The impact examination of the head tilt size on the subjective visual vertical (SVV) among the normal individuals with ages ranged from 18 to 35 years

Abstract

Objective: The subjective visual vertical (SVV) is commonly considered as an indicator of the sense of orientation. The present study aims to assess the impact of head tilt size (by 0°, 15°, 30° and 45° to the left or to the right) on SVV among the normal individuals with ages ranged from 18 to 35 years.

Methods: Four healthy participants (30 males and 17 females; mean ± SD age: 22.14 ± 3.463) were included in current study. SVV was measured using a forced-choice paradigm and was applied (in different head tilt positions) for every individual twice the time. In addition, difference in averages of SVV in zero and non-zero positions was compared. A p-value of .05 or below was considered to be statistically significant.

Results: There is statistically significant different between head tilt size by 15° and without head tilt for averages of SVV responses (p ˂ .001). Averages of SVV responses were not different between the head tilt size by 30° and 45° and without head tilt (p > .05). In addition, there is statistically significant different between head tilt size by 15° to the left and to the right (p ˂ .001). This rate was not statistically significant between 30° to the left and to the right and 40° to the left and to the right (p > .05).

Conclusion: Our results showed that head tilt size by 15° have an impact on the evaluation of the SVV. These findings must be taken into account in the growing body of research that uses the SVV paradigm in disease settings.

Keywords:

• Angle of head tilt size
• subjective visual vertical
• normal individuals

Acknowledgment

This study is part of the master’s thesis that has been approved and accepted at the University of Social Welfare and Rehabilitation Sciences. All participants in this study are appreciated for participating in the study and their cooperation in the present study.

Disclosure statement

No potential conflict of interest was reported by the author(s).