[Stress on the human body when falling into a rope harness and its sequelae]

The stress during holding a fall of a climber was evaluated in practical tests with human subjects. Depending on the situation of the fall forces up to 4 kN are acting on the body through the harness. With extreme rope friction at the rock and running belays the forces can increase up to 6.5 kN. These forces depend on the method of belay and the situation of the fall and are mostly independent from the weight of the climber. Therefore light climbers are subjected to greater deceleration forces than heavy climbers. For a given force of 4 kN the biodynamics during impact is shown. If only a seat harness, surrounding only the pelvis, is used, the bending loads on the spine exceed under certain circumstances the human tolerance considerably. Whiplash effects, head down falls or severe pressure loads on the viscera can also occur. Besides these acute injuries chronic injuries of ligaments of the spine and the invertebral discs can occur because every stress overcharging the muscles must be taken up by the ligaments.