This study analyzed Mann's posture maintenance using motion capture technology.
Subjects participating in this study were healthy people between 20-29 years old (group H, n=12) and patients with unilateral vestibular disorders (group P, n=26). Small reflective markers were placed on the right and left side of the head and shoul-ders. Postural analysis was performed with a video motion analyzer. Two cameras were positioned 4 m behind the subject. The 3-dimensional position of the marker was detected by computer. All subjects were instructed to stand with the right foot in front of the left foot for 30 seconds with eyes closed.
We measured the deviation angle in the roll plane (D-angle) of the head and shoulder using the marker positions. Thereafter, the coefficient of correlation between the pair of angles was calculated. Next, we calculated and compared the degree by measurement of the D-angle's wave area, which was high-pass filtered with 0.12 Hz.
Group H showed various coefficients of correlation in the D-angles in the task, indicating that the strategy for postural control differed among individuals. Group P showed rigidity between the head and shoulder along the D-angle in the task, as esti-mated by the high coefficient of correlation. In group P, the area of the D-angle for both head and shoulder was larger than that of group H. Patients with large D-angle tend toward a larger D-angle at the shoulder than that at the head. On the contrary in patients with a small D-angle and in group H, there were some cases showing a larger D-angle at the head than that at the shoulder.
In this study, we compared the difference in deviation during Mann's posture maintenance between healthy people and patients with unilateral vestibular disorders.
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