The femoral nerve is located in the leg and supplies the muscles that help straighten the leg. It provides sensation to the front of the thigh and part of the lower leg. Damage to a single nerve group such as the femoral nerve is called mononeuropathy. Mononeuropathy usually means there is a local cause of the nerve damage, although disorders that involve the entire body (systemic disorders) can also cause isolated nerve damage (such as occurs with mononeuritis multiplex). The usual causes of femoral nerve dysfunction are direct trauma, prolonged pressure on the nerve, and compression of the nerve by nearby body structures or disease-related structures (such as a tumor). Prolonged pressure may be complicated by lack of oxygen caused by decreased blood flow (ischemia) in the area. Entrapment involves pressure on the nerve where it passes through a narrow structure (for example, as it passes through a muscle). The damage includes destruction of the myelin sheath of the nerve or destruction of part of the nerve cell (the axon). This damage slows or prevents nerve impulses from passing through the nerve. The femoral nerve can be injured due to pelvic fractures. It can be injured when a catheter is placed in the artery in the groin (femoral artery). It can be affected by diseases causing damage to many nerves (polyneuropathy), such as diabetes. It also can be damaged by pressure from tumors, abscesses, or internal bleeding into the pelvis or abdomen. One common risk factor is lying on the back with the thighs and legs flexed ("lithotomy" position) during surgery or diagnostic procedures. In some cases, no cause can be found. | 
Neuromuscular Disorders (e.g., ALS/Lou Gehrig's Disease)
