Obstacle Run in Armour - a short film by Daniel Jaquet

There's a bit more to it than that.

Armour of the late medieval period was designed to allow mobility, because it wasn't unknown for a knight to lose this horse in combat. At that point, they had to be able to fight on foot. The other thing to note is that the armour couldn't be too heavy (the knight had to be able to wear it and still fight), which limited how thick it could be - and this is why both crossbow bolts and longbow arrows could penetrate plate armour at shorter ranges.

Those of us who've worn modern ballistic body armour on duty know just how heavy and uncomfortable it can be, especially when you're carrying all the rest of your kit. Just the armour weighs 12kg or more (depending on what level or protection you need) and your kit adds another 30-40kg to that. Add your personal weapon of choice (with extra ammunition, because you always carry as much ammo as possible) and you're talking about carrying anything up 85kg. This is quite a lot more weight than most medieval knights would carry, even if you include their sword and shield.

Mobility isn't just about what you're wearing, its also about what you're carrying. The video doesn't really emphasise it, but you can see on it how the various bits of kit carried by the fireman and the soldier get in the way on the obstacle course. And this is without any of them carrying weapons (or in the case of the fireman, a hose) or radios.

Medieval swords are surprisingly light, only 2-3kg. An automatic rifle like an M16 weighs about 3.5kg including ammunition, and they're about the same length (about 1m) as a longsword of the sort used by knights. In short, swords are about as cumbersome as modern automatic rifles, and have about the same impact on mobility.

In short, when you're writing, don't assume that a knight in armour is any less mobile or any less quick than a modern soldier.

 

I’ll let you guys know if things work out for my my comparison. I’m about to try to start up with the armor combat league, and do some training with hopes of competing. I’m currently a full time city firefighter and a marine combat vet with 3 combat tours. So once I get buckled down and start training in full Knight armor, which I assume will probably be after months of training in gambeson, I’ll let you know what I think between the three of these. As of right now, firefighting gear is more cumbersome mobility wise that a full military combat load, but the military combat load is more off balance due to the ammo you carry and feels heavier.