The impact of wrist laxity on the three-dimensional motion of the triquetrum

The helical axes of motion for the proximal carpal bones were calculated using three-dimensional carpal position data from 10 subjects with varying degrees of wrist laxity. During mid-range wrist ulnar deviation, the triquetrum ulnar-deviated as the scaphoid and lunate extended. We found that with decreasing laxity, the triquetrum undergoes more radial-ulnar deviation during wrist radial-ulnar deviation (RUD).