Influence of footwear on postural sway: A systematic review and meta-analysis on barefoot and shod bipedal static posturography in patients and healthy subjects.

Background: Bipedal static posturography is widely used to assess postural control. However, standardized methods and evidence on the influence of footwear on balance in comparison to barefoot stance is sparse.

Research Questions: Is bipedal static posturography applied in a standardized way with respect to demographics and the experimental set-up (systematic review)? Does habitual footwear influence postural control in comparison to barefoot condition during bipedal static posturography in adult patients and healthy subjects (meta-analysis)?

Methods: For this systematic review and meta-analysis, a comprehensive follow-up literature search was conducted from March 2009 until January 2020 according to the PRISMA guidelines. Original, research articles reporting on bipedal, unsupported, static posturography in adults (≥18 years) were included according to inclusion criteria (age, sex, height, weight, duration, repetitions, visual/foot condition, sampling frequency). Studies comparing habitual footwear with barefoot condition during bipedal static posturography were included for the meta-analysis. Center of pressure parameters (sway velocity, range, root mean square, paths lengths) with subjects having eyes closed (EC) or open (EO) were analyzed using random effects models.

Results: For this systematic review and meta-analysis, 207 and eight out of 5189 studies with 12'341 and 156 subjects, respectively, were eligible. Most studies (89%) reported barefoot, 5% shod, and 6% barefoot and shod measurements. Less than half of studies (44%) included patients of which the minority (13%) suffered from neurological disease. Sway velocity in the anterior-posterior direction was higher in habitual shoes compared to barefoot with EC (SMD: 1.08; 95% CI: 0.68-1.48; p < 0.01; I = 0%), with EO (SMD: 0.68; 95% CI: 0.11-1.26; p = 0.02; I = 1%), and in the medio-lateral direction with EC (SMD: 1.30; 95% CI: 0.76-1.85, p < 0.01; I = 37%).

Significance: Methodical heterogeneity of bipedal static posturography hampers studies' comparability. Thus, we provide a standardized approach to increase knowledge whether habitual footwear decrease postural control in comparison to barefoot stance.