Standing postural stability relies on input
from visual, vestibular, proprioceptive and mechanoreceptive sensors. When the in
formation
from any o
f these sensors is unavailable or disrupted, the central nervous system maintains postural stability by relying more on the contribution
from the reliable sensors, termed sensory re-weighting. Alcohol intoxication is known to a
ffect the integrity o
f the vestibular and visual systems. The aim was to assess how mechanoreceptive sensory in
formation contributed to postural stability at 0.00%(i.e. sober), 0.06%and 0.10%blood alcohol concentration (BAC) in 25 healthy subjects (mean age 25.1 years). The subjects were assessed with eyes closed and eyes open under quiet standing and while standing was perturbed by repeated, random-length, vibratory stimulation o
f the cal
f muscles. Plantar cutaneous mechanoreceptive sensation was assessed
for both receptor types: slowly adapting (tactile sensitivity) and rapidly adapting (vibration perception). The correlation between recorded torque variance and the sensation
from both mechanoreceptor types was calculated.
The recorded stability during alcohol intoxication was significantly influenced by both the tactile sensation and vibration perception of the subjects. Moreover, the study revealed a fluctuating association between the subjects鈥?vibration perception and torque variance during balance perturbations, which was significantly influenced by the level of alcohol intoxication, vision and adaptation. Hence, one's ability to handle balance perturbations under the influence of alcohol is strongly dependent on accurate mechanoreceptive sensation and efficient sensory re-weighting.