Why would my lower back hurt more from leg pressing than squatting? I have no problem squatting below parallel and I do every week. Last week after not leg pressing in a while I added that into my workout and my back felt horrible after. Could this be a foot position issue, or am I lowering the weights too far?
Lots of people lift their arse out of the seat when it gets lower without realising, could be something to do with it?
Video yourself doing them next time
do you hold your lumbar arch when you are leg pressing like you do when you are squatting?
The leg press puts alot of tension on your hips, especially if it is an incline leg press. See if your hips posteriorly tilt(butt tucked under) during your leg press, especially at the bottom of your lift. If this happens your lumbar spine is not supported and all that tension placed on your hips get transferred to your lumbar and sacral spine! This will surely aggravate a preexisting injury or possibly lead to a new injury.
When doing a squat your hips are in a neutral position or anterior pelvic tilt position(butt out). This is a more natural position for your spine where it can be easily supported by your deep abdominal muscle and spinal erectors. This reduces compressive forces and stress on each lumbar vertebrae, and each intervertebral disk.
Hope this helps!