It is of interest to observe that though the femoral nerve supplies the muscles on the front of the thigh, its three roots arise behind the three roots of the obturator nerve, which supplies the muscles on the medial aspect of the thigh. The explanation is that during development the limb undergoes medial rotation whereby the femoral nerve region, from being behind, is brought to the front; and the obturator nerve region is carried from the front to the medial side. The femoral nerve may be compared to a posterior division of the brachial plexus; the obturator nerve to an anterior.
Surgical Anatomy. Arch Surg. 1997;132(1):57. doi:10.1001/archsurg.1997.01430250059013