Overexertion can cause injuries to the leg, causing sudden throbbing and persistent pain. Running on hard surfaces or wearing worn-out shoes or the wrong shoes for a particular activity can also cause strains and sprains of the muscles and tendons in the leg. People with an abnormal foot alignment that causes their feet to turn inward and individuals who run on the outside edges of their soles are also susceptible to pain and injury to the leg.
Fracture
A sudden blow to the leg or a serious injury to the ankle may fracture the tibia or fibula. The doctor may apply a cast to such fractures, but sometimes a fracture of this type requires surgery to secure the fragments in place with plates or screws. A stress fracture is the result of repeated stress that causes a small crack in the tibia or fibula. According to the Mayo Clinic, fracture classifications include open, closed, incomplete, complete, displaced, greenstick and comminuted, all of which can cause intense pain in the leg.
Achilles Tendinitis
When the tendon that connects the calf muscle to the heel becomes inflamed, it can be extremely painful. Minor injuries to the Achilles tendon are common. Changing running surfaces, breaking in a new pair of shoes or using shoes that are not suitable for the sport can also cause Achilles tendinitis. Shoes with high counters or heel tabs on the back of the shoe may cause Achilles tendinitis if there is a lot of friction between the counter and the tendon. According to the U.S. National Library of Medicine, Achilles tendinitis is primarily the result of overuse or arthritis but can also result from trauma and infection.
Strains and Sprains
Sudden stretching, stooping or falling can cause a tear within the inner calf muscle. This can also occur by landing awkwardly on the toes and by exercising without an appropriate warm-up. According to the U.S. National Library of Medicine, sprains result from over-stretched or torn ligaments, the tissues that connect bones at the joint, causing pain and swelling as well as bruising. A stretched or torn muscle or tendon, the tissues that connect muscle to bone, can cause a strain.
Shin Splints
Shin splints can cause an arching pain that develops at the front of the leg and may have a number of causes. According to the U.S. National Library of Medicine, a minor tear of a muscle, inflammation of the periosteum--the fibrous covering of the tibia--increased pressure in the anterior tibial compartment of the leg or a stress fracture may cause shin splints.
Compartment Syndrome
This painful condition occurs when an injury causes swelling, bleeding or both within a specific area of the leg. This injury can exert pressure on the capillaries, muscles and nerves, leading to permanent damage without immediate medical attention. According to the American Academy of Orthopaedic Surgeons, acute compartment syndrome can be the result of a fracture, bruising, removal of a cast or tight bandage, a crushing injury and steroid use.
