The lumbar spine is made up of five vertebrae, labeled L1 through L5. The lumbar spine is the lower part of the spine that starts at the bottom of the rib cage and ends at the pelvis. The vertebrae in the lumbar spine are the largest of all the vertebrae and are responsible for supporting much of the body’s weight. The L4-L5 vertebrae are located near the bottom of the lumbar spine and are the most common site for low back pain.
The nerves that are affected by L4-L5 are the femoral nerve, the sciatic nerve, and the obturator nerve. The femoral nerve runs down the thigh, into the knee, and supplies sensation to the front of the thigh, knee, and lower leg. The sciatic nerve is the largest nerve in the body and runs from the lower back down the back of the thigh and into the foot. It supplies sensation to the back of the thigh, lower leg, and foot. The obturator nerve supplies sensation to the inner thigh and knee.
These nerves can be affected by a number of conditions, including lumbar disc herniation, lumbar spinal stenosis, and lumbar facet joint dysfunction. A lumbar disc herniation is when the cushion between two vertebrae (discs) is damaged or ruptured and can cause pressure on the nerves in the area. Lumbar spinal stenosis is a narrowing of the spinal canal, which can also cause pressure on the nerves in the area. Lumbar facet joint dysfunction is when the joints between two vertebrae become restricted and can cause pain and tenderness in the area.
L4-L5 is a common site for low back pain and can be caused by a number of conditions. It is important to seek medical advice if you are experiencing pain in this area. Treatment for lumbar pain and nerve compression can include medications, physical therapy, and in some cases, surgery.