Carpal Kinematics During Active Motion Of The Normal Wrist

Objective:To measure kinematics of all carpal bones in wrist active motion of flexion,extention,ulnar deviation and radial deviation in vivo.Methods:We studied 7 healthy adult volunteers'dominance wrists with CT sca-nning. Each wrist was studied in neutral position,and in the four extreme acti-ve positions:flexion, extension, ulnar and radial deviations.Obtain every carpal bone's images of volume rendering model and images of multi planar reformat model by using CT workstation.We measured carpal bones angular referred to distal radius in.neutral position, and take it to be the standard.Then measured the angular displacements in frontal and sagittal views of every carpal bone in the different positions of the wrist. By comparing the angle values and the volume rendering model images of these wrists to analys carpal bones'kinema-tic.Results:In the wrist extreme active motion of flexion:the scaphoid flexion is 4 6.9°±5.8°,ulnar deviation is 9.3°±5.9°;the lunate flexion is39.4°±4.0°,ulnar deviation is 6.3°±4.5°;the triquetrum flexion is 42.7°±3.4°,ulnar deviation is 8.0°±3.0°;the pisiform flexion is 52.4°±6.6°,radial deviation is 2.1°±3.2°;the trapez-ium, flexion is.70.3°±9.1°,ulnar deviation is 9.0°±3.6°;the trapezoid flexion is.71. 3°±7.0°,ulnar deviation is 3.0°±2.9°;the capitate flexion is.73.7°±4.0°,ulnar devia-tion is 5.4°±3.9°;the'hamate flexion is 72.7°±7.8°,ulnar deviation is 4.7°±2.0°. In the wrist extreme active motion of extention:the scaphoid extension is 54.1°±5.8°,ulnar deviation is 7.6°±2.4°;the lunate extension is 27.7°±5.2°,ulnar deviat-ion is 7.0°±3.4°;the triquetrum extension is 44.2°±5.1°,radial deviation is 7.4°±3.2°;the pisiform extension is 44.7°±5.9°,radial deviation is 7.9°±1.9°;the trapezi-um extension is 57.1°±8.5°,ulnar deviation is14.6°±5.0°;the trapezoid extension is.68.4°±7.0°,radial deviation is 7.9°±5.4°; the capitate extension is 62.9°±7.7°, radial deviationis 9.4°±3.8°;the hamate extension is.41.7°±4.7°,radial deviation is 9.3°±4.1°.And every carpal bone had some rotation changes.In the wrist extre-me active motion of radial deviation:the scaphoid radial deviation is 12.1°±1.9°, flexion is 13.9°±3.1°;the lunate radial deviation is 10.0°±1.6°,flexion is 12.3°±2. 3°;the triquetrum radial deviation is 19.1°±4.1°,flexion is 3.4°±2.4°;the pisiform radial devia-tion is 13.7°±3.9°,extension is 6.4°±3.0°;the trapezium radial devia-tion is 8.7°±3.9°,extension is.12.9°±4.8°;the trapezoid radial deviation is 9.7°±2. 3°,extension is 11.0°±4.5°;the capitate radial deviation is 7.6°±2.7°,extension is 2.9°±1.6°;the hamate radial deviation is 8.0°±2.3°,extension is.1.7°±1. 5°.In the wrist extreme active motion of ulnar deviation:the scaphoid ulnar deviation is 12.7°±3.1°,extension is 24.1°±5.0°;the lunate ulnar deviation is 12.6°±2.5°,extension is 19.7°±3.6°;the triquetrum ulnar deviation is 17.0°±3.7°, extension is 8.3°±2.6°;the pisiform ulnar deviation is 5.0°±3.4°,flexion is 6.3°±3.3°;the trapezium ulnar deviation is 29.6°±6.3°,fle-xion is 25.0°±5.1°;the trapezoid ulnar deviation is 26.4°±8.1°,flexion is 28.1°±7.0°;the capitate ulnar deviation is 19.0°±4.1°flexion is19.4°±5. 2°;the hamate ulnar deviation is 24.4°±3.9°,flexion is 23.6°±5.9°.And there are opposite rotation between distal row and proximal row.Conclusions:carpal bones kinematics is complicated during wrist motion.During wrist flexion and extention,motion of the proximal row carpal bones is signifi-cantly different,and the distal row is not significantly,so can regard it as a rig-id body.During wrist ulnar and radial deviation,motion of the distal row and proximal row is opposite rotation.