Hello, I was lifting a heavy box 24 hours ago

Patient: Hello, I was lifting a heavy box 24 hours ago and tried to put it up on the closet. I used to do this before and nothing happened but yesterday I felt a sharp pain in the center part of my back. Immediately i stopped lifting the box and stood for a while. I started walking and slowly the pain started to spread all over the Upper Left side of my back, nothing on the lower or right side. It’s been a day and the pain is still there. I cannot make fast movements or turn around without pain. When i sit in the same position for a while, it stops but starts to hurt again. What do you think it is and what can i do for treatment?

Doctor: Thank you for writing to us.I think that you have injured your back. This is causing the pain in the back and strain of it. Please try RICE therapy to help you:Rest the back. Avoid exercise and lifting heavy weightsIce the back for 15 mins at a time every hour for 3 to 4 times a dayCompressing the back is not possible. Please try a massage insteadElevating the back is also tough. But you can try lying on your frontHope this helps you. All the best.