Bending correctly can help you avoid back strain and injury. Here are some tips for correct bending:
Don't stand with your feet together. Instead, keep them shoulder-width apart.
Bend at the hips and knees, not at the waist.
Pull in your belly (abdominal) muscles and tighten your thigh muscles.
Keep your spine straight. Don't try to tuck your buttocks under.
Place a hand on a wall or fixed heavy object, such as a desk for support, if needed.
If you need to bend all the way to the floor:
Lower yourself to 1 knee. If needed, place 1 hand on a sturdy, stable object to steady yourself as you move downward.
Rest an arm on the raised knee.
Bend at the hips and knees, but not at the waist, to get closer to the floor.
Don't round your shoulders or hunch your back or neck.