Ive seen some pretty good growth switching to high reps low weight work sets, but legs are lagging behind because of a lower back injury hurting my ability to go all out on squats and deadlifts. Is there anything I can do to help stimulate more growth. One suggestion ive gotten is incorporating two leg excercises on my arm day which well help not only my legs but my arms, anyone else heard of this or have any suggestions?
Hack-squats, split-squats, leg press for a start.
I never heard of that jackassy approach you mentioned - extra leg work on arm day. If you think it might work, try it.
If you have an injury, get help, and don’t repeat what caused it.
Try one-legged exercises like lunges, one-legged stiff-legged deadlifts, and stepups; and machine exercises like leg curls, leg extensions, hack squats, pull-throughs, and leg presses.
Get on a leg press
Try working legs more often, like three times a week. You won’t be able to go as heavy, which will accommodate your injury, and the increased volume might break the log jam for you (I know it did for me).