It happens to everyone. Barbell deadlift gone wrong just a tiny bit. Picking up your dog or kids not quite right. Here is what to do when you pull a muscle in your back.
Rest
Stop whatever you are doing, and do not return to the activity for a while. Normally, with pulled muscles, you can go back to doing some kind of exercise a week or so after the muscle pulling. But do not go back to your regular program for 1-2 weeks with resting some.
Laying directly down can hurt your back more, so placing a pillow under your knees can help support your back.
Ice & Heat Therapy
Although it might be tempting to go to heat right away, ice is your best friend. Icing with a cloth for 20 minutes at a time, especially the first few days after the incident is ideal. After at least 48 hours, you can switch between cold & heat therapy to increase blood flow and flexibility as needed.
Medication
In addition to ice, ibuprofen can be used to bring down inflammation.