wiki/Progressive_muscle_relaxation
This sounds like a great tip, and I believe this will help a lot of people with various degrees of difficulties in muscle tensions and sleep problems. But let me play a devil's advocate here, I'm a male, throughout my life, I never seriously got injured physically and most of my jobs I've had covered daily requirement of enough exercises. I'm back to sedentary lifestyle which called za-zen, I need somebody to hit me with zen stick, I haven't look into it much, I'm sure my muscle will tense up along with my ki or something.
Hmm,,,okay, I think this is worth a try for everyone, for serious minds only though. Never start with wikihow and their manga instructions, that's how minds get dumber, millions people get mind controlled by the institutions this way, no brains left behind, whatever happened to that?
Well, anyhow, PMR sounds legit, I will be paying attention, thanks!