College of Massage Therapists of British Columbia (CMTBC) Practice Exam

What is the primary function of the obturator nerve?

1. Motor control of the diaphragm

2. Cutaneous sensation of the inner thigh

3. Motor control of the quadriceps

4. Sensation to the hip joint

The correct answer is: Cutaneous sensation of the inner thigh

The primary function of the obturator nerve is to provide motor innervation to the muscles of the inner thigh, particularly the adductor group, as well as to carry sensory information from this region. Although the obturator nerve also contributes to sensory perception, its most notable role is in facilitating the movement of the adductors, which are crucial for actions such as bringing the legs together and stabilizing the pelvis during activities. This makes the answer focused on cutaneous sensation of the inner thigh accurate, as it captures the nerve's role in sensation. However, it’s essential to note that while the sensation to the inner thigh is significant, the motor control aspect of the adductor muscles is equally crucial, as it demonstrates the nerve's active involvement in both motor and sensory pathways. The other options mention functions carried out by other nerves or do not fully relate to the primary role of the obturator nerve, highlighting its specialized nature in the lumbar plexus distribution.