Musculoskeletal pain is a common ailment. Muscle, shoulder and leg discomfort are associated with a variety of conditions that range from the most benign, such as muscle overuse and inflammation, to morbidities like polymyalgias, systemic lupus erythematous and vascular abnormalities, notes the book, "Cleveland Clinic: Current Clinical Medicine."
Painful muscles are associated with a variety of conditions, the most common being overactivity, according to "Cecil Medicine." Muscle pain is perceived as radiating from deep within the muscle fibers, giving rise to a diffuse tissue pain. "Neurology in Clinical Practice" notes that symptoms of muscle discomfort include throbbing, fatigue, spasms, cramps, burning and soreness. Chronic pain is widespread and associated with autonomic symptoms. Acute pain is more localized and generally classified as cramping pain, associated with muscle contractions.
"Textbook of Family Medicine" indicates that shoulder pain can come from the muscles of the shoulder girdle, nerves, and the shoulder joint. Shoulder girdle pain is a diffuse aching pain, while nerve pain is sharp and burning. Shoulder joint pain is characterized by discomfort upon movement sometimes associated with clicking or grinding within the joint.
According to "Campbell's Operative Orthopaedics," leg pain is generally associated with nerve, muscle and joint problems. Similar to the pain associated with the shoulder, the most common leg pain is muscular. "Harrison's Principles of Internal Medicine" also includes pain from vascular disorders. For instance, pain associated with arterial disease is characterized by constant dull aching that is worse upon exercise but is relieved by rest and hanging the leg over the edge of a bed.