Are they accounting for foot shape?

I remember growing up and I always internally joked that my step dad sounded like a cyberdemon from Doom 2 when he walks. It would shake the walls. He wasn't heavy but his feet are really flat so he naturally hits hard on his heels.

I have some type of arch (I don't know if it's high or normal) but for my whole life people have half jokingly said I should stop sneaking up on them because I guess I walk really quiet.

I never measured or tried to gauge how I walk but after doing a few paces around, I would say the balls of my feet and middle of my foot hit the ground right before my heel. I would say in terms of weight distribution it feels like 70% balls of my feet, 5% middle / arch, 25% heel on each step when it hits the ground. I really feel almost nothing near the middle of the arch, maybe ~30% of the outer part hits the ground.