Really, I think I've always watched contortionists do the trick, and thought "well, they need that on a lot tighter, don't they?!"
Well, yes... they do.
I really didn't want to be called on stage, and I thought that I was sending "I'm looking elsewhere so please don't call on me..." vibes, but I guess they didn't work.
Is it just me, or is the idea of randomly picking the guy in the crowd who appreciates tight lacing on corsets perhaps the wrong choice for tightening a straightjacket?
Well... yes and no. And probably mostly no, in retrospect.
So, why are they always able to get out of those straightjackets so easily? I'm writing it off to a combination of design and technique.
The above straightjacket is somewhat similar to what the guy I saw today was using, with perhaps an addition of an extra strap. By no means identical, perhaps, but it illustrates the same general weaknesses of the basic style.
Note the leather straps, which imply strength to the crowd. Impressive looking, perhaps, but the problem is, none of the above straps are *REALLY* tight. They're tightened to their final eyehole, sure... but consider the available slack "built in" to the particular designs by not having additional eyeholes. Clearly, there are straightjackets designed for psych patients, and straightjackets designed for contortionists!
The result of the above design? More freedom to shift the arms and to get one arm over the head, which allows the second one to get over the head, which then allows the escape, as I will explain later on.
Indeed, thin leather straps are easier to get out of, in that they are less wide and actually have less bonded resistance with the cloth of the straightjacket than more "simple", less "strong" looking cloth designs, such as the one below...
So many more restraints, with increased surface bonding, and a lot more of an ability to tighten the straps not based on eyeholes, but in a completely adjustable way.
What's more, highly functional straightjacket designs have this feature up front.
Funny how one simple sewn strip of cloth can make getting out of a straightjacket so much more difficult, isn't it?! Try getting your arm over your head with one of those... much harder, I'm sure!
One of the more "interesting" straps, as you might suspect, is the one that goes from the rear of the straightjacket, under the groin, and back upon itself to tighten again in the back.
This, surprisingly enough, *WAS* completely adjustable to maximum tightness, and didn't use eyeholes and a buckle. The line tightened upon itself, basically, with teeth.
And, of course, being that the performer probably goes out of his way to pick someone in the audience who looks like they're going to really tighten the straightjacket thoroughly -- and yes, of course, I did, until he did his requisite joke regarding how tightly I was doing the groin strap -- well, it seems to me that there is a clear reason for doing so!
In short, increased believability of the difficulty of the act, combined with increased ease of escape, to the point where they probably have to slow themselves down and put on a big show of "struggling" to get out.
But in reality, it's gotta be easy. The more tightened the bottom clasp is, the closer it will be after being fully tightened to the front bottom side of the straightjacket, where a performer who successfully gets an arm over his head can get a hand into the suit, reach down, and release the bottom clasp on the straightjacket. It would actually be a *LOT* easier to release a tooth clasp singlehanded than an eyehole-and-buckle strap, especially one that's firmly affixed to the lower back, where the contortionist couldn't reach it.
So, yeah... design and technique... and if you pick someone from the crowd you think will suitably convince the crowd that there's a meaningful challenge to the act, even better. And the better you are at the techniques involved, the more advanced of a straghtjacket design you can handle, I'm sure.
But really... a straightjacket is a straightjacket to most people. Who's paying attention?!