Background. Study physiologic changes occurring during "knockouts" produced
by application of pressure point techniques during martial arts demonstrat
ions.
Methods. Experimental design: prospective analysis of physiologic variables
during and immediately following an acute event. Setting: martial arts dem
onstration carried out at a medical center hospital. Subjects: 12 normal vo
lunteers participating in a martial arts demonstration. Interventions: appl
ication of various pressure point techniques that have been observed to pro
duce states of unresponsiveness in volunteers. Measures: continuous ECG and
video/EEG monitoring with measurements of blood pressure and oxygen satura
tion. Qualitative analysis of EEG and ECG recordings and quantitative compa
rison of heart rate, blood pressure, and oxygen saturation measurements bef
ore during and after the period of induced unconsciousness.
Results. No significant changes in blood pressure, oxygen saturation, cardi
ac rate or rhythm, or electroencephalogram are noted during the knockouts p
roduced by application of pressure point techniques. There was only variabl
e inability for subjects to remember words spoken to them during the episod
e of apparent unresponsiveness.
Conclusions. The mechanism for the state of unresponsiveness produced by ap
plication of pressure point techniques is not related to a significant card
iac or pulmonary process. There is no evidence of reduced cerebral blood fl
ow during this time or of other dangerous physiologic changes. The exact me
chanism for this phenomenon remains uncertain.