Does repositioning prevent pressure sores from happening?

Yes: Pressure sore are caused from excessive pressure on a specific area of body: usually develop when one is in a specific position for a long time such as in bed for days without movement.

Yes yes yes: It only takes a 2 hours of mederate pressure to cause a pressure ulcer. Unloading and shifting occur unconsciously when we have normal sensation and are able to move. After a nerve or spinal cord injury, or if we are immobile, we loose this ability and have to consciously unweight and reposition; otherwise a pressure ulcer will occur.