There has been a recent increase in research papers, medical studies and trade-related accident investigations concerning a physical phenomenon known as "suspension trauma." It goes by several other names, such as harness-induced pathology, suspension syncopal incident, prolonged motionless suspension syndrome or simply post-fall faint. As we will discover, not even a strong and well-conditioned individual, competently fitted with a suitable harness, is capable of withstanding the effects of suspension very long without serious, and possibly fatal, consequences.
Any asymmetrical applications of force to the harness, partially dissipated by the deceleration device, is terminally applied to the pelvic region. While impact forces are dissipated by all of the harness straps, they are rarely uniformly applied. The lower extremities ultimately receive a dominant percentage of the load. As the "slamming effect" at termination is delivered by the lanyard to the contact areas of the body, the nylon fibers begin to stretch around the upper legs, groin and buttocks. The harness straps reach maximum elongation and then quickly begin to contract against the soft tissues of the thighs, creating a tourniquet effect to both the legs and lower abdominal muscles.