Hug a med ball on your hips and thrust away.
Keep the ball steady on your hips and finish flat, ribs down at the top.
With your upper back on a bench and a medicine ball hugged on your hips, the hip thrust takes your glutes through a longer arc than any floor bridge, from a deep hip fold at the bottom to a hard locked-out squeeze at the top. The hamstrings assist the drive while the ball supplies resistance you can hold steady through every rep. It is the entry point into loaded hip thrusting, teaching the pattern before heavier tools come out.
Until your torso and thighs form one flat line, shins roughly vertical, ribs tucked down. Beyond that you are arching your back, not extending your hips. Flat and squeezed at the top is the finish line, every rep.
Just under your shoulder blades, so your upper back pivots on the pad as your hips rise and fall. Too high and you slide around, too low and it becomes an awkward bridge. Your eyes should look forward at the top, not at the ceiling.
For learning the pattern and for higher-rep glute work, absolutely, most people rush to heavy loading before they can even lock out properly. Own a strict pause at the top for sets of 12 to 20 first, then chase heavier resistance.
