The muscles, bursae, tendons, and bones must be healthy and functioning correctly for the body to move normally. Muscles, which contract to produce movement, are connected to the bones by tendons. Bursae are flat sacs containing joint (synovial) fluid. They reduce friction in areas where skin, muscles, tendons, and ligaments rub over bones. (See also Biology of the Musculoskeletal System Introduction to the Biology of the Musculoskeletal System The musculoskeletal system provides form, stability, and movement to the human body. It consists of the body's bones (which make up the skeleton), muscles, tendons, ligaments, joints, cartilage... read more .)
Often, muscles, bursae, and tendons are injured during sports activities Overview of Sports Injuries Sports injuries are common among athletes and other people who participate in sports. Certain injuries that are traditionally considered sports injuries can also occur in people who do not participate... read more 
. Injury, overuse, infection, and occasionally disease can temporarily or permanently damage these structures. Damage can cause pain, limit control over movement, and reduce the normal range of motion.
Disorders of the muscles, bursae, and tendons include
Fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more , although covered here, is thought to be a central pain syndrome, not a disorder of muscles, bursae, or tendons.
