The Altons at Doom and Bloom Medical have an article up on Blunt Trauma. This first part is an overview of the trauma itself and a later post will discuss treatment.
Blunt trauma is damage caused to the body by a blunt object, such as a club or baseball bat. Blunt trauma can cause bruising, scrapes, fractures, or organ ruptures. It can, in some circumstances, break the skin although a projectile that enters the body and stays there or passes through is considered “penetrating trauma”.
How does blunt trauma cause injury? According to the excellent textbook “Trauma” by Mattox, Moore, and Feliciano: The strain on an area due to trauma is related to the amount of deformation caused, factored with the amount (length) of tissue involved.
Types of Strain in Blunt Trauma
Let’s put “Strain” in four categories: Tensile strain, Shear strain, Compressive strain, and Overpressure.
Tensile Strain: Tensile strain occurs as opposing forces are applied to the same point, something like pulling apart a wishbone at Thanksgiving or, perhaps, a tug of war.
Shear Strain: Shear strain also involves two forces applied to a structure, but not at the same point. Think of a circus strong man tearing apart a telephone book.
Compressive Strain: Compressive strain is directly related to the deformation of an area of impact, similar to what would happen if I struck you in the ribs with a baseball bat or the jack collapsed while you were working under your car.
Overpressure: Overpressure is not unlike compressive strain, but applied to a fluid or gas-filled organ, crushing and, perhaps, rupturing it. An example might be sitting down abruptly on a balloon…