The sciatic nerve is located in the buttock behind the hip joint, courses down behind the thigh bone into the back of the knee where it divides into two nerves which continue into the calf (lower leg). The sciatic nerve may be effected anywhere during its travel in the leg.

Possible causes of Sciatic Nerve Problems in the Leg		Nerves mimicking Spine origin sciatica
Trapping the Nerve in the Tissues (Entrapment) Trauma Tumor Infection Ischemia (lack of blood flow) Neuropthy (Nutrition, Diabetes, Alcohol)		Obturator Saphenous Femoral Iliohypogastric Ilioinguinal Lateral femoral cutaneous Sciatic (Piriformis) Sciatic (Thigh and Knee) Peroneal Tibial

Many potential explanations exisit in the leg that might mimick sciatica from the spine.