Medieval Knife and Dagger Fighting

I recently purchased a book on medieval and Renaissance knife fighting. There is a misconception that highly technical martial arts are an "Asian-thing" when, in fact, there is plenty of evidence that armed and unarmed martial arts thrived throughout Medieval Europe. Most of these arts died out as firearms came into wide use, fencing modernized into a sport, and conscription armies changed the methods of training warriors. There was no drive to link combat techniques with spirituality in the West, so that avenue of preservation was lost.

But I digress. When I found the book, I thumbed through the pages and was pleased with the picture sequences and references. The action photos showed many similarities to Japanese and Filipino techniques I've seen. Now you might think this is a red flag; maybe it's just repackaged jujutsu and Kali. That's why I checked the references to existing medieval fighting manuals to see that the techniques tracked to these books and authors. While I do assume that existing knife fighting arts were used to inform the re-interpretation of the movements, I suspect that good technique is just good technique. This is why I like looking at books and films from different martial arts -- to watch the similarities and commonalities. As Bruce Lee points out: what works, always works.

I'm interested in analyzing the book. It seems that much medieval dagger fighting was done with the reverse grip. Since so much modern advice weighs against this grip, I'm curious to see why this grip is popular. It might be related to fighting in armor, as this grip affords power in a stab. You could use it to punch through light armor, or gaps in heavier armor.

I'm also curious about a paradox. Modern science, and I think Sky Ninja has the name of the study, shows that in combat we resort to large, swinging, clubbing motions and fine motor skills go out the window once our heart rate rises above a certain level. So why is it that we have a history of highly developed fighting techniques that cross cultures all demonstrating relatively complex movements? I'm not sure this book will resolve that question for me. But the presence of similar techniques in different, isolated cultures makes me wonder how they developed if no one can pull off the fancy martial arts moves we practice in the dojo?