Differential effects of vestibular stimulation on walking and running

Prompted by our recent observation that an acute vestibular tone imbalance causes less deviation from the intended path when running than when slowly walking, we examined 10 healthy subjects when walking or running at differe nt step frequencies during galvanic vestibular stimulation. Blindfolded sub jects were asked to walk (1 Hz step frequency) or run (3 Hz step frequency) straight ahead toward a previously seen target. The mean gait deviation af ter 10 s was 6.0 +/- 2.4 degrees at 1 Hz and 2.8 +/- 1.8 degrees at 3 Hz st ep frequency (n = 10; P < 0.001, paired t-test). In a second experiment wal king and running in place were investigated. There was no significant diffe rence in body displacement. Walking and running are highly automated proces ses based on spinal locomotor generators that are under supraspinal control . We conclude that vestibular input is differentially regulated depending o n the locomotion speed and pattern used. NeuroReport 11:1745-1748 (C) 2000 Lippincott Williams & Wilkins.