The forces of nature can be impressive. The pound-for-pound strength of animals make humans mere weaklings. The strength of an adult chimpanzee, for instance, is at least three times that of an average grown man. A male gorilla can pull its whole 400-plus pounds of muscle upward using only one or two fingers!
The bite force of a spotted hyena is around 1000 pounds and designed to crush even elephant bones! The bite of a crocodile is a whopping 2000-plus pounds of pressure! That's like the weight of a medium-sized car! It can literally rip a gazelle in two.

Ounce-for-ounce, the strength of the rhinoceros beetle is unparalleled in all of nature's creatures including it's fellow insects. Its demonstration of strength is lifting objects about 800 times its own weight! That is like a grown man lifting a 60 ton army tank!

The strength and ferocity of ants are also legendary. I got bit by a large black ant once and its jaws literally pierced through the skin of my finger until it bled a few drops.

The spiked, jack-knife forelegs of the praying mantis is probably what makes it a popular insect for spectators. And yes, a praying mantis can and will (if it chooses to) use its spiny forelegs on your fingers if you try to pick it up the wrong way. 
Believe me, when I was inexperienced, I picked up a mantis by the back of its neck and it swung its long forelegs to grasp on to my fingers. Trust me, it is very sharp and very strong!

I have not heard of any study to measure the actual pressure that a mantid's foreleg can exert. I would imagine its comparable to a steel vice. It is something I may look into experimenting when I get the chance. I believe it can probably exceed the strength of crocodile jaws in proportion.

Nature does allow some mercy to potential prey. The lion, for instance, will first try to suffocate its prey before eating it by grasping the throat. A jaguar, whose jaw strength is the most powerful of big cats, can instantly kill its prey by biting through its skull, penetrating the brain!
 The mantid does not wait, however. It is a shocking sight to witness one eating a mammal such as a small mouse while still alive and suffering, held securely in its forelegs of steel.

The grip of death. Once the mantis kung-fu grip is applied to the prey it begins eating at once. It does not wait for its prey to die.

They say insects don't feel pain. They don't have the pain receptors that mammals and birds have. They may naturally and defensively react and retaliate when threatened. But insects can lose a limb from a fight and just walk away like nothing happened. The mantis can literally crush a grasshopper or cricket and break it in two and they will still move and wriggle.

But the mantid can also hunt small mice, birds, frogs, lizards, and sometimes snakes. As far as I know mammals and birds feel pain and being eaten alive by a hungry alien-like insect must be the most brutal torture. It is alot like the spotted hyena of Africa tearing into the underbelly of a wildebeest or zebra until it weakens, and the clan joins in for a feast while the prey cries out in agonizing pain for what seems like an eternity until its body goes into shock and finally dies.

We are normally accustomed to thinking insects are the prey of birds and lizards. So it is weird to see the reverse. But with an arsenal of two vice-like forelegs that strike at a blinding speed of 1/20 of a second the mantid can overcome prey many times heavier.
By Noy Ilao