The bent-leg donkey kick, in which the knee is bent to 90 degrees while the leg is lifted,
shortens the hamstrings and reduces the participation of the hamstrings in the movement.
Because the hamstrings are weakened, the stronger glutes will pick up the slack, which
makes this movement a more targeted glute exercise because it requires less hamstring and
spinal erector torque while keeping the tension on the glutes. Squeeze the glutes at the top of
the movement and keep the spine straight as the hip rises.