Chapter 6 The Muscular System 199 Copyright Goodheart-Willcox Co., Inc. tibia or inflammation of the periosteum of the tibia. The muscles potentially involved include the soleus, tibialis anterior, and extensor digitorum. SELF CHECK 1. Describe the differences among the three classifications of muscle strains. 2. Why are athletes more likely than others to have problems with strains? 3. What causes swimmer’s shoulder? 4. What is the difference between tennis elbow and Little Leaguer’s elbow? 5. What is the role of the neuromuscular system in whiplash injuries? Rotational Injuries of the Shoulder Repetition of forceful overhead motions at the shoulder (as in throwing in baseball, spiking in volleyball, and serving in tennis) can lead to inflammation of or tears in the muscles and muscle tendons surrounding the shoulder (Figure 6.27). A similar condition experienced among competitive swimmers is known as swimmer’s shoulder. Improper motion mechanics increase the likelihood of these types of shoulder injuries. The symptoms include pain and stiffness that accompany overhead or rapid movements of the shoulder. If not treated, the pain can become constant. Treatment includes application of ice, rest, and, when necessary, surgical repair. Overuse Injuries of the Elbow Epicondylitis involves inflammation and sometimes microtearing of the muscle tendons that cross the lateral and medial sides of the elbow. If untreated, the condition can worsen, leading to swelling and then scarring of the tendons near the elbow. Lateral epicondylitis, which is reported in 30%–40% of tennis players, is known as tennis elbow, although it also can result from activities such as swimming, fencing, and repetitious hammering. Medial epicondylitis, known as Little Leaguer’s elbow, can result from repeated throwing, especially with improper pitching mechanics. Both lateral and medial epicondylitis commonly occur among amateur golfers. Understanding Medical Terminology The suffix -itis means “inflammation.” Numerous medical conditions involve inflammation of a part of the body. The names for all of those conditions contain the -itis suffix. Shin Splints The term shin splint is often used to describe pain localized to the medial lower leg. The condition is an overuse injury that typically arises from running or dancing—particularly running on a hard surface or uphill. The cause of the pain is believed to be micro- damage to the muscle tendons that attach to the sirtravelalot/Shutterstock.com Figure 6.27 Pitching in baseball is stressful to the shoulder and elbow joints.