Hair stylists and other workers in the service sector perform tasks in uncomfortable positions for extended periods of time, and may repeat the same movements. These tasks can put strain on the body and can result in musculoskeletal injuries (MSIs). MSIs are injuries or disorders of the muscles, tendons, ligaments, joints, nerves, or blood vessels. Some common MSIs include muscle or tendon strains, ligament sprains, and tendonitis. Signs and symptoms of MSIs include redness, swelling, numbness, tingling, stiffness, pain, and difficulty moving a particular body part. Signs and symptoms may appear suddenly, or they may develop over a long period of time. Employers are required to identify risks of MSIs and to control or eliminate them where possible.