[A biomechanical analysis of pronation-supination of the forearm using magnetic resonance imaging: dynamic changes of the interosseous membrane of the forearm during pronation-supination].
A magnetic resonance (MR) study was performed using a 0.5 tesla system to investigate the behavior of the interosseous membrane of the forearm during pronation-supination and to evaluate the influence of pronation-supination loading in the neutral position. The right forearm was examined in twenty volunteers at the proximal fourth part, middle part and distal fourth part of the forearm. Slices were examined at maximum pronation, 45 degrees pronation, neutral, 45 degrees supination and at maximum supination. A 0.1 Nm torque in both rotational directions was added in the neutral position. The MR image of the interosseous membrane of the forearm was a thin line with low contrast in the neutral position. The tendinous portion and membranous portions of the interosseous membrane could be differentiated. At maximum pronation and at maximum supination, the interosseous membrane was flexed, caused mainly by the relaxation in the membranous portion. The radius shifted slightly volarly to the ulna at maximum pronation, caused by the incongruity of the distal radioulnar joint. The radius shifted dorsally with pronation loading, and shifted volarly with supination loading. The inelasticity of the membranous portion of the interosseous membrane may be responsible for pronation-supination contracture, while rotational loading may be a cause of the distal radioulnar joint dislocation. These studies suggest that this technique is useful for further in vivo studies of kinesiology.
Nakamura
T
T
Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
Yabe
Y
Y
Horiuchi
Y
Y
D000328:Adult; D001696:Biomechanical Phenomena; D005542:Forearm; D006801:Humans; D008022:Ligaments / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008566:Membranes / Q000033:anatomy & histology; D008875:Middle Aged; D011403:Pronation / Q000502:physiology*; D013484:Supination / Q000502:physiology*