Biomechanical Properties of the Transverse Carpal Ligament Under Biaxial Strain

This study provided the first biaxial mechanical characterization of the transverse carpal ligament (TCL), the structure forming the volar boundary of the carpal tunnel. Eight cadaver arms were dissected, and six samples per ligament were tested to map regional variations in material properties. Results demonstrated significant regional heterogeneity in thickness and modulus: proximal segments were consistently thicker, and the elastic modulus was greatest at the proximal radial location. Stress–strain profiles showed a long toe region typical of collagen uncrimping followed by linear stiffening. The TCL is anisotropic and location-dependent, with increased stiffness near bony attachments contributing to carpal tunnel boundary mechanics.