160 Introduction to Anatomy & Physiology Common Joint Injuries The freely movable joints of the human body are subject to significant wear over the course of a lifetime. Both acute and overuse injuries affect the joints. The etiology, strategies for prevention, pathology, diagnosis, and common treatments for these common joint injuries and disorders are summarized in Figure 4.38. Sprains Sprains are injuries caused by abnormal motion of the articulating bones that results in overstretching or tearing of ligaments, tendons, or other connective tissues crossing a joint. The most common site of sprain is the ankle, and the most common mechanism is injury to the lateral ligaments. Lateral ankle sprains occur frequently because the ankle is a major weight- bearing joint and because there is less ligamentous support on the lateral than on the medial side of the ankle. Pain and swelling are the symptoms of joint sprains. Immediate self-treatment should include R.I.C.E.: Rest. (Avoid activities that exacerbate the pain.) Ice. (Apply an ice pack as soon as possible for 15–20 minutes and repeat every two to three hours while you are awake for the first few days after the injury.) Compression. (Use an elastic bandage to gently compress the joint until the swelling stops. Be careful not to tighten the bandage to the point of stopping circulation.) Elevation. (Elevate the injured joint above the level of your heart, especially at night, which allows gravity to help reduce swelling.) Over-the-counter pain medications can also be taken. Serious sprains should be evaluated by a physician, who may ask for an MRI to determine whether a ligament or tendon has been completely ruptured. Such cases may require surgical repair. Dislocations When one of the articulating bones is displaced from the joint socket, the injury is called a dislocation of that joint. Dislocations usually result from falls or forceful collisions. Common dislocation sites are the shoulders, fingers, knees, elbows, and jaw. In females, striving for an extremely low weight can cause a dangerous condition known as the female athlete triad. This condition involves a combination of disordered eating, amenorrhea (ah-men-oh-REE-a)—having no period or menses—and osteoporosis. Because this triad can cause negative health consequences ranging from irreversible bone loss to death, friends, parents, coaches, and physicians need to be alert to the signs. Female athletes participating in endurance or appearance-related sports are most likely to be affected by the female athlete triad. Disordered eating can take the form of anorexia nervosa or bulimia nervosa. Symptoms of anorexia nervosa in girls and women include a body weight that is 15% or more below the minimal normal weight range, extreme fear of gaining weight, an unrealistic body image, and amenorrhea. Bulimia nervosa involves a minimum of two eating binges per week for at least three months an associated feeling of lack of control use of self-induced vomiting, laxatives, diuretics, strict dieting, or exercise to prevent weight gain and an obsession with body image. Although the incidence of osteoporosis among female athletes is unknown, the consequences of the female athlete triad are potentially tragic. Amenorrheic, premenopausal female athletes are known to have an elevated rate of stress fractures. More important, the loss of bone that occurs may be irreversible, and osteoporotic wedge fractures of the vertebrae can ruin posture for life. Female athletes who are extremely thin and are missing menstrual periods, may have disordered eating, or experience stress fractures should be evaluated by a medical professional to check for bone density. Treatment for the female athlete triad often requires a team of medical professionals. The team may include a primary care provider, gynecologist, nutritionist, and psychological counselor. Chec k Your Understanding 1. How does osteoporosis differ from osteopenia? 2. What two eating disorders are common in women diagnosed with the female athlete triad? Copyright Goodheart-Willcox Co., Inc.