People who work at heights wear safety harnesses to assist lessen the risk of injury in the event of a fall. When the fall is stopped, the harness distributes the force of the fall across the wearer's body. The shoulders, torso, and upper thighs are securely fastened with these fall-protection straps. On the top back (dorsal), they have a single D-ring or web loop for attaching a self-retracting lifeline or shock-absorbing lanyard to a secure anchor point on a building or structure. The D-ring is positioned in such a way that it relieves strain on the wearer's body while also keeping them upright in the harness during and after a fall. Additional D-rings on the shoulders, hips, and chest of some safety harnesses allow for positioning, ladder climbing, and lifting and lowering employees into limited places.