A lot of the leg press depends on your leg and foot placement
stabilisation demands are also lower as you're in a machine so you will probably get some extra range of motion you wouldn't get standing and a lot of leg presses got into some sever lumbar flexion which will also provide some more range of motion so now you're entering ranges of motion you probbaly never have before, under load, a s**t load of soreness is your calling card for 2 - 3 days