Morphological and positional changes of the carpal arch and median nerve associated with wrist deviations

Abstract Background Carpal tunnel and median nerve dynamically change with wrist motion. The purpose of this study was to investigate the morphological changes and positional migration of the carpal arch and median nerve, as well as nerve-arch positional relationship associated with wrist deviation in healthy volunteers. Methods Twenty asymptomatic male volunteers performed wrist motion from neutral to deviated positions combining flexion-extension and radioulnar deviation. Ultrasound images of the carpal arch and median nerve at the distal carpal tunnel were collected during wrist motion. Morphological and positional parameters of the carpal arch and median nerve were derived from the ultrasound images. Findings Carpal arch height, area, and palmar bowing of the transverse carpal ligament (TCL) increased with flexion related wrist motion and decreased with extension related motion (P  Interpretation The current study advances our understanding the effect of wrist motion on the carpal tunnel and its contents, which has implications for pathomorphological and pathokinematic changes associated with wrist disorders.