Effect of different wrist positions on median nerve cross-sectional area at proximal carpal tunnel

Musculoskeletal disorders such as carpal tunnel syndrome can be caused by repeated, awkward wrist postures during daily work. The objective of this study was to identify the changes of median nerve cross-sectional area at different wrist angles. Twelve right-handed males participated in this study. Ultrasound examinationwas performed on the right wrist.Atotal of seven angles were examined, namely, wrist neutral (0◦), wrist extension 15◦, 30◦, 45◦ and wrist flexion 15◦, 30◦, 45◦. The results showed that the reduction of median nerve cross-sectional area was significant when wrist neutral changed to wrist extension and wrist flexion (p<0.001). Our findings showed that the reduction of median nerve cross-sectional area was greater at wrist extension 45◦ and wrist flexion 45◦ than at wrist neutral and other wrist extension and flexion angles.