Exercise

• People who perform intense exercise may injure their muscles. Beginning an exercise session without being in good condition may stress the muscles and ligaments and lead to injuries. People who lift more weight than the muscles can handle may get a type of muscle injury referred to as a strained or pulled muscle.
  
  

Infections

• People who get infected with certain types of bacteria, viruses or parasites may experience muscle injuries as a result of the infection. Parasitic infections such as trichinosis and malaria can cause muscle pain and injury as the parasites develop in the human body. Staphylococcal (staph) bacterial infections can injure and kill muscle tissue, nerves and bone.
  
  

Muscle Disorders

• People with certain types of muscle disorders may develop muscle injuries and damage as a result of their disorder. People with rhabdomyolysis, polymyositis or dermatomyositis may develop muscle damage and injury over the course of the disease. Lupus and fibromyalgia are chronic conditions that may cause pain, dysfunction and injury to muscles.
  
  

Overuse

• People who overuse a muscle may develop a muscle injury. Sports players and other types of athletes may experience muscle injuries during training, practice or physical contact in their sport. People who have physically demanding jobs may overuse certain muscles and develop muscle injuries.
  
  

Poor Technique

• People who use poor or improper technique during physical activity or exercise may injure their muscles. Bending with the back instead of the legs and knees when lifting something can injure the back muscles. People who do not train the muscles before a workout may get muscle injuries.
  
  

Trauma

• People who experience physical trauma may injure their muscles. Auto accidents, falls, assault and domestic violence are types of trauma that can lead to muscle injuries. People who undergo surgery that requires cutting through muscle may develop injuries as a result of trauma from the procedure.