Sciatica often presents as pain or altered sensation running down the back of the leg, which may or may not be accompanied by back pain. It is caused by the irritation of the sciatic nerve which originates in the lower back and runs down into the legs. This irritation can stem from the joints in the low back, disc or muscle tightness. Sciatica in itself is not a diagnoses. The symptoms can vary from a mild tightening sensation in the hamstring to a constant shooting pain down the back of the leg. Posture often plays a major role in the development of the condition. Sitting for long periods with a bent or flexed lumbar spine leads to an increase in pressure on the discs in the low back, which in turn can result in sciatic symptoms.
