A 1-Diopter Vertical Prism Induces a Decrease of Head Rotation: A Pilot Investigation

- The study explores the link between vertical heterophoria (VH) and head rotation in healthy individuals.
- VH is the misalignment of the eyes when binocular vision is interrupted briefly, and it can exist in healthy subjects in a physiological range.
- Clinical studies suggest an association between VH and non-specific chronic pain in the neck and back, as well as qualitative balance control and mobility of peripheral joints and the spine.
- The experiment induced VH in healthy subjects using a 1-diopter vertical prism base down on either the dominant or non-dominant eye.
- Subjects were asked to rotate their head three times to the right, then back to the center, and three times to the left while standing upright.
- Results show that the experimental VH induced a significant decrease in the mean angle of head rotation compared to normal viewing conditions.
- The decrease in head rotation was particularly significant for rotations to the left.
- The study suggests that the prism-induced VH may modify the reference posture and, thereby, affect head rotation.
- Further studies are needed to confirm these effects and extend the findings to other types of dynamic activities.