History of the Leg Extension Machine

A mainstay in gyms across the globe, the leg extension is perhaps one of the most controversial machines amongst the lifting community, at least from the 1990s onward. For some it is a one way ticket to an ACL tear, while for others, it’s one of the most effective means of building up the iconic tear drop quad muscle.

That the machine’s existence causes such confusion undoubtedly gives us pause for thought. Who invented this machine? And why has it proved so enduring?

The Traditional Narrative


According to several scholars and even more dubious internet sites, the leg extension machine can be traced to Jack Lalanne. Readers of this website will undoubtedly remember Lalanne as the man who invented the Smith Machine, popularised the jumping jack and had a highly successful TV show to boot.

Well in the traditional narrative, a story which this website itself has been guilty of promulgating, Lalanne invented the leg extension sometime between the 1950s and 1960s. This in fact, is quite a plausible story. From later interviews Lalanne seems to have claimed credit for the invention, and given his promotion of the Smith Machine and also cable machines, it just seems likely that he invented this too. The problem for us is that it’s nigh on impossible to get the exact story of how it was invented by Lalanne or when he began to promote it. I tried in vain to track down the original patent and the best I could find was one from the 1970s!

As often happens however, a little more digging reveals a much longer story.

Enter the Iron Boots


These rather hideous beasts marked a short lived promotion from the 1940s onwards. Marketed as dumbbells for the feet, Iron boots, as detailed previously on this site, were promoted massively by Bob Hoffman of York Barbell. Though Sig Klein, an early proponent of the leg curl incidentally, was promoting a similar concept, it was Hoffman who kicked the Iron Boots hype machine into overdrive.

In 1943, Hoffman published A Guide to ‘Build Super Strength, Health and Development with the York Leg Developing Course’. Included amongst the rather grandiose claims of spectacularly increasing your muscle girth were illustrations of exercises one could do with the Iron Boots. Thanks to David Gentle’s excellent, and I do mean excellent, website on the history of physical culture, we have existing copies of the course available online.


Disregard the J.C. Higgins title in the photograph. As demonstrated by Ironcompany.com, which incidentally sells pristine York courses, we know that the above was a York original. Back to the message at hand, I’d like to point out exercise number one, which can only be described as a standing leg extension, albeit one that required much greater balance and coordination.

So Hoffman was the ideas guy and Lalanne simply created a machine version right? Again, it’s not that simple. We have to go even further back I’m afraid.

Dr. Gustav Zander And ‘Mechanotherapy’

Who and what am I right?

For those true anoraks amongst us, the name Gustav Zander will be somewhat recognisable. A Swedish doctor, inspired by the exercise systems of Per Henrick Ling, Zander believed that you could improve individual’s health and wellbeing through the use of machines or ‘mechanotherapy’ as he termed it. As an aside, it would be great to see personal trainers renamed as mechanotherapists. An idea for a different day perhaps.

Now what is truly important about Zander is that he created a series of quite frankly odd looking machines, which sought to exercise the body from every possible angle. You may start to guess where we’re going with this.

Though Zander’s machines are often a subject of ridicule nowadays online, he did help promote the first recognisable leg extension machine


Taken in 1892, the photograph above, kindly available from the Smithsonian, served as a ‘Knee and ankle flexion and extension machine.’ He also created a Knee Bending machine, shown below, which I suspect was more of a leg curl than anything else.


Combined these two machines were undoubtedly the precursors for any leg extension machine we use today. Why Zander is so pivotal to this story, and indeed American history, is that in 1876 Zander exhibited wares at the 1876 Centennial Exhibition in Philadelphia where his exercise machines won a gold medal. By 1906 he had established Institutes in 146 countries, including the United States. and by 1910 “ample numbers of Americans were familiar with the machines

Who popularised it?

This I’m afraid, is a much more difficult question. Though we can point towards Hoffman in the 1940s and his Iron Boots, it is hard to pinpoint which gym or manufacturer helped to push the leg extension into the mainstream. Certainly Arthur Jones and his Nautilus machines from the 1970s, which included a leg extension machine proved highly popular amongst the weightlifting community.

That being the case, we do know that the leg extension machine was used during Bodybuilding’s ‘Golden Age’ during the 1960s by the likes of Frank Zane, Arnold Schwarzenegger and Dave Draper amongst others. Interestingly, they seemed to use it as a means of warming up, rather than outright exercising their thighs, an approach now deemed by many to be the safest method of using the machines.

Wrapping Up

The history of the Leg Extension machine has, to date, largely stopped with Jack Lalanne. The purpose of the present article was not to denigrate in any way shape or form Lalann’e contribution to this exercise, but rather to highlight the longevity of this movement for weight trainers. Lalanne may well have invented the first recognisable machine but precedents were there in the form of Iron Boots and also Zander’s machines. That the movement has lasted for over a century at least, gives pause for thought about its efficacy.

That being the case, we’re still none the wiser regarding the promotion of the machine. If we follow the traditional narrative, we can say that beginning with Lalanne sometime in the 1950s, bodybuilders were introduced to the machine. Indeed many of our Golden Age bodybuilders from the 1960s used the leg extension on a regular basis. Perhaps, and again this is purely guesswork, we can look towards Arthur Jones’ work during the 1970s, which helped to popularise machine training in a much greater way.

If anyone has any information or can fill in the historical gaps please do get in touch!

As always… Happy Lifting!

P.S. We couldn’t have an article on the Leg Extension and not mention one of the most iconic and intense clips from Bodybuilding lore.

4 thoughts on “History of the Leg Extension Machine

Add yours

    1. You got very lucky with that one! Funnily a gym of mine had a similar machine and I always found it targeted the leg muscles better than more modern iterations.

      Hope you don’t mind but flicked through your gym photos there. The few dumbbells I have at home in case of emergency seem paltry in comparison! How long have you been building that home gym for? It beats a lot of the commercial ones near me!

Tell Me What You Think!

Up ↑

%d bloggers like this: