According to the AHA, “…a rescuer should push down at least 2 inches, but no more than 2.4 inches on the chest…” for both adolescents and adults. Furthermore, Clifton Callaway, M.D., Ph.D., of the University of Pittsburgh and chair of the AHA’s Emergency Cardiovascular Care Committee says, “…people should not be afraid of pushing hard…Ribs bend with chest compressions and the ‘injury’ is usually very mild. It definitely is not life-threatening.”