Chiropractors use hands-on spinal manipulation and other alternative treatments, the theory being that proper alignment of the body's musculoskeletal structure, particularly the spine, will enable the body to heal itself without surgery or medication. Manipulation is used to restore mobility to joints restricted by tissue injury caused by a traumatic event, such as falling, or repetitive stress, such as sitting without proper back support. Chiropractic is primarily used as a pain relief alternative for muscles, joints, bones, and connective tissue, such as cartilage, ligaments, and tendons. It is sometimes used in conjunction with conventional medical treatment. The treatment plan may involve one or more manual adjustments in which the doctor manipulates the joints, using a controlled, sudden force to improve range and quality of motion. Many chiropractors also incorporate nutritional counseling and exercise/rehabilitation into the treatment plan. The goals of chiropractic care include the restoration of function and prevention of injury in addition to back pain relief.