I had shifted my house and got a new mattress 1 year back which was an ortho mattress from wakefit. For last 2-3 months, I am waking up with a massive spasm in my upper back which goes away when I wake up and move around for 15-20 mins. This condition has messed up my sleep massively. Also, the pain started after 6-7 month's use of a new mattress and in winters. I'm doubtful if this is due to the mattress or some other condition. I tried sleeping on a stiffer coir mattress, had the same pain, mildly less.