Lumbago
Lumbago is a term describing general mid to lower back pain.

What Causes lumbago?
The exact causes of lumbago are unknown or rather its cause could be put down to a variety of things such as lifting objects that are too heavy and not lifting them in a proper way, overuse of the back, or as a result of some other condition you may be suffering from.

A common cause of backache is weak stomach muscles, which increases the stress on the back muscles.

Several factors can contribute to back pain, like a sprain or spasm in a muscle or ligament, compression of the spine, or bulging or ruptured discs, all of which can put pressure on the nerves in the area. Back pain can also result from more serious disorders ranging from a trapped nerve to diabetes and cancer, and although it is often very difficult to determine the exact cause of back pain, some people may develop it for no apparent reason.

What are the Symptoms of Lumbago?
Pain in the lower back that doesn't radiate down through the legs
Stiffness of the back especially in the morning
Poor posture or an "S" shape in the spine.

Lumbago may be accompanied by other symptoms such as:
Loss of sensation in the soles of the feet or in the calf region
Loss of plantar flexion (pointing) of the foot
Back stiffness in other areas of the spine.

Physiotherapy treatment
advise on your posture and exercises to improve it
advice on what you should be avoiding
Thermotherapy
Ultrasound
Massages
Strengthening program; weak stomach muscles are often a cause, regular gentle stomach muscle exercise may make a big difference
Traction or joint manipulation/mobilisation techniques