The flexor retinaculum is a fibrous band of connective tissue located in the wrist. It serves as a protective sheath that holds the tendons of the flexor muscles in place as they pass from the forearm into the hand. This structure helps maintain the proper alignment of these tendons during movement. In addition to supporting the tendons, the flexor retinaculum also forms the roof of the carpal tunnel, a narrow passageway that contains important structures such as the median nerve and several flexor tendons. This anatomical feature is crucial for hand function and can be involved in conditions like carpal tunnel syndrome.