Test Start and Approach to st Hurdle

1st QUESTION: What forces the hurdler to modify the drive phase with respect to a 100m sprinter?

Get to your feet early, gain early visual contact with the first fence and ensure a precise attack without final corrections
Maximize exclusively horizontal speed without postural changes
Lengthen the drive phase until after the first hurdle
Avoid using high heels to maintain stability

Five acceleration steps and three control steps
Four quick steps and four short jumps
Start, seven steps of increasing acceleration and an eighth step to prepare for take-off
Departure, eight identical steps and take-off without preparation