AbstractPresence of accessory muscles in upper or lower extremities is not uncommon. Variations may be in the form of presence of accessory or duplicate muscles or tendons, absence of muscle or tendon. We report a very rare variation, which is not described previously. During routine dissection of cadavers for teaching medical undergraduates at ESIC Medical Vollege, Sanathnagar, we observed an extra small muscle inbetween the first and the second layer of the sole of the left foot, with a small belly arising from intermuscular septa on the medial side of the foot. It was innervated by medial plantar nerve. Muscle belly was running superficial to flexor digitorum longus tendon and flexor digitorum accessorius from medial to lateral side and formed a tendon which was running medial to and in close contact with the tendon of flexor digitorum longus for little toe, to be inserted along with it at the base of distal phalanx of the little toe. The knowledge of these anatomical variations of foot muscle architecture is utmost importance to orthopedic surgeons, radiologist and podiatrist in analysis of foot function, biomechanical modeling of the foot and prosthesis designing. In painful and disabling conditions of foot during differential diagnosis of the presence of accessory muscles of the foot should be kept in mind. On
other hand additional muscle slip can be used as replacement flaps in cases of tendon rupture or dysfunction.