[1] Iwate Med Univ, Dept Hyg & Prevent Med, Sch Med, Morioka, Iwate 0208505, Japan
[2] Iwate Med Univ, Dept Med 2, Sch Med, Morioka, Iwate 0208505, Japan
[3] Iwate Med Univ, Dept Neurosurg, Sch Med, Morioka, Iwate 0208505, Japan
[4] Iwate Univ, Fac Educ, Dept Hlth & Phys Educ, Morioka, Iwate, Japan