Postural Stability in Obese Preoperative Bariatric Patients Using Static and Dynamic Evaluation.

Area of Science:

• Biomechanics
• Human Physiology
• Obesity Research

Background:

• Obesity affects over 300 million adults globally, altering body composition and neuromuscular function.
• Increased adiposity and reduced muscle mass in obesity can compromise postural stability and increase fall risk.
• Previous studies have not specifically isolated the impact of morbid obesity (BMI ≥40 kg/m²) on balance.

Purpose of the Study:

• To investigate the effect of morbid obesity on postural stability.
• To compare postural sway and center of pressure (COP) dynamics in morbidly obese versus nonobese individuals.
• To assess balance control in individuals undergoing bariatric intervention.

Main Methods:

• Assessed 17 morbidly obese subjects (average BMI 40 kg/m²) and 13 nonobese controls (average BMI 30 kg/m²).
• Measured center of pressure (COP) and postural sway using force plate technology during static and dynamic tasks.
• Evaluated balance with eyes open and closed during static stances and voluntary upper torso movements.

Main Results:

• Morbidly obese subjects showed significantly greater anteroposterior (AP) sway displacement (87% eyes open, 76% eyes closed) and higher COP velocity (47% eyes open) during static balance.
• Dynamic tasks revealed no group differences in sway displacement, but obese subjects had reduced mediolateral (ML) COP velocity during AP sway and increased ML COP velocity during ML sway.
• Obese subjects had 85% greater mean body weight compared to nonobese controls.

Conclusions:

• Morbid obesity is associated with significantly increased postural instability, particularly in the AP direction.
• Elevated COP displacement and velocity in obese individuals suggest impaired balance control.
• Understanding these balance deficits can inform targeted physical therapies and post-bariatric surgery rehabilitation.