Sigmund Klein and the invention of Leg Curl?

Lifters today often take machine training for granted. From leg presses to leg extensions, its easy to think that such inventions have existed since the dawn of the gym age. This of course, is entirely wrong.

While machines have crept into nearly every gym these days, lifters in the past century had to be inventive when seeking to sculpt their bodies. This need for new ideas often resulted in the creation of machines and devices that have long since been forgotten. See for example, the Swingbell.

Regardless, new thinking was often a prerequisite for bodybuilding. A necessity which forced lifters to become thinkers in their own right. One such lifter named Sigmund Klein proved himself to be one of the more innovative individuals when he designed one of the first rudimentary leg curl devices in the early 1900s.

Created to develop the hamstring muscles, or as Klein labelled them, the biceps of the thigh, the below contraption was among one of the first attempts to fully isolate the muscles of the hamstrings. While lifters may question its safety, especially in light of the well balanced machines of today, there is no denying Klein’s innovativeness. Furthermore, that Klein advises readers on how to construct their own crude version of his device highlights the fact that many lifters operated out of makeshift gyms during this time. An interesting, if oft-forgotten fact.

Though it would be impossible to label Klein as the father of the Leg Curl machine, the below image nevertheless place’s Klein as an important originator in his own right.



Sigmund Klein, Super Physique Body-Building Bar-Bell Course (1931), 17.