While not a scientific study, well worthwhile to read:
In the past I have always taught knife defense with the weapon in the lead hand and visible. To the general public this would seem like the way it should be, after all in order to stab or cut you it would have to be out and close to you? The evidence put forth in this article would suggest that is not the case.
After reading, I have changed my weapon defense methodology to concentrate on pre-incident cues. The blading of the body, the hiding of the weapon hand. The empty hand coming out for the initial contact. I now am teaching movement off line and away from the hidden (rear) hand, forcing them to draw across their own body. I believe that this type of movement affords the highest probability of success, be it against the empty hand or the weapon hand.
The basic problem seems to be proximity. Obviously more space would help with reaction time. Most times space is not an option or is forgotten in the heat of the moment. If we concentrate on pre-incident cues it may serve to keep our awareness higher and make us think about space and proximity more?
Any thoughts out there?