Biomechanical aspects of lumbar spine injuries in athletes: a review.

One of the areas of the body which is very often injured by athletes is the lower lack, or the lumbar area of the spine. This problem is of some concern to physical educators, athletic therapists, coaches, athletes, and physicians. The type of injury which occurs in the lumbar spine is dependent on the direction, magnitude, and the point of application of the forces to the spine. This part of the body is susceptible to injury due to the large forces which must be supported, which include the body weight and any external weights, as well as the forces due to very high accelerations of the body parts. Since the lumbar spine is the only connecting column between the upper and lower parts of the body, all the forces must be transmitted via these structures. There are two general techniques of calculating the forces on the lumbar spinal structures, a static approach and a dynamic approach. The static approach may be useful to calculate compression and shear forces on the spine in stationary positions as may be seen in weightlifting. However, the dynamics approach should be used to calculate the effects of the various weights and inertial forces on spinal structures. The most common types of lower back injuries found in athletes were: muscle strains, ligament sprains, lumbar vertebral fractures, disc injuries, and neural arch fractures. The most common serious athletic injury to the lower back was found to be neural arch fractures at the pars interarticularis, or the isthmus between the superior and inferior articular processes. These fractures are known as spondylolysis, or defect in the pars interarticularis of one side of the vertebrae; and spondylolisthesis, a bilateral defect in the pars interarticularis, often accompanied by forward displacement of the vertebral body. The sports in which lower back injuries commonly occurred were also examined, and it was determined that gymnastics, weightlifting and football were the sports in which the lower back is at greatest risk. In order to help to reduce, the high incidence of injuries to this area of the body, athletes should attempt to increase the strength of the abdominal muscles, and to maximize the flexibility of the lower back.