backache may be due to twisting, sudden jolts, and daily stresses (such as sitting too much, poor posture). Common causes of back pain include:large nerve roots that go to the legs and arms may be irritated The smaller nerves in the discs may be irritated The large paired back muscles that support the spine may be strained Any of the bones, ligaments, or joints throughout the spine may be injured. bruise or discoloration of skin may be due to Muscle strain Muscle strain occurs when muscles are stressed, overworked, or injured due to physical activity or labor. Hematoma A hematoma is a collection of blood in the tissue outside of a damaged blood vessel, usually after an injury. it will subside it self within 5 to 10 days. you should keep posture straight,avoid straining,intake proper iron calcium diet.avoid forward movement to keep backache away.