We developed a new evaluation method for the Body Tracking Test (BTT), which evaluates dynamic body balance functions. The evaluation method conventionally used in BTT is called the 5-grade evaluation of tracking ability, in which the score is divided into 5 grades, from A to E. According to this method, the score is based on how frequently movement of the optical target of BTT is in phase with movement of the subject's center of gravity. As this method is marred by the problem of subjective evaluation, we developed a new objective and quantitative evaluation method. We formulated this new evaluation method based on the approach of the 5-grade evaluation of tracking ability.
According to this new evaluation method, evaluation is based on the following steps.
First, define equal-interval widths from the axis of the optical target's movement in the vertical direction as the evaluation widths. Then, draw a straight line parallel to the optical target's movement using the evaluation width, and perform an evaluation based on the number of samples of tracked trajectories that are enclosed by this line.
We also developed a method called the 10-grade evaluation of tracking ability based on such an evaluation method.
The 10-grade evaluations of tracking ability enabled objective and detailed evaluation classifications.