A Case Report on Third Head of Biceps Femoris Muscle

Abstract

Biceps femoris variants, such as an accessory head of biceps femoris, can be seen on sometimes. We identified a case with an accessory head of biceps femoris in both lower limbs during normal cadaveric dissection in the department of anatomy, All India Institute of Medical Sciences, Jodhpur. The muscle belly originates from the fibres of the long head of the biceps femoris and goes downward medially to the medial superior aspect of the tibia's medial condyle. The insertion point on the right side looks like a sheath, and it merges halfway with the medial intermuscular septum of the thigh. The insertion on the left side looks like a thin sheath at first, then a thin muscle belly. In comparison to the long and short heads of the primary muscle bellies, the muscle belly is thin. The thickness on the left side is around 3.7mm on the higher end and thinner on the lower end, while the thickness on the right side is also around 3.75mm.  The length of the muscle belly on the right side is around 5cm, while on the left side it is around 5.5cm. The muscle belly then becomes a sheath with a length of around.5mm, before returning to a length of around 3.5cm.On the left side, a short head appears high above, whereas the right side is normal.