A sprain of the low back can occur when a sudden, forceful movement injures a ligament which has become stiff or weak through poor conditioning or overuse. These injuries, or sprain and strain, are the most common causes of low back pain. Although you cannot totally halt the progress of these effects, they can be slowed by regular exercise, knowing the proper way to lift and move objects, proper nutrition, and avoidance of smoking. These changes occur to some degree in everyone. When severe, they can cause low back stiffness and pain.
Arthritic bone spurs and inflamed joints can cause nerve irritation and leg pain.
All bones lose bone strength over time and the lumbar vertebrae, particularly in postmenopausal women, can be fractured or compressed from a fall or even from the stress of lifting or everyday activities. The disk is composed of a soft center or nucleus, which, in children and young adults, is jelly-like. The nucleus is surrounded by a tougher outer portion called the anulus. With normal aging, the nucleus begins to resemble the anulus. During middle-age, fissures or cracks may occur in the disk.