I am experiencing lower back pain for the past week. It hurts to move, soreness and stiffness. Some pain in one side of my buttocks now and again. I am about 30lbs overweight, need to change my mattress that I sleep on and recently had a very demanding day, prior to feeling this way, where I had to rush around a lot, walking and running which I am not use to. I have also been ill with a gastric bug recently for a couple of days. I have had sciatica in the past also, when pregnant. I have a bit of bruising where the pain is located from but this could be from applying pressure to the spot which when done alliviates the pain.