PROBLEM TO BE SOLVED: To facilitate a procedure by a chiropractor.SOLUTION: A practitioner of chiropractic puts the legs on step boards 81 and 82 of a foot controller 80 and performs an operation of swinging the step boards 81 and 82. When the step board 81 moves in the direction of downward inclining a front part of a swinging shaft, a drive part 71 moves a femoral-area contact part 50L in a direction of spreading an angle &thetas2. When the step board 81 moves in the direction of downward inclining a rear part of the swinging shaft, the drive part 71 moves the femoral-area contact part 50L in a direction of narrowing the angle &thetas2. When the step board 82 moves in the direction of downward inclining a front part of the swinging shaft, a drive part 72 moves a femoral-area contact part 50R in a direction of spreading an angle &thetas3. When the step board 82 moves in the direction of downward inclining the rear part of the swinging shaft, the drive part 72 moves the femoral-area contact part 50R in a direction of narrowing the angle &thetas3.
