Hydrostatic Shock - Energy Transfer Required For Remote Neural Effects

Energy Transfer Required For Remote Neural Effects

The work of Courtney et al. supports the role of a ballistic pressure wave in incapacitation and injury. The work of Suneson et al. and Courtney et al. suggest that remote neural effects can occur with levels of energy transfer possible with handguns, about 500 ft·lbf (680 J). Using sensitive biochemical techniques, the work of Wang et al. suggests even lower impact energy thresholds for remote neural injury to the brain. In analysis of experiments of dogs shot in the thigh they report highly significant (p < 0.01), easily detectable neural effects in the hypothalamus and hippocampus with energy transfer levels close to 550 ft·lbf (750 J). Wang et al. reports less significant (p < 0.05) remote effects in the hypothalamus with energy transfer just under 100 ft·lbf (140 J).

Even though Wang et al. document remote neural damage for low levels of energy transfer, roughly 100 ft·lbf (140 J), these levels of neural damage are probably too small to contribute to rapid incapacitation. Courtney and Courtney believe that remote neural effects only begin to make significant contributions to rapid incapacitation for ballistic pressure wave levels above 500 psi (3,400 kPa) (corresponds to transferring roughly 300 ft·lbf (410 J) in 12 inches (30 cm) of penetration) and become easily observable above 1,000 psi (6,900 kPa) (corresponds to transferring roughly 600 ft·lbf (810 J) in 12 inches (0.30 m) of penetration). Incapacitating effects in this range of energy transfer are consistent with observations of remote spinal injuries, observations of suppressed EEGs and apnea in pigs and with observations of incapacitating effects of ballistic pressure waves without a wound channel.