Leg Extensions, Seated Leg Curls, 45 degree extensions, hip thrust, hip adductor, hip abductors. You don’t need movements that load your spine to hit your back muscles effectively.

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Work on expanding air dynamically 360 around your belly when you do movements, i used to try to always crunch my abs in hard to brace, but it’s filling it with air and not straining my back muscles that’s helped me. Also ankle stability, proper hip hinging, glute bridges

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