Unlike most boys in his time at the age of 15, Sig Klein wasn’t inspired by a strongman act in a circus, but after reading Physical Culture & Strength magazines back in the 1900’s. Some say he was also inspired to start training by his father, who was a strong and muscular man. He began his training at the age of 15 and bought his first barbell in 1919 and was a disciple of Maxick. Apart from being a bodybuilder, an innovator (he invented the Feet Press Machine, The Iron Boot and the In-Klein Board), Siegmund Klein was also very accomplished in hand balancing and tumbling.
Sig Klein said that the Tiger Bend should be practiced by all athletes who wish to excel in the Two Arm Press lift. Although it’s an excellent exercise, you should become good at hand stand before commencing this exercise.
These exercises along with various barbell workouts are explained in his “Super Physique: Bodybuilding Barbell Course” book.
I read an article where Sig Klein said he thought he had invented the iron boot/shoe, but later came across some German physical culture magazines from the 1870s and found they were advertised there.
As the saying goes, great minds think alike. He could have invented it, only to find others had done so previously. The history of duplicate inventions is quite interesting.