Where do repetitive stress injuries typically occur?

See below. Depends on age and type of activity. Kids get repetitive injuries in areas of growth like the knee, heel and other apophyseal areas. Adults can get injuries anywhere where there is repetitive motion and poor mechanics such as the wrist (carpel tunnel), elbow, shins, lower back, knee, shoulder etc. The key to avoid these is adequate warming up and stretch, stretch and stretch!
Depends on activity. This depends on the activity. Any activity that overuses or puts continued or repetive stress on a single body part or joint can get this. For example, tennis players can get these in the elbows and wrist, runners in the feet, legs, and knees. Factory workers or typists can get this in the wrist or hands. Boxers....Well, you get the point!