The guard who collapsed is part of a ceremonial unit from Scotland called the Royal Company of Archers whose members are mostly over 70-years-old. They've been rotating in 20-minute shifts during the vigil but I can imagine how challenging it is for folks at that age to stand straight and motionless for long periods of time.

Just because you're trained, doesn't mean you always remember your training.

True; OTOH, in a certain sense, complete training means you don't have to remember it; you've been trained to just automatically do it as a default maneuver.

I learned at 17 to never lock knees when standing at attention or parade rest, but to very slightly wiggle the knees, imperceptibly, as you stand there. You never stand motionless.

To this day when standing in line or whatnot, I automatically wiggle my knees to keep from locking.

Just my $.02

No military training and never even knew this was a thing until you guys mentioned it. But found this while learning more about it. Thought I’d leave it here as it seemed most relevant but not discrediting your guys’ comments either. Just more info for those interested.

https://carryingthegun.com/2020/12/22/army-myths-dont-lock-your-knees/

Happens all the time.

Looks like a really fun detail. Good time to forget that training. Wonder if the medic girls are babes. A little farewell to arms with Ms Catherine. You know?