The pathophysiology of free-fall injury.

The spectrum of injuries created by a free fall are governed by distinct physical properties, of which the height of the fall and the nature of the impacted surface are the most important factors. Other determinants include the victim's age and weight and the position at landing. Orthopedic injuries frequently are encountered in falls from two stories and less, and are largely determined by the position at landing. Visceral trauma, produced by deceleration forces, frequently involves the liver, spleen, lung, heart and aorta, and must be suspected in falls from three stories and more regardless of the landing position. Mortality from a six-story fall onto a hard surface such as concrete is almost 100% for adults, although considerably less for children. Falls onto softer surfaces, including water, are better tolerated. By appreciating the physical principles that dictate the type and degree of injury, one may correctly diagnose and manage free-fall injuries.