The Evaluation of Tracking Ability by the Body Tracking Test (BTT)

• Published in: Equilibrium Research Vol. 56; no. 1; pp. 39 - 44
• Main Authors: Oda, Makoto, Miyaji, Mamiko, Osafune, Hirotaka, Yamamoto, Masahiko, Yoshida, Tomoe
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Society for Equilibrium Research 1997
• Subjects: Body Tracking Test (BTT); Dynamic postural control; the evaluation of tracking ability
• ISSN: 0385-5716; 1882-577X
• DOI: 10.3757/jser.56.39

To evaluate dynamic postural control, the Body Tracking Test (BTT) was developed. This paper evaluated tracking ability in normal subjects. In this test, the subject standing on the stabilometer was asked to track a moving optical target displayed on the screen by changing his/her bodily position. Stabilometric data of his/her body movement was recorded and computer-analyzed. The horizontal and vertical span of the target was 15 cm on a 14-inch color display monitor. The optical target moved in a horizontal or vertical manner. The movement of the optical target was programmed by controlled triangular waves and the optical speed was 0.125 Hz. The sampling time was 50 mseconds for a total of 60 seconds. In BTT, the gain for target and tracking was 2.0. Healthy young adult volunteers were tested. The age range was 21 to 37 years. There were 87 subjects tested (Male 49, Female 38). The mean age was 27.6. Total distance of bodily movements was adjusted by body weight. The ratio of the total distance of bodily movements divided by total target movement was called "Index of BTT movement". The index of BTT movement was 1.40±0.3 on the average, but the index of BTT movement was not appropriate for evaluating tracking. We were able to extract classifications from the data, which were called "5 grades of evaluating tracking ability". Grades A to E were defined as 30% Grade A, 43.7% Grade B, 21.3% Grade C, 5% Grade D, and 0% Grade E. This evaluation was subjective method, but appropriate for evaluating BTT.