1 Department of Anatomy and Histology, Fukushima Medical University School of Medicine, 1 Hikariga-oka, Fukushima City, Fukushima, 960-1295, Japan.
2 Department of Physical Therapy, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi, Nagoya City, Aichi, 461-8673, Japan.
3 Department of Anatomy and Histology, Fukushima Medical University School of Medicine, 1 Hikariga-oka, Fukushima City, Fukushima, 960-1295, Japan. waguri@fmu.ac.jp.