title: The proximal and distal position of the radius relative to the ulna through a full range of elbow flexion and forearm rotation.
abstract: The purpose of this study was to measure the position of the radius relative to the ulna through a complete range of elbow flexion and forearm rotation. Twenty cadaveric upper extremities were mounted on a testing jig that allowed simultaneous control of elbow flexion and forearm rotation. The longitudinal position of the radius relative to the ulna was measured using a three-dimensional digitizer at full pronation, mid-pronation (45°), neutral (0°), mid-supination (45°) and full supination at 10°, 30°, 60°, 90° and 120° of elbow flexion. Our results showed that the radius is located distally when in supination and is located more proximally as it is rotated into pronation. The longitudinal position of the radius changes over 9 mm when moving through a complete arc of forearm rotation. The angle of elbow flexion had a secondary effect on the longitudinal position of the radius, causing changes of less than 0.8 mm.
authors.affiliation: Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, CA, and University of California, Irvine, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Quigley
authors.affiliation: Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, CA, and University of California, Irvine, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Robicheaux
authors.affiliation: Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, CA, and University of California, Irvine, USA tqlee@med.va.gov tqlee@uci.edu.
authors.forename: T Q
authors.initials: TQ
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D004551:Elbow Joint / Q000502:physiology*; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011884:Radius / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D014457:Ulna / Q000502:physiology*
keywords: Ulnar variance; biomechanics; distal radial ulnar joint; radius; ulna