@alexsigrist and anyone else with cramps along shin and ankle that can't be stretched out. I also have a chronic issue with massive fasciculations and muscle cramps all over my body for decades. Mine is part of a rare hereditary neuropathy, but it's getting worse with age. Like you said, the cramps alongside your shin and in my ankle happen while I'm sleeping and there is no way to stretch them out. Manual massage does little for them. What I found works is this sports massager. Look on Amazon for the "Thumper Sport Percussive Massager - Deep Tissue Home use Massager for Muscles, Back, Shoulders, Legs, arms" so you can see what mine looks like. I have a much cheaper Walmart version I bought 30 years ago. The Thumper was recommended decades ago for my neck and back pain, bu it is too painful for my pain sensitive body. I did keep it just for working out these odd muscle cramps. I like the double head on it so it surrounds the cramp. I turn it all the way up and it gets these cramps out in a minute or two. I think it's the vibration that takes out the cramp more than the massage. It hurts when I use it, but it's so worth it and then the cramps stay away for the night. If it happens to you every night, you might even try using it before you go to bed as a preventative measure. Like some others here, it hurts just to touch my shins at any time. Just putting lotion on hurts. Good luck!