Both the deep and the superficial flexor tendon (DDFT, SDFT) are supported by an accessory  ligament. The accessory ligament of the DDFT is also known as the carpal or inferior check ligament, it originates from the palmar aspects of the carpus and joins the tendon in the middle of the metacarpus. The accessory ligament of the SDFT is also known as the radial or superior check ligament, it originates from the medio-distal aspect of the radius and joins the tendon just above the level of the carpal joint.