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Arthur’s Misadventures with Acceleration On the Human Knee
Oct
25
2012

Arthur’s Misadventures with Acceleration On the Human Knee

31 comments written by Ken Hutchins

Arthur’s Misadventures with Acceleration On the Human Knee

by Ken Hutchins

Slamming Into Lockout

In 1982, Arthur Jones created much excitement with the Nautilus DuoSquat machine. He motivated Jim Flanagan and several other large men to experiment with high-repetition sets of 50 repetitions per leg. Putting the nonsense of such repetition schemes aside, I was more appalled with the violence Arthur permitted in form.

Arthur decreed that the seat be set so that the subject could straighten each of his legs under the selected load. As Arthur pushed Jim Flanagan and others through their DuoSquat routines in the prototype shop, they habitually fired out of every stretched position and slammed into every lockout. As a result of Arthur’s insistence in the gym, these subjects (employees) echoed his dictum to “completely straighten the legs” to Nautilus customers.

At Nautilus Seminars I instructed customers to set the seat so that lockout was impossible.

I established lockout as a serious liability concern. I also declared that lockout was discordant with Nautilus Philosophy. It unloaded the desired musculature, excessively compressed the spine, excessively loaded the neck musculature, and was unduly dangerous.

Arthur’s closer henchmen reported to him that I was countermanding his protocol regarding the DuoSquat. I did not fear Arthur’s wrath, because I was his only willing and eligible pigeon slated for guard duty at the Nautilus-funded Osteoporosis Research Study.

As a result, Jim Flanagan orchestrated my trip to the woodshed, so to speak. As Jim and others observed from a distance, Arthur patiently explained and justified his recommended protocol for the DuoSquat. This meeting occurred just before commencement of the Osteoporosis Study in late 1982. I now surmise that it was crucially important that I be on board with Nautilus marketing of the DuoSquat if it were to be a financial success.

I admit that I did learn from Arthur during this mild cross examination. He showed me how he had designed the cam radius—reduced only so far (force increased) as to not exceed bone integrity. He calculated a safety margin and stayed on the safe side of that margin. (1,174#?)

Arthur also explained that he had designed the seat tilt at such an angle (approximately 30 degrees) to the movement-arm line of force so that approximately 1/2 of the force (Sine 30 degrees) was supported through the pelvis and backpad, not the spine, shoulders, and shoulder pads. This I had not considered.

I then presented Arthur with my reservations of lockout. I also raised a question: “Are we using the machine to defeat the machine or to fatigue the muscle?” [Note that this was my first intellectual consideration and expression of the Assumed vs Real Objective Argument.] He then threw a rhetorical question at me: “Ken, do you realize, upon reaching lockout, that the force doesn’t suddenly jump from the muscles onto the bones?  The bones are supporting the load throughout the movement, not just suddenly at lockout?”

I replied that I had not considered the possibility that such a fear was lurking in my mind and affecting my bias. And I promised to reflect on the matter for a while to examine his protocol recommendations in light of this possibly irrational fear as well as his other points recently shared.

Indeed, The Force Does Jump From the Muscles Onto the Bones at Lockout!

 I left for the Osteoporosis Project in October 1982. After unsuccessfully incorporating the DuoSquat into the workouts for our study subjects for 6-8 months I wrote Arthur the following memo sometime in mid-1983:

 Arthur,

    Approximately a year ago, we discussed my reservations regarding the safety of lockout during the performance of the DuoSquat. You speculated that my bias was the result of an unacknowledged and irrational assumption. The supposed fear: the resistance force suddenly jumps from the muscles onto the bones at lockout.

    Although this notion may or may not have been lurking beneath my conscious process, you certainly planted the seed for its complete fruition. Note that five sources of force converge at lockout:

I

    Disconnect the chain from the movement arms on the Duo Squat. Then place the subject as you dictate—seat so close that he can just barely lockout his legs against the frame of the machine. Here the subject encounters maximum force from body compression, movement arm flexion, pad compression, etc. Denote this machine force.

II

    Once reconnected, the negative cam is at its smallest radius, hence its greatest resistance provision at lockout. Denote this cam force.

III

    At lockout the quadriceps are no longer effecting knee rotation. They exert a force encouraging translational movement of the tibia into the femur. Denote this quad force.

IV

    At lockout the hamstrings are no longer effecting hip rotation. They exert a force encouraging translational movement of the tibia into the femur. Denote this hamstrings force.

V

    The screw-home property of the knee results in maximum stability at lockout. This occurs in part because the cruciate ligaments contract as they twist on one another akin to twisting the opposite ends of a dish rag. This tightly approximates the ends of the tibia and femur. But if the knees are violently extended, this contraction is so forceful that the cruciates are commonly avulsed, carrying sizable chunks of their moorings with them. Denote this cruciate force.

    As a result of lockout in the DuoSquat, five forces promoting translational shortening of the body converge at lockout. Therefore—in effect—these forces do suddenly jump from the muscles onto the bones at lockout.

                                                                Sincerely,

                                                                Ken Hutchins

As usual, no reply came from Arthur. But his reaction to my letter was unmistakable at the next Nautilus Seminar. He and his henchmen—other than me—began to warn customers to set the seat as I had detailed. A protocol involving lockout was no longer permissible or deemed safe. No one mentioned or dared to remember that it was once recommended.

Excessive Sanitation

My letter to Arthur was much too sanitized. It did not mention or account for acceleration forces resulting from the recklessly ballistic behavior that I observed by Arthur’s closest associates while using the DuoSquat.

Acceleration was the Big One. Acceleration forces accounted for the greatest threat to the human body during the DuoSquat. And acceleration accounts for the greatest force threat generated during all human movement, even that during a weightless environment. By this I do not mean to entirely distract the reader away from the points I belabored in my letter to Arthur. In fact, those issues so mentioned are more glaringly egregious because of the acceleration!

I did not mention acceleration in the letter, because I intended a purely static analysis, and because I knew that the subject of acceleration would cause tremendous defensiveness on the part of Arthur. He already considered himself extremely sensitive to acceleration effects, while I saw through his weakness on the subject.

The effects of acceleration indicate that subjects encounter excessive force merely by slamming their knees into lockout when under no external load. The wide-spread ignorance of this fact often engenders false critical analysis of the proper design and use of all exercise equipment. Specific to this discussion are exercises involving the knees: knee extension, knee flexion, and leg press or squat.

As I have belabored for over 20 years, that without the speed being controlled consistently at excursions of 8-12 seconds, camming, body placement, load points, attitude, alignment, and other factors are of secondary consequence.

{ 31 comments… read them below or add one }

avatar Joshua Trentine October 25, 2012 at 4:18 pm

This article begins a series of discussions about some vintage Nautilus equipment and also some of what is being called the current state of the art. We’ll discuss fundamental misunderstandings that have taken the exercise equipment business the wrong direction.

Look for a follow-up on the DuoSquat next week and the Nautilus OME sometime after.

This discussion about the knee came from online comments about the knee, biomechanics, muscle joint function and equipment design. Ken has tackled most of these things 15 to 20 years ago, but I think this article, The Shear Forces Shear Nonsense article, and past equipment design articles set a precedence.

Joshua

Joshua

Reply

avatar Joshua Trentine October 25, 2012 at 4:19 pm

This article begins a series of discussions about some vintage Nautilus equipment and also some of what is being called the current state of the art. We’ll discuss fundamental misunderstandings that have taken the exercise equipment business the wrong direction.

Look for a follow-up on the DuoSquat next week and the Nautilus OME sometime after.

The discussion to present these articles came from some uninformed online comments about the knee, biomechanics, muscle joint function and equipment design. Ken has tackled most of these things 15 to 20 years ago, but I think this article, The Shear Forces -Shear Nonsense article, and past equipment design articles set a precedence.

Joshua

Reply

avatar gus diamantopoulos October 25, 2012 at 5:14 pm

Ken,

Excellent post.

This is something that should be read by everyone who participates in any fitness endeavour, particularly those involved in strength exercise.

gus

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avatar Jason October 25, 2012 at 7:17 pm

I see the insanity still continues. RenEx continues to attack and belittle anything and everything that isn’t RenEx. Now you even stoop so low as to ridicule and attack a dead man and his 30 year old, out of production machine that very few people still have or use. Ridiculous nonsense.

All this is nothing more than Ken’s continuing vendetta against Arthur and his ongoing attempt to destroy the man’s reputation, and to try to convince the world that he (Ken) is much smarter than Arthur and a more brilliant machine designer. Sick and sad.

Ken needs psychological counseling.

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avatar Joshua Trentine October 25, 2012 at 8:47 pm

You might want to actually read the article.

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avatar Joshua Trentine October 25, 2012 at 8:58 pm

Ad hominem

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avatar Craig October 25, 2012 at 7:19 pm

You wouldn’t happen to have any old video from “back in the day” showing the improper execution of these exercises?

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avatar Joshua Trentine October 25, 2012 at 8:45 pm
avatar Ben Tucker November 5, 2012 at 10:02 pm

Hey! It’s Boyer off the gear! Proof that HIT doesn’t work!
Guess Ray intercepted his shipment;)

I’m right there with the good Dr… That’s some scary lock-out. Watch as the knee bounces about a 1/4″ the wrong way. Anyone else notice that quad offloading?

And, an excellent demo on how to properly engage Val Salva…
I love hydraulics!

Reply

avatar Russ October 25, 2012 at 10:07 pm

I don’t see Ken’s comments as a attack on Arthur but a compliment to the ground work Arthur did. A famous mathmatician once commented on people saying how brilliant he was—-“It was easy I stood on the shoulders of giants”
If I remember correctly it was Newton. The work is what is the most important thing. The advancement of knowledge and study. I knew Arthur not as completely as Ken but well. Tho I had bought over the years about 200k worth of nautilus equipment including the Duo Squat and some Omni Machines.
I like the range of motion of the Squat but it was rough on the knees. we used the inflimetric bar thus reducing the range of motion and enjoyed it better than straight alternating legs/

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avatar Joshua Trentine October 25, 2012 at 10:29 pm

Russ,

It’s all about discovery.

And of course RenEx doesn’t exist without Arthur’s contributions.

Joshua

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avatar Anthony October 25, 2012 at 11:49 pm

Hi, my name is RenEx.

(see image)

http://i.imgur.com/kHbY3.jpg

Reply

avatar Joshua Trentine October 26, 2012 at 1:22 am

Anthony,

I’m embarrassed for you at this point.

Joshua

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avatar Doug McGuff, MD October 26, 2012 at 1:08 am

Josh,

That youtube clip made my cruciates whimper.

Reply

avatar Joshua Trentine October 26, 2012 at 1:29 am

whimpering cruciates are never good.

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avatar gus diamantopoulos October 26, 2012 at 9:10 am

There is no person I can think of who respected Arthur more than Ken Hutchins.

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avatar Dean Curtis October 26, 2012 at 12:16 pm

Agreed Gus. Back in the day I have spoken with Ken and Mike Mentzer on Arthur. As Mentzer stated, “Even Jones, with his great intellect…”.

The point is similar to someone today studying quantum theory and acknowledging that the giant Newton did not know EVERYTHING. We are grateful for the geniuses of our past, but even they had SOME things wrong. The duty of each generation is to keep what is true, investigate what is still not known or unclear, to build on more truth for the next generation. In my field, computer science, a generation is about 18 months, continual upheavals 🙁

Everyone think about this: Ken is educating this generation in the Renex team. Watch some of the videos, Gus and the gang questioned Ken on some things; intimidating, annoying, but necessary. True leaders do not mind the questions.

Whether you agree with a specific point or not, critique but do not criticize or ad hominem. Join in the research and exploration. You might find yourself having a bit of fun in the process!

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avatar Joshua Trentine October 26, 2012 at 12:18 pm

Dean,

This is a really great post.

Joshua

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avatar Scott Springston November 5, 2012 at 11:34 am

Everyone think about this: Ken is educating this generation in the Renex team. Watch some of the videos, Gus and the gang questioned Ken on some things; intimidating, annoying, but necessary. True leaders do not mind the questions.

==Scott==
Very true, a true leader does not shirk away from questions. Arthur was a genius but not everything he said or did was right. I think Ken fits this same category of genius. It will be interesting to see what fault if any can be found in Kens work years from now when we can look back at it all with a new perspective.

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avatar Donnie Hunt October 26, 2012 at 9:49 pm

I really enjoy learning about the history of Arthur and Nautilus. I still vaguely remember being with my dad at the local Nautilus facility here when I was very young. I remembering wondering what all the parts on the machines were for later in my high school’s workout room. My dad happened upon a copy of Dr. Darden’s, The Nautilus Book in the public library one night. 1985 edition I believe? After reading the book I had a very different view of this thing called strength traning / bodybuilding. I think this was the first time I learned some about Ken Hutchins. There was a chapter about the Osteoperosis study. If I remember correctly I had also already been reading some of Mike Mentzer’s articles. I want to say guys keep the great, technical information coming.

I’m curious. When Arthur first started designing and building the machines, were there single joint, rotary and compound both from the get go? The reason I ask is because from reading some of his writings and watching the David Letterman interview on Youtube, I got the impression that maybe the compound machines came along later.

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avatar Joshua Trentine October 26, 2012 at 10:39 pm

Donnie,

This is a really great story. I got my first Nautilus workout in 1985, my high school had nearly every piece, we trained M,W,F….I added much size.

Like you I was so intrigued by the size of the machines, the gears, the chain….who would have thought someday we’d be producing our own.

I’ll pass this comment on to Ken to answer the rest.

Thanks for taking the time,
Joshua

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avatar Joshua Trentine October 28, 2012 at 3:23 am

Donnie,

I’ll post a new blog with Ken’s response on Monday.

Joshua

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avatar Donnie Hunt October 28, 2012 at 4:00 am

Thanks alot Joshua. I don’t know what my gains were back then. I do recall being able to slightly lift the stack on the Leg Extension, eventually. Being able to add some weight to chins and dips using the Multi-station. Back then a big concern of mine was demonstrating strength, lol. I’ve never been a big guy. I’m about 5’10. Not much bodyfat. The most I’ve ever weighed was about 170 I believe. There was a DuoSquat there, maybe about 10 or 11 Nautilus machines altogether. There were at least three different places here in Marion that had a decent amount of Nautilus Machines back around this time period.

Reply

avatar Joshua Trentine October 29, 2012 at 3:27 pm

A complete answer to your question is now up as of 10/29/12.

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avatar Martin October 27, 2012 at 4:51 pm

Hi everybody,I am a total beginner to exercise in a decent shape(5.11-180 pounds 37 years) and would like to start your super slow system.Would it be wise to start using 10/10 speed right from the start with only 1 set to failure or should I start with more sets, faster speed and stop shy of failure?I only have access to squat,bench press and chin-up in my friend’s garage.I will never ever pay for any damn gym.

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avatar Joshua Trentine October 28, 2012 at 3:20 am

Martin,

Thanks for your question.

The best way to get the nuts and bolts of this protocol is with The Renaissance of Exercise book by Ken Hutchins.

http://www.renaissanceexercise.com/webstore/

In this book you’ll will see the evolution of the speed of motion recommendations and where best applied and where it might be tweaked.

Joshua

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avatar Kevin September 22, 2013 at 8:08 pm

If I may, have a question about the Nautilus DuoSquat machine. I agree with your protocol about moving the seat forward so that lockout is impossible. I was wondering if in your research, anyone tried to adjust the two “bolts”, one on each movement arm, so that even that slightly greater range of movement would be allowed and thus work more of the muscles involved?
Thanks. Sept. 22. 2013

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avatar Joshua Trentine September 27, 2013 at 10:01 am

yes, that is the correct set up

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avatar darcy February 17, 2014 at 1:49 pm

i love the duo squat , but to make the movement easy on the knees ,i put my feet very high on foot platform , i putt put a 2in. round wood rod, at the top of the platform behind the platform ,to keep the foot angel ,so i am pushing with the heal of foot , just use a longer bolt at the top ,put the 2 in. round rod 3 in. above the top platform bolt and tighten works great. no knee disconvert or pain at all. allso adjust the range limiter bolts so you dont use the very last part of cam gets to heavy at that point.my toes are at the very top of platform . i am 58 and understand moust of what arther jones taught.

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avatar James Jordan September 23, 2015 at 8:34 am

Is the duosqaut a safe machine to use? I just bought one actually and after reading this article I’m having second thoughts? Did I make a mistake? If it is safe, can you please provide me with the exact procedure to safely use this machine? I also read somewhere else the machine causes compression of the spine which doesn’t sound good. This was in some internet forum so I don’t think it was expert opinion. There are also many many forum comments about how magnificent this machine is. I’m confused. Thanks.

James

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avatar paul loughran October 5, 2022 at 5:00 am

Hello All, Im looking for one of these machines to buy.
Anyone willing to sell?

please email me

Best Wishes Paul

Reply

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