Friction usually, but not always, accompanies shear. Friction is the force of rubbing two surfaces against one another. Shear is the result of gravity pushing down on the patient's body and the resistance between the patient and the chair or bed. When combined with gravity/force (pressure), friction causes shear, and the outcome can be more devastating than pressure alone. This figure highlights many of the common practices observed in healthcare facilities that contribute to friction and shear and alternatives for prevention.