Flatback syndrome
Flatback syndrome refers to loss of lumbar lordosis. Normally, the lumbar spine has a gentle backwards sway of approximately 40 degrees. When lordosis is lost, the lumbar spine straightens. Symptoms include back pain and a forward tilt of the upper back and head. Often patients have to bend the hips and knees in order to stand and look upright (see figure). If severe, the normal lordosis of the lumbar spine can be reversed into abnormal kyphosis.