J Korean Phys Ther.  2023 Oct;35(5):156-161. 10.18857/jkpt.2023.35.5.156.

Difference in the Static Postural Control according to the Subjective Visual Vertical Deviation and Head Orientations

• Lee SS
• Yeo SS

• KMID: 2552691
• DOI: http://doi.org/10.18857/jkpt.2023.35.5.156

Abstract

Purpose
This study examined the effects of subjective visual vertical perception and head orientation on static balance control.
Methods
The subjects were 25 young and healthy adults. The vertical perception was measured using a subjective visual vertical (SVV), and the Center of pressure (COP) parameter was analyzed by continuously measuring the movement of the COP to determine the changes in static postural control. The group was divided based on a deviation of 3° in SVV (11 of SVV≥3°, 14 of SVV<3°) and measured with different head orientations: front, up, down, left, and right in the upright and tandem positions, respectively.
Results
In the upright position, the SVV≥3° group had significantly larger values for all COP parameters (Sway length, Surface, Delta X, Delta Y, and Average speed) compared to the SVV<3° group (p<0.05). In the tandem stance, only the Ellipse Surface value was significantly larger among the COP parameters in the group with SVV≥3° compared to the group with SVV<3°(p<0.05). In contrast, the other COP parameters were not significantly different (p>0.05). The effects of static balance control on the head orientation were not statistically significant (p>0.05), and the interactions between the subjective vertical perception and head orientation were not significant (p>0.05).
Conclusion
These results suggest that pathological deviations in SVV are associated with impaired static balance performance. This study can provide a therapeutic rationale for using visuospatial cognitive feedback training to improve the static balance.

Keyword

Subjective visual vertical (SVV); Head orientation; Static postural control; Center of pressure (COP)