While flexible body armor may protect against penetration from projectiles, its use may be associated with blunt trauma to underlying structures. This is termed behind armor blunt trauma (BABT). In the Middle Ages a thick tunic was worn under the armor to protect against such injury.


Mechanisms involved:

(1) deformation of the armor at the point of impact

(2) dissipation of the projectile's energy


The most common precipitating event is a high energy bullet striking the armor.


Possible injuries:

(1) bruising and hematoma in underlying skin

(2) contusion to or rupture of the spleen

(3) contusion to or rupture of the liver

(4) contusion to heart

(5) blunt trauma to the spinal cord or peripheral nerve

(6) rupture of distended bowel

(7) contusion to the lung

(8) fracture of underlying bone

(9) contusion or rupture of distended urinary bladder

(10) contusion to the kidney


Cannon (2001) recommended overnight observation in the hospital for BABT, with the following evaluation:


Site of Impact



serial chest X-rays

cardiac region

serial ECG and serum cardiac enzymes


serial examinations for peritoneal irritation


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