Aches and Pains. Osteoarthritis. PrecautionsPain in the bones, joints, muscles, tendons, and ligaments is very common and accounts for a large number of lost working hours. A common cause of bone pain is flu. Other causes, such a a fracture, may have to be ruled out by a doctor. Muscle and joint pain can be the result of a poor working position, inactivity, bad posture, or aging, or may be symptomatic of an underlying emotional problem such as anxiety. Acute pain in the muscles, joints, tendons, and ligaments can be due to an injury that damages the muscle fibers, tendons, and ligaments and causes stiffness, swelling, and loss of movement.