I suffered my first low back injury in 1972. I suffered another one in 1975 and a third one, in 1979. They were all diagnosed as low back strain, which they mostly were. But I thought using the proper body mechanics I could lift or assist anyone. I finallt herniated my L4-5 disc in January of 1988. You cannot lift a patient by yourself, not even with the patient's assistance. You cannot transfer a patient alone. You need to use another nurse and a slide board. Each time you strain your low back, you are doing damage. And one day, you will damage it to the point of herniating a disc.
Woody