I got to wondering what exercise that exists that most closely relates to the motion of a sprinter from the blocks to the drive out of the blocks.
A lot of exercises that work on the posterior chain do a lot of the knee extension part of the sprint but I don't notice a lot of resistance in the hip extension.
Maybe the use of rubber bands at the waist while doing something like the squats.
hip thrusts useful for hip extension but not so much for knee extension.
And me as usual I like to draw out my problems, which you can see below with some noted exercises that closely resemble but there is always that balance of specificity with convenience. such as doing step ups but adding hip bands to add resisted hip extension.
box squats with the shins straight and hips drawn back but keeping barbell over toes. But would create mechanical disadvantages and so on.