Reddit mentions of The Psychology of the Body (LWW Massage Therapy and Bodywork Educational Series) (Point (Lippincott Williams & Wilkins))

Yeah, that fits.

From reading and personal experience, I think a lot of people who are in 'mild panic mode' a lot of the time and can't concentrate find they have high breathing, are stuck in their heads, have tense necks - - - but don't notice it, because you only realise after you've 'opened out' that you were narrowly focused. They are "ungrounded".

Probably any exercise can help with that a bit. But something where you are consciously directed to shift your attention - like Qi Gong - can really expand your little world and loosen you off?

There's a great book called The Psychology of the Body, which is for massage therapists, but it went through different body tension patterns and their attentional focus, and it was very interesting how postural habits and character traits coincided. The massage therapy was therefore about leading the client's attention into their full body, more than just 'releasing muscle tension'. (I've never actually had the experience of that, but it sounded interesting.)