Hirofumi Matsumoto, Makoto Shiraishi, Ariaki Higashi, Sakae Hino, Mayumi Kaburagi, Heisuke Mizukami, Futaba Maki, Junji Yamauchi, Kenichiro Tanabe, Tomoo Sato, et al. The Forward and Lateral Tilt Angle of the Neck and Trunk Measured by Three-Dimensional Gait and Motion Analysis as a Candidate for a Severity Index in Patients with Parkinson's Disease. Neurology international. 2022. 14. 3. 727-737