@article{oai:niigata-u.repo.nii.ac.jp:00002940,
 author = {Sasagawa, Keisuke and Sakamoto, Makoto and Yoshida, Hidenori and Kobayashi, Koichi and Tanabe, Yuji},
 issue = {Special  Issue},
 journal = {実験力学},
 month = {Sep},
 note = {The wrist is a complex joint, consisting of the eight small carpal bones that articulate with each other, the metacarpals distally, and the radius, ulna, and triangular fibrocartilage complex proximally. The wrist joint carries out complicated motions that combine palmar/dorsal flexion with radio/ulnar deviation. Knowledge of in vivo joint mechanics is important for understanding pathological mechanisms and the treatment of various joint problems. To examine wrist joint contact mechanisms, in vitro cadaveric studies have been performed using pressure-sensitive film. Investigations on in vivo joint contact mechanisms for wrist motion have rarely been reported. The aim of this study is to investigate in vivo wrist joint contact mechanisms during palmar/dorsal flexion by magnetic resonance imaging (MRI). Magnetic Resonance scanning was performed on the left wrist of twelve participants using a 1.5T-MRI system (Achieva, Philips Medical Systems, Best, Netherlands). The wrist joint was scanned at 5 positions (palmar flexion, -30 degree; neutral, 0 degree; and dorsal flexion, 30, 60 and 90 degrees). Quantitative analysis of wrist joint contact mechanisms was performed for 12 normal radioscaphoid and radiolunate joints. The in-plane motions of the scaphoid and lunate were measured. The contact area at the radioscaphoid joint was significantly greater than that at the radiolunate joint in all wrist positions. The contact area increased with increasing wrist angle, and the contact distributions indicated by 3-D models of the scaphoid and lunate were moved during palmar/dorsal flexion. Contributions of the scaphoid and lunate to in-plane motion at 60 degrees of dorsal flexion were 74% and 52%, respectively.},
 pages = {167--171},
 title = {Three-dimensional Contact Analysis of Human Wrist Joint using MRI},
 volume = {9},
 year = {2009}
}