The ultrasonographic assessment of the morphologic changes in the ulnar nerve at the cubital tunnel in Japanese volunteers: relationship between dynamic ulnar nerve instability and... oleh Fumitaka Endo, MD, Tsuyoshi Tajika, MD, PhD, Takuro Kuboi, MD, Satoshi Shinagawa, MD, PhD, Toshiki Tsukui, MD, Tomoki Nakajima, MD, Yusuke Kogure, MD, Hirotaka Chikuda, MD, PhD