Acute alcohol intoxication impairs segmental body alignment in upright standing

Area of Science:

• Biomechanics
• Neuroscience
• Human Physiology

Background:

• Balance control is a complex process involving coordination, feedback, feedforward control, and adaptation.
• Acute alcohol intoxication is a major cause of falls requiring medical attention.

Purpose of the Study:

• To investigate the effects of alcohol intoxication on body alignment during upright stance.
• To quantify changes in head, shoulder, hip, and knee alignment at blood alcohol concentrations of 0.06% and 0.10%.

Main Methods:

• 3D-motion analysis was used to measure angular positions of body segments in 25 healthy adults.
• Participants stood with or without perturbations and with eyes open or closed.
• Measurements were compared between sober and intoxicated states.

Main Results:

• Alcohol intoxication significantly altered body alignment in both perturbed and unperturbed stances.
• Intoxication induced more posterior knee and shoulder alignment and a tendency for more posterior/leftward head alignment during perturbations.
• The most significant impact was on knee alignment, with impaired adaptation to perturbations when visual information was limited.

Conclusions:

• Acute alcohol intoxication leads to inadequate balance control strategies, characterized by increased postural rigidity.
• Impaired adaptation to perturbations contributes to the elevated risk of falling when intoxicated.
• Alcohol significantly affects body alignment, compromising overall postural stability.