Myalgia (also called muscle pain and muscle ache in laymans terms) is the medical term for muscle pain. Myalgia is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, especially when there has been no trauma. Long-lasting myalgia can be caused by metabolic myopathy, some nutritional deficiencies, and chronic fatigue syndrome. Causes
The most common causes of myalgia are overuse, injury, and strain. Myalgia might also be caused by allergies, diseases, medications, or as a response to a vaccination. Dehydration at times results in muscle pain as well, especially for people involved in extensive physical activities such as workout. Muscle pain is also a common symptom in a variety of diseases, including infectious diseases, such as influenza, muscle abscesses, Lyme disease, malaria, trichinosis or poliomyelitis; autoimmune diseases, such as celiac disease, systemic lupus erythematosus, Sjögrens syndrome or polymyositis; gastrointestinal diseases, such as non-celiac gluten sensitivity (which can also occur without digestive symptoms) and inflammatory bowel disease (including Crohns disease and ulcerative colitis).The most common causes are:

Overuse
Overuse of a muscle is using it too much, too soon or too often. One example is repetitive strain injury. See also:

Exercise
Weight lifting

Injury
The most common causes of myalgia by injury are: sprains and strains.
Saber shin is a malformation of the tibia. It presents as a sharp anterior bowing, or convexity, of the tibia. Causes
Periosteal reaction along the shaft of the tibia. It can result from congenital syphilis, yaws, Pagets disease of bone, vitamin D deficiency or Weismann-Netter–Stuhl syndrome. It can be due to osteomalacia. Prognosis
Etymology
Saber refers to the tibias resemblance to the curve of a saber sword. See also
Saddle nose
List of cutaneous conditions
Rickets

References
Bibliography
Mosbys Medical, Nursing, & Allied Health Dictionary. Edition 5, 1998 p7B49.