
Originally Posted by
Far from massive
This ^^^
Not unusual at all for the back to hurt lying down. Often this is the result of nerve impingement due to misalignment when the core muscles are in a relaxed state, this can be due to swelling from a temporary misalignment or it can be due to a disc buldge or an actual fracture. Most often and hopefully the case is that it was just a muscle strain, the fact that there is no leg pain or weekness is a great sign.
If you are experiencing enough pain lying that it interferes with sleeping you could likely benefit from anti-inflammatory meds as well as possibly muscle relaxers (if the misalignment is caused by muscle spasm). However a simple trick that often helps and is assuming you sleep on your side, place a pillow between you knees this will help lessen the pressure on the spine while sleeping.