The muscles and ligaments in the back can stretch or tear due to excess activity. Symptoms include pain and stiffness in the lower back, as well as muscle spasms. Rest and physical therapy are remedies for these symptoms. The discs in the back are prone to injury. This risk increases with age. The outside of the disc can tear or herniate. A herniated disc, which is also known as a slipped or ruptured disc, occurs when the cartilage surrounding the disc pushes against the spinal cord or nerve roots. The cushion that sits between the spinal vertebrae extends outside its normal position. This can result in compression of the nerve root as it exits from the spinal cord and through the vertebral bones. Disc injury usually occurs suddenly after lifting something or twisting the back. Unlike a back strain, pain from a disc injury usually lasts for more than 72 hours. Sciatica can occur with a herniated disc if the disc presses on the sciatic nerve. The sciatic nerve connects the spine to the legs. As a result, sciatica can cause pain in the legs and feet. This pain usually feels like burning, or pins and needles.