Treatment For Muscle Spasm

Hi, i had slip disc surgery in past (2006) and L4&5 was removed. Iam suffering from muscle spasm for last 8 days, dr saw my x ray and reccomended me bed rest/ hot cold water compress and pain killer.I have recovered from pain but still my upperbody is inclined on one side and feel a lock in my back.It hurts when i try to straighten my body/ sit for 15 minutes.pls advice