what is wrong with my knees, pls help!

I am 80kg, i can deep squat 130kg 5 reps, but when i use leg extension, even 20kg kills me,
my knees really really hurt when i do leg extension, but for squat, it is ok.

what is wrong with my knees? thanks

Where exactly does it hurt?

My understanding is that leg extensions put more of a direct sheering force on your patellar tendon.  May even have to do with the fact that there is no compressive loading un the joint itself throughout the ROM, other than that supplied by the quadriceps themselves.

My home away from DBB

Okay, injured knee guy here (actually just iced my left knee).  All you experts correct me if I'm wrong, but during a squat the greatest resistance (tension) felt by the knees is at the bottom of the move, when knee angle is the greatest.  On the leg extension resistance is constant throughout the range of motion.  It occurs to me that the squat is a natural "standing up from crouched down" move whereas there is no natural equivalent to a leg extension, right?  That means it's a foreign move to the body and prone to complications if not learned slowly.  I know what Veg is talking about regarding shear:  You've got that pad pressing down hard on your quads right near the patella, your hammies pressing hard into the edge of the seat, and a roller pressing hard into your shins.  There are more comforting sensations, imo.  I usually fold a towel over the edge of the seat.  Helps me.   But extensions are great for getting that squeeze in the quads.  Good luck!

Simple solution - stop doing leg extensions.

"True genius, in many fields of human endeavor, is often revealed in elegant simplicity."

- A smart man

Journal: http://www.wannabebigforums.com/showthread.php?t=117358

I've heard of a lot of people having problems with leg extensions; especially when they swing and use momentum to move the weight. In my opinion they are a useless isolation anyway; you don't really need them.

brihead301


Simple solution - stop doing leg extensions.

HA HAAAAA!!  "Doctor, it hurts when I press here."

"Then stop pressing there, genius."

Just kidding   That may ultimately be the solution, if we're talking about a condition that will improve with rest.  If it's an inflammation of some kind, that really is the only prescription.  But if it's soreness caused by some kind of imbalance, then it's not going to get better by avoiding it.  You have to correct the imbalance.

Does this pain occur at any weight?

My home away from DBB

no, that is not caused by leg extension, i seldom do it, before i begin  doing heavy squat, i have no problem if i occasionally try leg extension. And nealy everyone can do  it, even girls can do a least 50kg.  

but once i began regularly doing deep squat.  i noticed i have this problem

even with 10 or 20 kg on the machine, every time i try to extend my legs from right angel to straight. it hurts like hell.    it hurts most at the begining of each rep.  once the leg is 120 degree, it is fine.

but when i squat, i do not have problem. 
how to solve it? thx

your knee's were never meant to be isolated like that, we didnt evolve over millions of years doing knee extensions. Typically it wont hurt most people but its not beneficial either.

if your squating and your fine then thats all that matters. As brihead said, simple solution is to stop the knee extensions, which you should never do in the first place.

If your looking for other leg exercises there are much better ones out there.

6'3"  @213

Squat 1x20x275

press:200, Deadlift:475, Bench:300, P.clean:235, Squat:385

"The only failure that is final is to stop trying to improve"

Is there a setting to adjust the leg angle at the beginning of the contraction to 120 degrees so you're beyond the pain point?

Haha, agree with Bri here.

If you can continue to progress on the squats, I would say, avoid leg extensions.

5'8.1"
Age = 20 
started in February 16th 2007: 58kg (127.6lbs)
current : around 79-80kg (173.8lb-176lb)

thanks guys, i just want to know why it hurt so much, and how to avoid it.
i rest a few weeks, and try again, the problem is still there

comeonin


thanks guys, i just want to know why it hurt so much, and how to avoid it.
i rest a few weeks, and try again, the problem is still there

I'm thinking about making an appointment to see a sports specialist about my knees.  If your problem continues, maybe you should see a doc.

I used to do leg extensions and I would go max weight on the machine for a good 3 sets of 12 reps.  I could feel it a bit in my quads but my knee health didn't seam that great.  Soon as I stopped the feeling of possibly developing knee problems went away.  I don't think leg extensions are worth messing with.

http://www.discussbodybuilding.com/Seos-Log-2008-m442008.aspx

Leg extension machines should all have a weight limit on them....  They are a Physical Therapists "dream"...er at least for job security.  There is a place for those machines but it is not w/ heavy weights.  That's a lot of weight under tension your patellar tendon is supporting......  Stick w/ closed chain exercises and dont' do anything that causes pain.  "no pain, no gain".....is a bunch of crap when it comes to joint pain.  Be careful....and skip what hurts.  Not worth it.

I will never be done learning.... 
ACSM cert. Personal Trainer
Long term goal: Maintain 13%
Currently: 9.5%

if your squating and your fine then thats all that matters. As brihead said, simple solution is to stop the knee extensions, which you should never do in the first place

the quest for the true answers solved..

DONT BLAME THE PITBULL TRAIN THE PITBULL .BAN THE DEED NOT THE BREED.... OH YES MY GRAMR AND SPELNG SUCK AZZ...I KNOW.. THERE ARE NO BAD DOGS.JUST BAD OWNERS...

idk why they would hurt you , if anything they help secure your knee's they helped increase my squat after awhile , i never had problems with them before .... but who know , sure someone does


stop doing em is my answer