I do wish the head articulated.
To lift with your legs ALWAYS look up first. In a healthy person looking up first drives the hips under the back setting the legs to do the lifting. It's automatic. Always look up first. I have taught this to many a deadlifter. Always look up when lifting.
Try squatting to the floor next to a table or something like that to use for balance. Bend your face toward the floor. Your butt sticks out, you'd lift with your back. Then look up while in the same squatted position. You'll feel your hips drive under you. Always look up when lifting!