Diagnose where it fails
If the bar stalls at the knee, your glutes and hamstrings are not finishing the hip extension. If your upper back rounds and shoulders roll forward, it is a mid back and lat weakness letting the bar drift out front.
Lockout failures usually come from weak glutes and upper back, so add rack pulls, block pulls, and heavy holds.
A stalled lockout is typically a weak posterior chain finish (glutes and hamstrings) or a rounding upper back that loses tension near the top. Build it with rack pulls or block pulls from just below the knee, plus dedicated hip thrusts and heavy shrugs or holds. Also fix the setup, pulling the slack out and engaging your lats keeps the bar close so lockout is less of a fight.
If the bar stalls at the knee, your glutes and hamstrings are not finishing the hip extension. If your upper back rounds and shoulders roll forward, it is a mid back and lat weakness letting the bar drift out front.
Rack pulls or block pulls from just below the knee overload the exact range you fail in. Work them heavy for 3 to 5 reps, and add hip thrusts for glute lockout strength and heavy holds or shrugs for grip and upper back.
A bar that drifts away from your body makes lockout brutal. Engage your lats to pull the bar into your thighs, take the slack out of the bar before you pull, and keep the bar dragging up your legs so the hips finish efficiently.
Lockout failures usually come from weak glutes and upper back, so add rack pulls, block pulls, and heavy holds.