This normally produces a lot of pain. Discs can degenerate or lose their shape and support, or they can bulge or rupture. Muscles can fatigue and weaken, or become inflexible. A weak abdomen cannot help support your back. Obesity puts an additional stress on the back.
Ligaments can be over-stretched and cause the bones to lose their support.
Poor posture, incorrect body mechanics, stress, inactivity or overexertion can lead to back pain. Good posture is necessary to keep the bones, nerves, muscles, ligaments and discs working well together. Good posture while you move at work or at play is called body mechanics. Learning good body mechanics will keep your back moving safely and efficiently. Keeping your muscles toned and exercised is the key to good body mechanics.