A 42-year-old male reports pain in his lower back for the past month. The pain sometimes radiates to his left leg. In determining the cause of the back pain, based on your knowledge of anatomy, what nerve roots might be involved

The sciatic nerve is the longest and thickest in the anatomy and it originates from the sacral plexus. The sciatic nerve and its nerve branches allow movement and sensation (motor and sensory functions) in the thigh, knee, calf, ankle, feet, and fingers. When the pain exceeds the lumbar area and reaches the lower limbs, we speak of radiating lumbar pain. If the pain spreads from the lower back to the heel or foot, down the back or side of the thigh, we call it lumbosciatica (or just sciatica). Its presence suggests injury to the nerve roots that come out of the lumbar spine and carry the sensation or orders to contract the muscles to the lower limbs through the sciatic nerve.