ABSTRACT
L3 contributes to the innervation of the psoas, adductor, and quadriceps muscles and, with its posterior ramus, the spinal muscles. The L4 root contributes to the innervation of the gluteal, adductor, quadriceps, tibialis anterior, and extensor digitorum and, with its posterior ramus, the spinal muscles. When the quadriceps is involved, the patient cannot raise the heel from the supine position. In a severe attack, the lower limb gives way and causes falls.
