Are Leg Extensions bad for you?

Gunzz160 · 03-27-2007, 05:35 PM

I have heard this time and time again by people saying that you can develope water around your knee joint and that they arn't good for you. Any truth to this?

NeilPearson · 03-27-2007, 05:38 PM

I think that is how I herniated a disk in my back

AKIRA · 03-27-2007, 06:20 PM

To tell you the truth, I was thinking of the biomechanics of the knee a few days ago and I cant quite picture the movement of the knee being different from a squat.

Actually, the only difference I can think of is that the weight is placed on the top of the shins instead of directly above the knee.

If this is a good start in understanding the difference in the extension/flexion of the knee, let me know.

P? Cow?

Did Cow get slaughtered? Where the fuck has he been?

Duncans Donuts · 03-27-2007, 06:30 PM

doing leg extensions, don't let the resistance go the entire 90 degrees from full extension (i do 4/5 of the total range of motion) - this keeps tension on the quad group as well as prevents higher shearing force on the knees.

no leg extensions are not bad for you

Goodfella9783 · 03-27-2007, 06:32 PM

Quote:

Originally Posted by Duncans Donuts

doing leg extensions, don't let the resistance go the entire 90 degrees from full extension (i do 4/5 of the total range of motion) - this keeps tension on the quad group as well as prevents higher shearing force on the knees.

no leg extensions are not bad for you

So basically don't extend your leg completely straight?

KelJu · 03-27-2007, 06:35 PM

Quote:

Originally Posted by Duncans Donuts

doing leg extensions, don't let the resistance go the entire 90 degrees from full extension (i do 4/5 of the total range of motion) - this keeps tension on the quad group as well as prevents higher shearing force on the knees.

no leg extensions are not bad for you

That makes a lot of sense actually. I might start throwing them back in my training every now and then, but only go 4/5 the way.

I would also like to get others opinion on this.

Duncans Donuts · 03-27-2007, 06:38 PM

i mean away from leg extension, when the knees are flexed. don't allow the shins to go further than a 90 degree angle relative to thighs.

if you let your knees continue to flex, you are removing tension from the thighs. that is why you do 4/5 of the way, to prevent shearing and maintain tension.

Goodfella9783 · 03-27-2007, 07:14 PM

That may be hard to do considering some machines may start past that 90 degree angle. At least the ones on home gyms that aren't adjustable. I'm going to go check out the extension part of my bench real quick.

**CowPimp** · 03-27-2007, 09:06 PM

I've read far too many suggestions from fitness professionals suggesting you have to make various alterations (Though they don't always agree entirely) to the movement in order to prevent unwanted shearing forces on the knee. I just avoid it because there are plenty of other exercises out there that are less controversial.

**P-funk** · 03-28-2007, 01:07 AM

Quote:

Originally Posted by CowPimp

I've read far too many suggestions from fitness professionals suggesting you have to make various alterations (Though they don't always agree entirely) to the movement in order to prevent unwanted shearing forces on the knee. I just avoid it because there are plenty of other exercises out there that are less controversial.

same.

AKIRA · 03-28-2007, 01:21 AM

Quote:

Originally Posted by Goodfella9783

That may be hard to do considering some machines may start past that 90 degree angle. At least the ones on home gyms that aren't adjustable. I'm going to go check out the extension part of my bench real quick.

That is true. Every leg extension machine begins before 90 degrees.

I really want to attack this shit. I want to know, in its simplest form why it could be detrimental.

Expect newbie questions to simplify the result...

slip · 03-28-2007, 01:23 AM

Havent had any noticeable bad sensations in my knees from them, but definately see the potential for Bad Things.

On a related note, started using more weight on the seated hamstring curl machine (up to 220lb) for 10 reps and have a strange sensation in my knees afterwards. Definately some uncool forces going through them at that weight.

blueboy75 · 03-28-2007, 01:46 AM

I do single leg extensions as a light warm-up before commencing my squats - feels pretty good for me.

**P-funk** · 03-28-2007, 07:59 AM

Quote:

Originally Posted by AKIRA

That is true. Every leg extension machine begins before 90 degrees.

I really want to attack this shit. I want to know, in its simplest form why it could be detrimental.

Expect newbie questions to simplify the result...

an open chain movement of that nature (ie underload) can lead to greater amounts of shear force as it pushes the patella back into the joint. Hence the reason people say start the life at an angle >90 degrees.

AKIRA · 03-28-2007, 10:11 AM

I suppose you can adjust the machine to make it start at or passed 9 0 degrees, but the ROM would be shortened. And if the ROM is shortened, then the workout isnt as effective.

I personally havent ever had knee problems on the machine, but thats not why I dont do them. I dont do them cuz of the warnings and the boredom.

I always felt my legs;s muscles near the knee being worked and sore. Never anywhere up my leg near my torso.

ponyboy · 03-28-2007, 10:16 AM

Quote:

Originally Posted by CowPimp

I've read far too many suggestions from fitness professionals suggesting you have to make various alterations (Though they don't always agree entirely) to the movement in order to prevent unwanted shearing forces on the knee. I just avoid it because there are plenty of other exercises out there that are less controversial.

I would agree with this. I haven't done one in years.

Duncans Donuts · 03-28-2007, 02:58 PM

Quote:

Originally Posted by AKIRA

I suppose you can adjust the machine to make it start at or passed 9 0 degrees, but the ROM would be shortened. And if the ROM is shortened, then the workout isnt as effective.

To the first point:

with most leg extension machines, 100% of the load is imposed when the leg is fully extended. 0% of the load is imposed on muscle at 90 degree flexion. Therefore shortening the ROM will actualy increase tension time and make the workout MORE effective by not allowing for any relief of tension.

**Dale Mabry** · 03-28-2007, 04:09 PM

Quote:

Originally Posted by AKIRA

To tell you the truth, I was thinking of the biomechanics of the knee a few days ago and I cant quite picture the movement of the knee being different from a squat.

Actually, the only difference I can think of is that the weight is placed on the top of the shins instead of directly above the knee.

If this is a good start in understanding the difference in the extension/flexion of the knee, let me know.

The difference is in hip flexion. At the bottom of the squat, your hip is flexed more than in a seated leg extension, this puts the rectus femoris in a shortened state. Since it is biarticulate, you have to consider motion at both joints.

Phred · 03-28-2007, 04:38 PM

Quote:

Originally Posted by Dale Mabry

The difference is in hip flexion. At the bottom of the squat, your hip is flexed more than in a seated leg extension, this puts the rectus femoris in a shortened state. Since it is biarticulate, you have to consider motion at both joints.

yea ...what he said.

VILBAUGH · 03-28-2007, 06:45 PM

the answer is simple;
the movement on the "leg extension" is not functional.

Every time you get off a chair, you squat....very functional.

Duncans Donuts · 03-28-2007, 10:36 PM

Quote:

Originally Posted by VILBAUGH

the answer is simple;
the movement on the "leg extension" is not functional.

Every time you get off a chair, you squat....very functional.

Doing leg extensions will improve your general strength in the quad femoris group, which will help you in the real world with things that require general leg strength. Period. Functional is a buzz word. Bench presses aren't functional. Seated presses aren't functional. Silly.

Nate K · 03-28-2007, 11:26 PM

Why would you want to do seated presses?

**P-funk** · 03-28-2007, 11:48 PM

Quote:

Originally Posted by Nate K

Why would you want to do seated presses?

so that you don't have to stand up.

slip · 03-29-2007, 06:50 AM

Quote:

Originally Posted by Nate K

Why would you want to do seated presses?

Why would you want to do standing presses?

VILBAUGH · 03-29-2007, 07:15 PM

Why would you want to do standing presses?

Anytime I ever lift a load overhead while living life outside the gym is in the standing position, so why sit down?

what if you had to do more than 4-20 reps? say lifting people or sand bags or boxes of bannanas or anything, Im pretty sure you'd want know how to lift it while standing and maybe have a little support from your hips while doing it....

VILBAUGH · 03-29-2007, 07:30 PM

bench press is definitly functional, your pushing a load off and away from your body, if it were any other situation, like being pinned, I couldn't see myself bringing the load behind my head for a "tricep extension", that to me would be silly.

however you are right about one thing, seated pesses are not functional.

serious powerlifters will pin the bottom of the stack on a leg extension apparatus and achieve many reps having never used it.
only squatting.

slip · 03-30-2007, 12:44 AM

Quote:

Originally Posted by VILBAUGH

Why would you want to do standing presses?

Anytime I ever lift a load overhead while living life outside the gym is in the standing position, so why sit down?

what if you had to do more than 4-20 reps? say lifting people or sand bags or boxes of bannanas or anything, Im pretty sure you'd want know how to lift it while standing and maybe have a little support from your hips while doing it....

I was merely making a point that there are many ways to do things, and many reasons to do things different ways.

Duncans Donuts · 03-30-2007, 12:57 AM

Quote:

Originally Posted by VILBAUGH

bench press is definitly functional, your pushing a load off and away from your body, if it were any other situation, like being pinned, I couldn't see myself bringing the load behind my head for a "tricep extension", that to me would be silly.

however you are right about one thing, seated pesses are not functional.

serious powerlifters will pin the bottom of the stack on a leg extension apparatus and achieve many reps having never used it.
only squatting.

what do i care what powerlifters do?

leg extensions increase cross-sectional space of muscle, thus increasing force output, thus increasing strength.

squats do the same thing but through more degrees of freedom.

i would pick squats over leg extensions any day, but i wouldn't throw the baby out with the bathwater. leg extensions are safe and have great benefit. functional is a buzz word. laying on your back and bench pressing is *NOT* functional to any activity you might encounter in every day life.

Duncans Donuts · 03-30-2007, 12:59 AM

Quote:

Originally Posted by VILBAUGH

Why would you want to do standing presses?

Anytime I ever lift a load overhead while living life outside the gym is in the standing position, so why sit down?

what if you had to do more than 4-20 reps? say lifting people or sand bags or boxes of bannanas or anything, Im pretty sure you'd want know how to lift it while standing and maybe have a little support from your hips while doing it....

to increase muscle size in your DELTOIDS, clearly.

don't dismiss exercises because they don't fit your view of training. why would i be lifting people or sand bags or boxes of bananas?? if that were a part of my job, I certainly wouldn't compound the overuse of those muscles by incorporating MORE standing lifts in my routine.

03-27-2007, 05:35 PM	#1
Gunzz160 Registered User Join Date: Oct 2005 Posts: 11	Are Leg Extensions bad for you? I have heard this time and time again by people saying that you can develope water around your knee joint and that they arn't good for you. Any truth to this?

03-27-2007, 06:20 PM	#3
AKIRA I am Rollo Tomassee.. Elite Member Join Date: Jul 2005 Location: Outside the box Posts: 8,787 Photos: 3	To tell you the truth, I was thinking of the biomechanics of the knee a few days ago and I cant quite picture the movement of the knee being different from a squat. Actually, the only difference I can think of is that the weight is placed on the top of the shins instead of directly above the knee. If this is a good start in understanding the difference in the extension/flexion of the knee, let me know. P? Cow? Did Cow get slaughtered? Where the fuck has he been? 6' 209lbs (8/16) Bench 365 (12/3) Weighted Pullups 80lbs 3x3 (3/19) Squat 370 Deadlift after herniation 385lbs 3x3 (3/17) NASM certified 2/06 Journal

03-27-2007, 06:30 PM	#4
Duncans Donuts Stay puffed, baby. Join Date: Jul 2004 Location: CA Posts: 2,776 Photos: 2	doing leg extensions, don't let the resistance go the entire 90 degrees from full extension (i do 4/5 of the total range of motion) - this keeps tension on the quad group as well as prevents higher shearing force on the knees. no leg extensions are not bad for you "in the howling bleeding nights, the dogs plunge into the Volga and swim desperately to gain the other bank. The nights of Stalingrad are a terror for them. Animals flee this hell; the hardest stones cannot bear it for long; only men endure."

03-27-2007, 06:38 PM	#7
Duncans Donuts Stay puffed, baby. Join Date: Jul 2004 Location: CA Posts: 2,776 Photos: 2	i mean away from leg extension, when the knees are flexed. don't allow the shins to go further than a 90 degree angle relative to thighs. if you let your knees continue to flex, you are removing tension from the thighs. that is why you do 4/5 of the way, to prevent shearing and maintain tension. "in the howling bleeding nights, the dogs plunge into the Volga and swim desperately to gain the other bank. The nights of Stalingrad are a terror for them. Animals flee this hell; the hardest stones cannot bear it for long; only men endure."

03-27-2007, 09:06 PM	#9
CowPimp Fueled by Testosterone Moderator Join Date: Jan 2004 Location: Silver Spring, MD Posts: 15,615	I've read far too many suggestions from fitness professionals suggesting you have to make various alterations (Though they don't always agree entirely) to the movement in order to prevent unwanted shearing forces on the knee. I just avoid it because there are plenty of other exercises out there that are less controversial. The only time it's bad to feel the burn is when you're peeing... Belligerent Bovine badass YouTube Videos

03-27-2007, 05:38 PM	#2
NeilPearson Registered User Join Date: Sep 2005 Location: Phoenix, AZ Posts: 2,518	I think that is how I herniated a disk in my back

03-27-2007, 07:14 PM	#8
Goodfella9783 Registered User Join Date: Dec 2004 Posts: 4,226	That may be hard to do considering some machines may start past that 90 degree angle. At least the ones on home gyms that aren't adjustable. I'm going to go check out the extension part of my bench real quick.

03-28-2007, 01:23 AM	#12
slip Registered User Join Date: Jan 2006 Posts: 346	Havent had any noticeable bad sensations in my knees from them, but definately see the potential for Bad Things. On a related note, started using more weight on the seated hamstring curl machine (up to 220lb) for 10 reps and have a strange sensation in my knees afterwards. Definately some uncool forces going through them at that weight.

03-28-2007, 01:46 AM	#13
blueboy75 Registered User Join Date: Nov 2004 Location: Melbourne Posts: 307	I do single leg extensions as a light warm-up before commencing my squats - feels pretty good for me.

03-28-2007, 10:11 AM	#15
AKIRA I am Rollo Tomassee.. Elite Member Join Date: Jul 2005 Location: Outside the box Posts: 8,787 Photos: 3	I suppose you can adjust the machine to make it start at or passed 9 0 degrees, but the ROM would be shortened. And if the ROM is shortened, then the workout isnt as effective. I personally havent ever had knee problems on the machine, but thats not why I dont do them. I dont do them cuz of the warnings and the boredom. I always felt my legs;s muscles near the knee being worked and sore. Never anywhere up my leg near my torso. 6' 209lbs (8/16) Bench 365 (12/3) Weighted Pullups 80lbs 3x3 (3/19) Squat 370 Deadlift after herniation 385lbs 3x3 (3/17) NASM certified 2/06 Journal

03-28-2007, 06:45 PM	#20
VILBAUGH Member Elite Member Join Date: Oct 2006 Location: Ontario Posts: 131	the answer is simple; the movement on the "leg extension" is not functional. Every time you get off a chair, you squat....very functional.

03-28-2007, 11:26 PM	#22
Nate K Registered User Join Date: Nov 2004 Posts: 1,739 Photos: 3	Why would you want to do seated presses?

03-29-2007, 07:15 PM	#25
VILBAUGH Member Elite Member Join Date: Oct 2006 Location: Ontario Posts: 131	Why would you want to do standing presses? Anytime I ever lift a load overhead while living life outside the gym is in the standing position, so why sit down? what if you had to do more than 4-20 reps? say lifting people or sand bags or boxes of bannanas or anything, Im pretty sure you'd want know how to lift it while standing and maybe have a little support from your hips while doing it.... Last edited by VILBAUGH : 03-29-2007 at 07:48 PM.

03-29-2007, 07:30 PM	#26
VILBAUGH Member Elite Member Join Date: Oct 2006 Location: Ontario Posts: 131	bench press is definitly functional, your pushing a load off and away from your body, if it were any other situation, like being pinned, I couldn't see myself bringing the load behind my head for a "tricep extension", that to me would be silly. however you are right about one thing, seated pesses are not functional. serious powerlifters will pin the bottom of the stack on a leg extension apparatus and achieve many reps having never used it. only squatting. Last edited by VILBAUGH : 03-29-2007 at 08:03 PM.

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