It may not apply to a crash with a big vertical component, but in a horizontal crash, such as a car accident, it pays to relax all muscles before impact.
easier said than done - particularly with the adrenaline pumping with the body reflexing because the brain has seen what's coming & is going bonkers.
you can see it happening, you realise how this might turn out, how will you fare...barely microseconds to take hold of the situation, decide & react accordingly....sphincter is doing 10 to the dozen;
5 cents / 50 cents / 5 cents / 50 cents.
"oh yes - & do try to relax"
thankyou dr. do-right.
spoken as always from the comfort of a big chair behind your desk, on terra firma & not strapped to a gravity-succomed, power-plant-deficient rotary-craft, plummetting to earth with only moments of an uncertain variety of thoughts pummelling your conciousness; am i going to walk away from this, am I going to crawl away from this, am I ever going to walk again, am I going to make it out of here alive, to childhood memories, loved ones & who knows what else.
sure I'll relax, when I am back home giving my wife & kids an extra hug & spending every breathing second living my life to the fullest.
i don't know that I am capable of over-riding the bodies basic desire to survive, flight or fight, will still result in an amount of stress/anxiety, & relaxation is possibly only going to be an after effect of a successful outcome.