Flexor digitorum superficialis (FDS) is a muscle which exists on the front side of the forearm. The main tendon of the muscle divides into four tendons. It inserts to both sides of the middle phalanges of fingers 2 to 5. It provides rapid and strong flexion to fingers 2-5. Here we report findings of an unusual variant of FDS in a 78-year-old male cadaver, observed during educational dissection for the medical students. The main tendon of FDS divided into three tendons. The FDS tendon to the little finger was absent. The unusual muscle belly was 4.9 mm in width and 48.8 mm in length. The total length of the tendon was 130 mm. While the first part of 83.5 mm of the tendon from the (width 1.3 mm) was like a slip, its distal part from the metacarpophalangeal joint continued as a thick structure of 4.4 mm. It was crossed at the top of the level of the wrist by the FDS tendon to the 4th finger. The distance between the origin of this variant muscle originating from the belly of FDS for the 2nd and 3rd fingers to the radiocarpal joint was 82.7 mm. The knowledge of such muscle/tendon variantions is highly imperative in the management of compressive neuropathies, because of the close neighborhood of the FDS tendons with the median nerve in the wrist.
