It makes sense that your body would be very relaxed when sleeping and falling asleep. But I've recently been made aware of the tiny contractions that muscles make when we don't even realize it, and just a small amount of muscle holding can cause tension within an entire muscle group. A few nights ago I was falling asleep, finally warm under the covers. I wasn't stressing about anything, was looking forward to the next day, breathing evenly, when one of my cats started kneading my back. My back released and I then noticed that my shoulders loosened...they had been hitched up to my ears! Then I felt my jaw drop, I had been clenching my teeth a bit while I thought I was relaxed and about to fall asleep. The body worker in me flashed facts I'd learned about how even slight muscle tension can lead to serious chronic pain. Where else was I holding tension without realizing it? I let my mind scan my body section by section starting at my toes, then up to the knees, all the way up to my head. If I felt tension, say in my thighs, I'd shake, slightly move, rub, or just tell that body part to relax. A deep breath or two in through the nose and out the mouth worked wonders on some areas, especially on my neck. That's all I remember from that night- I happened to fall, very relaxed, into sleep after doing this, but I am now trying to make it a point to check in with my body more often at night and throughout the day. I get a lot of headaches, migraines, and upper body pain- but I'm pretty confident that I can bring more effectiveness to the weekly massages I've been getting on these trouble spots by being aware of these holding patterns on my own every day. And an added bonus: My mind has felt more relaxed after a few moments spent relaxing my body and breathing.