Yes, if you are bodybuilding and rehabbing a knee injury only the ajustable kinds for rehab. For funtional strength,and power no! Why, logically when was a time that you did anything lifting your legs up while sitting on a seat. Absoultly, never. It the least functional machine there is. No purpose in trasfer to everyday activity. Thats my take on the leg extension. Even the name of the machine is wrong it should be called Knee flexion. Because thats what you are doing your not extending your legs your flexing at the knee.
In health,
Silas C.
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In Health,
Silas S Chen Exercise Specialist @ MorganStanely Fitness Center Mid-town NYC
Originally posted by fitone: Even the name of the machine is wrong it should be called Knee flexion. Because thats what you are doing your not extending your legs your flexing at the knee.
Wouldn't knee flexion be a leg curl and not a leg extension?
Danny
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Limitations are for people who have them.
Yes, knee flexion is a "leg curl". Quad contraction produces knee extension. In the anatomical context.
There are varying opinions about the utility of the leg extension, and I would say that most of them have to do with the question, "How specific does strengthening have to be to have functional consequences?" On one extreme, there is the "strength is strength" camp (where it doesn't really matter _how_ you strengthen, there will be benefits to your "functional strength"), and on the other extreme is the "every strength is specific" (where unless you're mimicking the exact "functional movement" during strengthening, you're not getting the full benefit of strength training). There aren't a whole lot of good answers, except that these extreme views are probably not very useful other than to examine the extreme poles of the argument themselves.
Are leg extensions better than nothing? Probably (though some might argue otherwise from a safety perspective). Are leg extensions functional? Perhaps not (but neither is a bench press, or a chin-up--unless you're a climber, or a military press, or a lateral raise or a front raise or a triceps kickback or a bent-over barbell or dumbell row) The range of human motions on a day to day basis for most people who don't have physical labour as part of their everyday occupation is quite minimal. Sit. Stand. Go from sitting to standing. Type. Write. Lift food/drink to mouth. Lie down. Get up from lying down. Walk. Occasionally chase a bus. Press gas pedal. Press brake pedal. Turn steering wheel. You get the point.
The answer to why or why not leg extension is almost entirely situational. I don't think there's a good answer for that question in the general context.
From a performance standpoint...they are basically GARBAGE. I think Alwyn Cosgrove even sited some research to me once that bascially said that not only is the strength you gain from leg extensions not applicable to "real life" activity....it may WEAKEN the actual performance of real-life leg/hip extension (i.e. running, jumping etc.)
From a rehab standpoint.....probably GARBAGE once again (perhaps Bill can site some research on this stance..). I'm SO tired of our athletic trainer prescribing leg extensions for our athletes coming off a knee injury!!! Read-up on any ACL rehab recommendations and they will ALWAYS emphasize the importance of #1 closed chain exercises and #2 Co-contraction of both quads and hamstring during exercise as being a vital part of knee rehab.
I was at the NSCA sport-specific conference and the scarey thing is that this exercise is listed on almost every ML Baseball conditionng program! Good one "experts"!!! [img]tongue.gif[/img]
One last thing...Bryan wrote....
Quote:
Go from sitting to standing. Type. Write. Lift food/drink to mouth. Lie down. Get up from lying down. Walk. Occasionally chase a bus. Press gas pedal. Press brake pedal. Turn steering wheel. You get the point.
Good points...all these movements are closed chain...kind of makes one think about the role if ANY open-chain exercises in the improvement of "functional" (I hate that term!!) activity huh? Also, just going from sitting to standing or getting up from a laying position requires the co-contraction that I mentioned...imagine sprinters, volleyball players and soccer players! [img]smile.gif[/img]
__________________
Robert dos Remedios, MA, CSCS,
HCC (Hartman-Cosgrove Certified)
Director of Speed, Strength & Conditioning
College of the Canyons, CA http://www.canyons.edu/departments/pe/strength
"NO CHAMPION HAS EVER ACHIEVED HIS OR HER GOAL WITHOUT SHOWING MORE DEDICATION THAN THE NEXT PERSON; MAKING MORE SACRIFICES THAN THE NEXT PERSON; WORKING HARDER, TRAINING, AND CONDITIONING HIM / HERSELF MORE THAN THE NEXT PERSON; ENJOYING HIS / HER FINAL GOAL MORE THAN THE NEXT PERSON"
Originally posted by dos: One last thing...Bryan wrote....
quote:Go from sitting to standing. Type. Write. Lift food/drink to mouth. Lie down. Get up from lying down. Walk. Occasionally chase a bus. Press gas pedal. Press brake pedal. Turn steering wheel. You get the point.
Good points...all these movements are closed chain...kind of makes one think about the role if ANY open-chain exercises in the improvement of "functional" [/quote]Actually, I think lifting food/drink to mouth is technically open chain with the free end. And well, maybe pressing the gas and brake pedal too--depending on whether you consider cycling to be an open or closed chain movement. I personally hate the terms closed and open chain. WTF is the kinetic chain?
Actually, I think lifting food/drink to mouth is technically open chain with the free end. And well, maybe pressing the gas and brake pedal too--depending on whether you consider cycling to be an open or closed chain movement. I personally hate the terms closed and open chain. WTF is the kinetic chain?
Bryan, I don't sweat the eating and drinking deal too much as this tends to be an EXCESS problem rather than something we need to train I was looking more at you examples of standing up, chasing a bus, getting up from a lying position etc.
I would, however, definately consider stepping on a brake pedal or even cycling as "closed-chain" for the simple reason that co-contraction occurs during these movements (thus making it more realistic). Take care! [img]smile.gif[/img]
__________________
Robert dos Remedios, MA, CSCS,
HCC (Hartman-Cosgrove Certified)
Director of Speed, Strength & Conditioning
College of the Canyons, CA http://www.canyons.edu/departments/pe/strength
"NO CHAMPION HAS EVER ACHIEVED HIS OR HER GOAL WITHOUT SHOWING MORE DEDICATION THAN THE NEXT PERSON; MAKING MORE SACRIFICES THAN THE NEXT PERSON; WORKING HARDER, TRAINING, AND CONDITIONING HIM / HERSELF MORE THAN THE NEXT PERSON; ENJOYING HIS / HER FINAL GOAL MORE THAN THE NEXT PERSON"
Brake pedal is definatly close chain but I don't know about bike peadling . I got an I idea why don't we start an open chain and close chain thread. [img]smile.gif[/img]
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In Health,
Silas S Chen Exercise Specialist @ MorganStanely Fitness Center Mid-town NYC
Based on Steindler's original and somewhat vague interpretation (contrary to popular opinion he did not coin the terminology), pressing on the the gas or brake pedal would not become closed-chain until the pedal is pressed to the floor (or near it) as the resistance would be insufficient. Bike pedalling would be open and closed depending on gear and point in the rotation of the pedal (more closed near the top and bottom of stroke if you're wearing clips). Also if your food or beverage of choice is extremely heavy, it may be considered a closed-chain activity.
Per Steindler,"the terminal joint meets with some considerable external resistance which prohibits or restrains its free motion." He also states that the resistance may eventually be overcome which is where some confusion is created with the his interpretation. Think of a standing cable push...light ones are open chain for the arm...heavy ones are closed chain??????
You also need to look a multiple chains...for instance in a step-up, while the foot typically meets a considerable resistance (the Earth via the step) the head and upper extremities are free moving and therefore open.
My point is that the discussion of whether an exercise is open or closed chain is pretty futile because the definition is open for some broad interpretation.
Is a jammer machine open or closed...yes on both counts depending on resistance...see what I mean.
As far as the leg extension goes...if doing a knee extension exercise where the distal segment does not meet with considerable resistance (often called open chain) improves some desired motor or structural quality in some case then it is useful. Just like every other exercise on the planet there will be a time and place. A big place for leg extensions...probably not. Would I put a healthy athlete (or an injured one) on a leg extension machine...doubt it.
If you're interested in wasting a great deal of time on what is mostly a useless topic the original definition is in Kinesiology of the Human Body Under Normal and Pathological Conditions. Springfield: IL, 1955.
Bill
P.S. In the words of the great Alwyn Cosgrove,"It's okay to break the rules as long as you know when you're breaking the rules"...I love that quote.
I'm not an expert, but I've had bad experience with leg extensions. Last year I incorporated leg extensions into my leg workout, and after a few months, I developed a sharp pain right underneath my right knee cap that would not go away. Once I elemintated knee extensions, the pain also went away. Maybe I was doing them wrong, but nonetheless, I don't do them anymore and no longer have knee pain.
Bill- I see how break pedal is close chain when actually stepping on the break. But, how does is cycling closed chain also? Its, not planted to the ground. Your still pedaling in air. Grant, yes your feet is on the pedal but, the pedal is no where near the ground. A fixed object. . Just striking up a thread not disagring or agreeing with you. .
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In Health,
Silas S Chen Exercise Specialist @ MorganStanely Fitness Center Mid-town NYC
closed chain does not require a fixed object...only a "considerable external resistance which prohibits or restrains its free motion".
A heavy leg press could be considered closed-chain, and it is not on the ground.
During pedalling a bike, the "closed-chain moment" is only for a fraction of a second at the very bottom and very top of the stroke where the muscle force changes from up to down and vice versa.
That's why it's such a pain in the ass (and useless) to classify exercises as closed or open chain as many exercises are both depending on loads and when loads are maximal. Walking is a cyclical closed and open chain activity, but not because of the ground being involved. If you were walking on a trampoline, the lower extremity chain doesn't "close" until all the elasticity is taken up when fully weighted the leg.
Would it be sensible to do knee flexion/extensions if you are trying to tone up your thighs, not to build strength necessarily? I do them besides stair climbers and things like it.
Heh. That largely depends on what you mean by "tone" (which is also a term that has little meaning for everyday people). Muscle tone refers to the resting tension in your muscle. Some people who have nervous system problems (like spinal cord injury) develop poor tone and their muscles may develop a sag. However, if you're healthy, your muscle tone is just fine.
Most people, when they talk about toning, simply want to lose body fat. The eternal myth that doing isolated movements, high repetitions and almost non-existent loads will produce firmer looking muscles is perhaps one of the most peristent and de-empowering strategies; and has probably been responsible for the abject failure of many women to change their appearance in any meaningful way (if they have wanted to change), due to its prevalence in female fitness "advice".
Flappy thighs and flappy triceps have mostly to do with fat, not muscle tone. Certainly, leg extensions, done properly and safely are probably better than doing nothing. But there's no reason why a woman can't squat or lunge either.
I too have stopped doing leg extentions or whatever we are calling them now...(I thought politicians were verbose)... I was doing them to square up my quads...my lower quads tapered. I was also "told" that it would help my sprained knee a few years back.
Perhaps it would be helpful for most of us to descibe the the effect of squat and lunge variations on muscle development...like front squats vs "regular" squats and lunges vs walking lunges
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Take care of your lawn
and
the grass will be greener on your side of the fence
OK, perhaps I am confusing them with something else, but what exactly is a leg extension? I want to make sure I am not doing them and doing something else. [img]smile.gif[/img]
Sit on apparatus with back against padded back support. Place front of lower leg under padded lever. Position knee articulation at same axis as lever fulcrum. Grasp handles to sides for support. Move lever forward by extending knees until leg are straight. Return lever to original position by bending knees. Repeat.
While it is not possible to 'spot-reduce' it is very possible to 'spot-build'. This being the case, Leg Extensions serve as a quadriceps isolation exercise...this would in fact play in a role in developing the quadriceps muscles (especially in terms of hypertrophy). I think Stephanie is referring to 'shape' when she says 'tone' so I assume she is only worried about the cosmetic effect of these isolated exercises. As far as cosmetics go, I think you would have a fight on your hands it you were to tell these guys to take leg extensions out of their workouts.....
For any other reason other than cosmetic ones I'll say it again...garbage.
P.S. why do people still refer to bodybuilding as a "sport"?!
__________________
Robert dos Remedios, MA, CSCS,
HCC (Hartman-Cosgrove Certified)
Director of Speed, Strength & Conditioning
College of the Canyons, CA http://www.canyons.edu/departments/pe/strength
"NO CHAMPION HAS EVER ACHIEVED HIS OR HER GOAL WITHOUT SHOWING MORE DEDICATION THAN THE NEXT PERSON; MAKING MORE SACRIFICES THAN THE NEXT PERSON; WORKING HARDER, TRAINING, AND CONDITIONING HIM / HERSELF MORE THAN THE NEXT PERSON; ENJOYING HIS / HER FINAL GOAL MORE THAN THE NEXT PERSON"
I got this definition of sport from the dictionary...check out #5...it almost seems fitting, huh?
Main Entry: 2sport
Function: noun
Date: 15th century
1 a : a source of diversion : RECREATION b : sexual play c (1) : physical activity engaged in for pleasure (2) : a particular activity (as an athletic game) so engaged in
2 a : PLEASANTRY, JEST b : often mean-spirited jesting : MOCKERY, DERISION
3 a : something tossed or driven about in or as if in play b : LAUGHINGSTOCK
4 a : SPORTSMAN b : a person considered with respect to living up to the ideals of sportsmanship <a good sport> <a poor sport> c : a companionable person
5 : an individual exhibiting a sudden deviation from type beyond the normal limits of individual variation usually as a result of mutation especially of somatic tissue
an individual exhibiting a sudden deviation from type beyond the normal limits of individual variation usually as a result of mutation especially of somatic tissue
Sounds more like what it takes to become "HARTMAN Certified"!!!
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