The manufacture did instrumented testing on the 5th% female Hybrid III specifically looking at potential injury to the legs, femurs and pelvis. The Tummy Shield was crash tested and measurements were taken in all six axial directions as far as the Hybrid III test dummy allows. What they found is that yes, as expected, there is more energy transferred to the thigh, femur and lower pelvis area.
In lower to moderate speed crashes, which make up the vast majority of crashes, the energy is well below the serious injury threshold. After many reported crashes, there have been no reports of anything beyond minor soft tissue injury. In a severe crash there is always potential for injury, or death, as the crash energy has to be absorbed by the body somewhere.
One study in the Health Science Journal evaluated the injuries caused by seat belts as designed and used says, “The lap component [of seat belt] has been shown to affect the lumbar spine, abdominal wall, pelvis, and intra- and retroperitoneal structures. These types of injuries occur when the restraints were worn properly and by occupants appropriate in size for their use.” Seat belts are designed to engage strong bony structures of the body, namely your pelvis (Anterior Superior Iliac Spine) and your ribs/sternum area. In a crash, these areas absorb the crash force from the seat belt, which keeps you secure but also can cause damage to these areas. Pelvic fractures are particularly dangerous because of the vascular nature of the pelvis itself and the proximity to major internal organs which can be injured. For a pregnant woman, in addition to the colon, small bowel, liver, spleen, etc, there is also the uterus, the baby, the placenta which can all be impacted by the seat belt.
The Tummy Shield removes the direct impact to that area and redirects the restraining force to the thigh/femur. The only impact on the lower pelvis is crash energy being transferred from the femur.
With the Tummy Shield we are choosing to direct that crash energy to the legs/femurs (the largest and strongest bones in the body) versus allowing it to compress and potentially intrude into the pregnant abdomen should the occupant “submarine” under the lap portion of the seat belt. As designed the seat belt is intended to engage the Anterior Superior Iliac Spine (ASIS aka hip bone). If the pregnancy has grown to the point of being more anterior of an imaginary straight line drawn between the two hip bones then it will, by default, be compressed by the seat belt in a crash or sudden braking event.
As a former firefighter and paramedic of many years I understand very well that there are MASSIVE amounts of energy that must be managed during a crash and that the human body can only take so much before it results in injury. With the Tummy Shield we are not making any claims that there will not be any injury. We are simply giving mothers a choice as where the crash energy is directed, to her legs and lower pelvis or to the top of her pelvis and potentially into her pregnancy. Placental injury is the most common injury from a car crash that has the potential for severe bleeding for the mom and which compromises the viability of the pregnancy. We believe that by redirecting the crash forces to the legs, though we are increasing the potential for injury there, we are lowering the chances of fatal injury to mom and/or baby. We believe most women would choose a potential leg injury to one that directly affected her pregnancy.