It was throughout the entire run. I’m not talking about leaning back, which you also did. I’m talking about arching your lower back. It is running too tight and could also be from being weak all around when in the sprint position.
And I took an average of a few 100m walks to determine how many strides it takes, and then calculated that into strides per 10m. Then I placed an object at the finish line, and had my friend stand there to clearly show it. I don’t think it’s hard to believe my 30m is ranging from 4.2 to 4.3s though…that’s a slow time. Maybe I’m doing this wrong, but I stopped counting frames when any part of my body crossed the line, whether it be my hand or my knee or my foot, or whatever. Is that wrong to do? Also that’s without reaction time.
I think it is substantially slower than 4.2-3. It looked like a 12low to mid level 100m acceleration–maybe even slower.