Hysterical Strength?

Whats the straightdope on this phenonomen, I’ve heard some anecdotal stories about it but on doing a little research on the subject the scientific concensus seems to be, “maybe”.

Any further info?


Certainly a combination of adrenalin and increased blood flow to the muscles will make a difference - that’s exactly how the human body is designed. I’d imagine that many anecdotal reports are exaggerated, though.

Here’s one thing I think ~could explain it: During normal use only a fraction of the fibers in a muscle bundle are “active”. The nervous system is constantly switching among active fibers so that they don’t all wear out (and it helps in a lot of other ways too). Maybe, during certain moments of stress, all of the fibers go active. The increase in potential strength would be significant.

But… The muscles are only one part of the system. The tendons, bones, joints, etc. would easily fail under significantly increased muscle tension.

That’s the explanation I vaguely recall hearing in the past.

Psst…pssst…Gamma Radiation.

You didn’t hear that from me.

Gaaaaammmmaaa raaadiaaaaation.

Don’t tell Mr Magee.

The adrenaline probably also prevents you from feeling the pain that normally tells your body that it’s reached its limits.

I vaguely recall something about some subconscious mental self-preservation mechanism being in place most of the time - we don’t use our full strength at all times, because we would tear ourselves apart in short order (just witness the laundry list of medical problems high level athletes wind up having). I also vaguely recall something about our jaw muscles being so strong and having so much leverage, we could technically crush our own teeth were it not for that mental block. However, in imminent danger, survival is way higher on the priority list than not hurting oneself too much - you can always heal later, as long as you’re not dead that is.

The dulling of pain signals by adrenaline works in that regard as well : you might very well be doing some serious muscle tearing damage to yourself, but you don’t feel it immediately. The morning after tends to suck, though.

And even if you are dead, your offspring might still survive. A lot of stories of hysterical strength are attributed to a mother doing something to save her kids.

The Straight Dope: SuperMom: Could a mother actually lift a car to save her child?

more Straight Dope: Everybody’s getting into the act: More tales of supernatural strength.

Yes this will play a part. When someone starts strength training, any strength gains in the first couple of weeks are almost purely due to your body learning to recruit more and more motor units.

In addition an antagonist muscle will activate when the agonist is contracting, for example your bicep will contract when you are straightening your arm, to prevent overextension of the joint.

Perhaps in moments of extreme stress these a combination of this mechanism switching off with large scale motor unit recuitment gives rise to an unexpected increase in strength.

Off topic, but pro powerlifts can suffer from a problem relating to this. They have trained to such a level that their muscles can contract with so much force they literaly rip themselves apart. Common sites are the tendon of the clavicular pectoral muscle and the distal head of the biceps tendon. Link

I heard somewhere - maybe Ken Johnson’s commentary on the Incredible Hulk pilot? - that you don’t always need the strength to lift 1 or 2 tonnes to “lift” a car of an injured person if the circumstances are right, because if part of the car is resting on the ground - the case if it’s been flipped over during an accident - this can act like a pivot, and you basically have a lever.

When filming the Incredible Hulk (TV series) pilot, there was a sequence of a woman lifting a car to rescue her child after an accident; Kenneth Johnson says that the put an inflatable bag under the remote side of the car and lifted it a bit so that the actress only had to swivel the car.

So that might play a part too and explain why bones don’t break etc.

An article I read recently (perhaps it was the 2/1 edition of Time, but I gave that away and don’t have it any more), stated that it is possible for a man to lift up the front end of an auto, as recently happened, but he has to have the strength to begin with. The person who did the lifting was a weightlifter, and, although he never lifted that much before, with the additional adrenalin surge, he was able to do so.

Even without an adrenaline surge, I’ve heard that Andre the Giant once changed a tire for a stranded motorist without using a jack. Then again, the car was a Beetle, and Andre the Giant probably isn’t the best example to use when discussing human strength.

I dunno… he actually might be typical of a 2.1 meter human being after intensive strength training…

But then, there are very few humans over 2 meters tall, let alone athletes of that height and category.