After their FA Cup victory over Brighton, Pulis revealed the 29-year-old was experiencing problems because of an issue with his jaw that Stoke's medical staff were working on.
"He's okay - it's more his jaw-line which is affecting his back than anything else," the manager said.
"He has got a defect in his jaw and we have got a specialist to do a jaw brace for him.
"We are hoping the alignment will be sorted out and Matty will be all right from then on."
He continued: "His back will stiffen up sometimes because the alignment in his spine is just a little bit over, and apparently it has all come from his jaw-line. It amazes me.
"I think a lot of people now wear them (a brace) and I think a lot of clubs get people tested.
"The first thing our medical staff do is look at the back. It is so important - they look to make sure the alignment is right because that can affect hamstrings, calf muscles, cramping in the back.
"Being old-fashioned, it amazes me, but if it works, lets get it done."