The type of explosion studied theoretically in the determination of the causes of explosive blast traumatic brain injury (bTBI) assumed an open field explosion. Things become much more complex in a non-free field or enclosed area, such as a building, doctors have learned.
In an enclosed space, the shockwaves can reflect from walls, ceilings, and other objects, creating a “complex wave field.” An explosive blast under such conditions creates an individual scenario that cannot accurately be predicted or replicated.
Hospitals have noted there has been the assumption that pressure, and not the shockwave, may cause bTBI, but such studies may not be valid. These studies suggest the pressure of the blast leads to failure of air-filled organs, such as the lungs and the bowels. Therefore, if this is true, lungs should be injured more often in explosions. Clinical experience shows this is not the case. The bowel is generally uninjured unless there is penetration from shrapnel. Brain injury was not studied and some believe interceptor body armor may protect those organs from the blast. There may even be other physical forces that play a role in explosive blast injury.
There are more than pressure waves to an explosive blast, researchers have learned. Conventional military explosives also release light, sound, heat, and electromagnetic energy, some of which can also cause injuries. It is uncertain how much each of these contribute to bTBI, if anything. The only thing that is certain is that no one can if these are potential causes of bTBI.