I have been to many tournaments and viewed/participated in this sort of conduct. This style of movement is deliberately attuned to muscle control. It simulates not only the ready stance they take before and after but also displays crisp and precise movements. The purpose is to show they have
control of every muscle in their body. Refinement and mastery of the body.
The reason I say this is because you are watching the wrong things to simulate this sort of walk. Their legs aren't stiff. They are precisely placed and moved at a speed that controls body weight and balance. They are not walking heel to toe as most of us do in shoes they are walking on the balls of their feet. If anything they are graceful. (Think cranes stalking fish in the water.)
Their shoulders are not bouncing around because they are keeping such movement in measured increments and more importantly SLOW increments.
Think of it like tip toeing. Not silly but sneaky tip toeing. Gradual measured movements.
To capture this effect you will need to do several things.
Study animation to understand the speed at which you have to transition a sprite to capture speed effects, study how their entire bodies are moving and not only their feet and legs, and do something about the super exaggerated movements that you have in your sprites. Your arms are noodles, the shoulders are all over the place, and your legs function like 80s action figure toys. (The point is that your figure seems to have very little control of his movements. ~The opposite of your goal~)
I think you could probably capture the effect if you tried those things, even without really developing your figures shape and body. I have seen it done with stick figures.
You could also see this type of movement in military drills, ceremonies, balance competitions, religious and royal processions. Hope this helps.
