscles in the lower limb, however, its role during stair negotiation is unknown. The aim of this study is to compare the vestibular contribution to a) stair negotiation versus locomotion and b) stair ascent to stair descent in healthy young participants. We hypothesize that vestibular influence will increase during stair negotiation when compared to locomotion. We also expect the timing of muscle responses to change due to differences in gait patterns. To probe the vestibular system, we used a random bandwidth limited white noise stimulus and recorded EMG signals from muscles of the lower leg, upper leg, and hip. Participants completed 304 steps on the treadmill at a cadence of 76 steps/min and a velocity of 0.4 m/s. Participants also ascended and descended an 8-step staircase for a total of 304 steps at a cadence of 76 steps/min. We observed an increase in phase-dependent modulation of vestibular influence during stair negotiation in most muscles except the gluteus medius, which showed a decrease. For all muscles except the soleus, vestibular influence was stronger during stair ascent than stair descent. The phase-dependent timing of vestibular influence for each muscle across the three conditions was also observed. The soleus, medial gastrocnemius, anterior tibialis, biceps femoris, and gluteus medius all showed similar timing of vestibular influence. However, the semimembranosus, rectus femoris, and vastus medialis showed different timing across the three conditions. This suggests a stronger vestibular influence over muscles required for medio-lateral balance versus muscles primarily used in the sagittal plane. These findings also suggest that the phase- and muscle-specific influence of vestibular signals may be stronger during stair negotiation than locomotion.

Location

The North Atrium

Start Date

4-12-2018 9:00 AM

End Date

4-12-2018 10:15 AM

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Apr 12th, 9:00 AM Apr 12th, 10:15 AM

The Vestibular Influence on Balance Control During Stair Negotiation Vs. Locomotion

The North Atrium

Stair negotiation accounts for 16% of fall related traumatic spinal cord injuries. The vestibular system plays a crucial role in maintaining balance during human locomotion through its influence over muscles in the lower limb, however, its role during stair negotiation is unknown. The aim of this study is to compare the vestibular contribution to a) stair negotiation versus locomotion and b) stair ascent to stair descent in healthy young participants. We hypothesize that vestibular influence will increase during stair negotiation when compared to locomotion. We also expect the timing of muscle responses to change due to differences in gait patterns. To probe the vestibular system, we used a random bandwidth limited white noise stimulus and recorded EMG signals from muscles of the lower leg, upper leg, and hip. Participants completed 304 steps on the treadmill at a cadence of 76 steps/min and a velocity of 0.4 m/s. Participants also ascended and descended an 8-step staircase for a total of 304 steps at a cadence of 76 steps/min. We observed an increase in phase-dependent modulation of vestibular influence during stair negotiation in most muscles except the gluteus medius, which showed a decrease. For all muscles except the soleus, vestibular influence was stronger during stair ascent than stair descent. The phase-dependent timing of vestibular influence for each muscle across the three conditions was also observed. The soleus, medial gastrocnemius, anterior tibialis, biceps femoris, and gluteus medius all showed similar timing of vestibular influence. However, the semimembranosus, rectus femoris, and vastus medialis showed different timing across the three conditions. This suggests a stronger vestibular influence over muscles required for medio-lateral balance versus muscles primarily used in the sagittal plane. These findings also suggest that the phase- and muscle-specific influence of vestibular signals may be stronger during stair negotiation than locomotion.