What is a stress fracture like?

Comprehensive analysis of stress fracture

Generally, fractures often occur in intense antagonistic sports. The fracture in running is different from the general fracture, which is usually caused by the cumulative effect of the ground. This kind of fracture is also called stress fracture.

Tibia is the most prone to fracture during running, followed by phalanx, fibula, femur, ankle and pubis.

Before a stress fracture occurs, runners usually feel local pain, which is not serious when they rest and walk, but it will get worse when they start running, which is usually the most important index for diagnosing stress fractures. There are also some inspection methods to judge whether there is the possibility of stress fracture:

1, a certain part (usually in the lower limbs) has not been violently collided by the outside world and suddenly there is pain, which makes it impossible for people to continue running, or it is difficult to continue running.

2, local pain when standing on one foot, or pain when jumping on one foot.

3. It hurts when you press it with your fingers.

4. After stopping running completely, the pain point will disappear naturally within a period of time.

Generally, fractures often occur in intense antagonistic sports. The fracture in running is different from the general fracture, which is usually caused by the cumulative effect of the ground. This kind of fracture is also called stress fracture.

Tibia is the most prone to fracture during running, followed by phalanx, fibula, femur, ankle and pubis.

Stress fracture is a fracture caused by the collapse of mechanical strength of bone. The collapse factors are: ① continuous, long-term or repeated stress acts on the stressed bone; ② Strength of the bone itself. The common stress fractures of the foot are the second metatarsal, calcaneus, talus, fibula and scaphoid. Calcaneus is common in children, while talus and fibula can be produced in both adults and children. The second metatarsal bone is more common in athletes and recruits, especially female recruits (about 25% of recruits).

The trauma history of fatigue fracture may be vague. Pain after exercise is relieved after rest. Pain after compression of diseased bone. The examination showed local swelling and tenderness. X-ray showed that the fracture line was not clear in the early stage, but clear in the later stage, with callus formation.

Treatment is mainly local rest, weight-free exercise or plaster fixation.

Progressive fracture is the most common foot fatigue fracture. Most common in the second metatarsal shaft, followed by the third metatarsal bone. Biomechanical studies in recent years have found that the walking load of each metatarsal of the foot decreases from the first metatarsal to the fifth metatarsal (Ⅰ 26%, Ⅱ 20.2%, Ⅲ11.8%, Ⅳ 7.6%, Ⅴ 5.5%). The weight-bearing value of the second metatarsal is larger than the other three lateral metatarsal weight-bearing areas, second only to the first metatarsal, but the area of the second metatarsal weight-bearing area is half that of the first metatarsal. In this way, the pressure (pressure/area) of the second metatarsal region is greater than that of the first metatarsal. However, the cortical bone of the first metatarsal shaft is thicker, and there is a strong attachment of the medial foot muscle. The cross section at the narrowest part of the metatarsal shaft is twice that of the second metatarsal shaft, so the pressure on the second metatarsal shaft is also greater than that on the first metatarsal shaft. This is enough to explain the most common cause of fatigue fracture of the second metatarsal shaft.

The cause of fatigue fracture of scaphoid is also related to stress concentration. Biomechanical research in recent years has proved that the fully loaded tripod structure is wrong. According to biomechanics, the load when standing is 83% of the body weight, which is the main load-bearing part. The navicular bone is the apex of the medial longitudinal arch, which bears the greatest stress, so it is more prone to fatigue fracture than other tarsal bones.