The obturator nerve is a major nerve in the body that originates from the lumbar plexus, specifically from the L2, L3, and L4 spinal nerves. It primarily innervates the muscles of the inner thigh, allowing for movements such as adduction of the leg. This nerve also provides sensory innervation to the skin of the medial thigh. In addition to its motor functions, the obturator nerve plays a role in proprioception, helping the body sense the position of the leg. Injury or compression of this nerve can lead to weakness in leg movements and numbness in the inner thigh area.