a brief and incomplete theory of muscle tension risk in meditation:

[See a physiological note at the bottom, too.]

Untrained operation of the mind is relatively more Spreading, than Gathering, of Relevance.

(Trained operation of the mind is relatively more Gathering, than Spreading, or, perhaps, rather, there’s a nuanced, sensitive, responsive, situated, contextual balance.)

Relevance is original sensory impressions.

Spreading is sort of, loosely speaking, following implications to reach conclusions, increasing transitive closure.

Gathering is sort of, loosely speaking, regathering spreading, reevaluating relevance, and refactoring (relative or deep) premises and presuppositions.

One property of a mind is unresponsive (occluded, inaccessible, layered) Momentum, with respect to spreading.

Sometimes relevance-to-be-gathered is arranged relatively nearby. Sometimes relevance-to-be-gathered has Outliers, that is far away, long-range relevance. This can be things like, say, an early childhood experience, or, say, a traumatic experience from any time in one’s life, that was somehow unique or isolated, and, so far, seemingly irrelevant to most things.

Momentum, in long-range interaction with not-yet-gathered outlier relevance, causes tangling, twisting, or even iterative wrapping. (It's almost like one's current "location," at one "pole," and the long-range relevance, at another "pole," creates a bar, an axis, a line segment, through the system. And then, unfortunately/unluckily, things can twist and wrap along/around that axis.)

Eventually, momentum is bled off, integrated, metabolized, harmonized. And, eventually, long-range relevance is finally gathered.

Once essentially ALL relevance is gathered, with respect to some nebulous something, the system can, (loosely, relatively speaking) somewhat sharply, re-conceptualize, re-preference, re-plan, re-expect--that is complexly (perhaps) lock-and-key Pivot to new, niche-fit intentionality around that relevance, and sort of now re-spread, anew, from that relevance. (Premature pivoting attempts, perhaps via momentum, are sources of twisting.)

(Twisting, tangling, wrapping eventually accumulates into noticeable muscle tension.)

Regathering, untwisting, etc., nonmonotonically releases/relaxes muscle tension. Sometimes completed or near-completed gathering-into-relevance is accompanied by immersive flashbacks and/or insight.

The above is somewhat simplified, and doesn’t go into “safe to look then look,” contextual equanimity, “inner space,” or lack thereof, "motor output contention," "immediate/mediate/long-range contradiction," and more.

I am not a doctor and this is not medical advice (assertions below are personal experience and opinion even if stated more generally, etc. etc.), but it can also be good to keep an eye on your diet or supplementation, e.g. especially magnesium but also, in relation to magnesium, potassium, calcium, vitamin D and K2, etc. They all kind of balance and rate limit and sometimes absorptively compete with each other, so if you perturb one you potentially have to keep an eye on the others. (Generally, I try to let my sense of taste sort things out, and I try to stick with food over supplements, but, for all sorts of reasons, such as challenge getting enough of something in one's diet, of course, it can make sense to supplement sometimes.) Magnesium (plus maybe to a slightly lesser degree potassium? or vice versa, even, depending on which is rate limiting) is maybe sort of a regulator of "global muscle tone," and all other contingent variations of muscle tone and tension maybe kind of ride on that. So if you feel generally tense that might be something to explore, too, to de-confound: For me, when I increased my magnesium a bit, there was almost a whole-body "writhing" of muscle, across the entire surface of my body, reducing and rebalancing tension everywhere while still somehow like fractally preserving muscle tone ratios between different areas, or something. It seemed net good, maybe a little bit more (non-critical) "global slack" to work with, meditatively, though it introduced some initial confusion because the feedback from the landscape was a little different.

Very not medical advice, but, to my knowledge, some supplements are relatively safe (magnesium, I think!) and some supplements may increase all-cause mortality risk (I think! Though perhaps not if paired with other things like vitamin K2 and vitamin D or something). Personally, at least at the time of this writing [20230306], I supplement magnesium, for example, but try to only get calcium through diet, for example.

Also very not medical advice---for supplements, I sometimes play with powdered forms to see if my taste buds arrive at a reasonable-seeming preference, so that I can somewhat or completely offload tracking to my body. "Chewable gummies" work better, in some sense, because they'll have a distinctive flavor for which the body can learn an association between nutrient and flavor really fast. But gummies often contain a lot of sugar or whatever other weirdness. So, powders---they can be a bit tricky because they're so dense and so the body temporarily "saturates" if you put some on your tongue (careful of repeated applications burning your tongue---you can also of course mix with a liquid and this all still mostly works) but then if you wait thirty seconds to ten minutes, you'll find that you might be able to repeat this many times (body: "sure I'll have some more") until the final time you try, after a delay, the body is like, "nope, I'm good, for a longer while, now." Please note this is potentially annoying and time-consuming and has all sorts of pitfalls, so sometimes you might just want to pop capsules, etc., etc., depending. Please make sure you're not accidentally taking too much if you play around with powders and liquids and taste (ditto capsules and pills, still, too), and again this is not medical advice.

But this all seemed worth mentioning, in case it's useful to someone else.

Also, because of genetics, childhood dietary experience, and other factors, not everyone will have a reliable sense of taste/feel/desire for every nutrient, and not everyone will be able to learn a reliable sense of taste/feel/desire for every nutrient, for how much they want over the course of a day. So relying on numbers is certainly ok, too, if it seems like it might be a good idea to get more of something, through either diet or supplementation. Talk to your doctor, etc., etc.