I've never heard of this, but weed can cause muscle tension by creating emotional tension. Even if you're not stressed, anxious, or depressed, I at least find that there's a deep-inside tension that forms when I'm high, and sometimes it manifests itself in muscle that are already susceptable. I recommend you first try closing your eyes, breathing really deeply and slowly, and focus on relaxing every inch of your body. See if that makes it subside; and if not, maybe you're one of those rare people who get a reverse action where inflammation is actually aggrivated. I and a few people I've talked to have that problem; everybody's body chemistry is different.

Hope you figure it out, good luck.