It does sound like the MS hug to me. It can be different for everyone, but I think it's due to all those little muscles around the ribs and trunk spasming. I felt like the neuro thinks the MS hug is more of a nerve sensation, but if I press around when it's going on I can feel some spots that really hurt, like tight muscle spasms. I hate the hug! But if it's new for you I would ask the doctor and especially since you are on a round of steroids it;s probably good to check in with doctor. Sorry. They should call it something else. Willow