This document discusses common injuries encountered by officiating officials and athletes. It defines key terms like sprains, strains, fractures and dislocations. Sprains are injuries to ligaments connecting bones in a joint caused by overstretching or overusing muscles. Strains involve tearing muscles or tendons connecting muscles to bone from overstretching or contraction. Common knee injuries include tendonitis, meniscus injuries and tears to the ACL from twisting or forceful bending. Fractures are bone breaks that can be acute from injury or stress fractures from repeated stress over time. Dislocations separate the bones forming a joint, requiring medical attention. The document provides worksheets to identify injuries and appropriate first responses.