Additional Tendinous Slips of Extensor Carpi Radialis Longus and Brevis of Hand: A Case Study

Two primary muscles of the forearm of extensor group are located on the radial side of the wrist, named as the extensor carpi radialis longus (ECRL) muscle and extensor carpi radialis brevis (ECRB) muscle. At the musculotendinous junction, the ECRL and ECRB travel deep to the abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus muscles and tendons in the hand. The ECRB is covered by the ECRL as it courses distally. An additional tendon slip of the ECRL and from ECRB, respectively, was discovered during dissection of the forearm’s extensor compartment and dorsum of the hand with the cadaver in the supine position. The intermedius tendinous slip from ECRL to ECRB originates from the lateral side of ECRL and gets inserted within the same tendinous sheath of the tendon of ECRB, similarly, tendinous slip from ECRB to ECRL originates from the side of ECRB, cross the intermedius slip of ECRL superficially and gets inserted on the base of second metacarpal bone with the tendon of ECRL.