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Some say it's a knee wrecker.
Some say don't fully contract the knee because it will fuck your knees up.

i jumped onto my leg extension yesterday, to do my 12 rep's and noted that someone was using the whole stack.

(id done a set on the leg press
jumped on the hammer for twenty reps, then the leg extension) my quads were fried and I wanted to make sure they received enough work.)

My first thought was this person who used this machine prior to me was either huge, and I mean has thighs the size of a mature bull elephants leg which I doubt, or as I've stated before he is just stupid and tough....is on their way to a blown knee, not now, but at some point in the future
ive seen blokes load up the machine and swing away.

let me point out the mechanical inefficiency of the leg extension, I'll keep it brief and hope you understand.

if the quad is producing force of say 1200 pounds to lift the weigh, 1000 is exerted over the top of the kneecap and remainder is lost through friction.

the effective point of attachment is halfway down the shin in the wrong direction, 80% of the force is being wasted.

a man pulling lifting 300kg produces 4000kg of pulling force with the quad, exposing the knee to 7000kg of compression force.

salient points:

So, lessen the weight, move slow, move even slower on the negative phase and fully contract the quad and squeeze the shit out of it and hold for two seconds, at this point ther is zero force on the knee, and 100% on the quad, full resistance on a contracted muscle is where all the magic happens.

Make sure your hip is anchored in the seat and the backrest is angled back.
 
I was on the "leg extension wrecks your knees bandwagon", but the past couple of years have re-introduced them with no ill effects.
Silvergoose makes a good point about lessening the weight and concentrate on the negative.
I see no reason (if done correctly) not to do leg extensions.
 
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I would also suggest to get the seat adjusted right. If it's too close or far away, it can really hurt your knees. However when set up correctly, you won't feel it in the knees at all.
 
I would also suggest to get the seat adjusted right. If it's too close or far away, it can really hurt your knees. However when set up correctly, you won't feel it in the knees at all.

Good pick-up...The knee joint needs to be aligned with the axis of the moment arm(lever)
 
Some people like to load up the weight and then use their body weight to lever the weight up rather than their legs. Stuff like that is when problems happen.

People love a bag guy and it seems leg extensions are that scapegoat for some people.
 
Great tips, [MENTION=3627]Silverback[/MENTION];

Timely post for me. I avoided leg press for years. Only just got back to doing them while I was prehabbing for hip surgery.
Will be using them again during my rehab once I'm allowed to do them.
Keeping the weight light and using slow, controlled movements and focussing on the negative would be PERFECT.

big thumbs up, thank you.
 
Great tips, @Silverback ;

Timely post for me. I avoided leg press for years. Only just got back to doing them while I was prehabbing for hip surgery.
Will be using them again during my rehab once I'm allowed to do them.
Keeping the weight light and using slow, controlled movements and focussing on the negative would be PERFECT.

big thumbs up, thank you.

No worries!

Thanks.
 
it's complex stuff, [MENTION=3627]Silverback[/MENTION]; :eek:

I love chocolate too. Oh wait, that's a redundant statement

Leg extensions not so much LOL
 
I love penis extensions, but since we are on legs, here is my 2c worth.
The seat plank angle makes more difference to me than the back rest position, too much back angle and it loads my knees way too much.
Good call on the slow and hold movement, swinging is next to useless, squeeze the living kunce out of them at the top, also gives you some time to admire them at the same time, win win, kunce.
 
I've seen plenty of leg extension machines where the seat angle is pivoted way up with no adjustment options available. Full retard I reckon. Who sits like that?

3 sets of slow extensions after deadlifts at the 12 rep range usually has my thighs begging for mercy. Got to try the squeeze bit at the top though, it sure sounds like fun..
 
The seat plank angle makes more difference to me than the back rest position, too much back angle and it loads my knees way too much.



The angle of the seat plays no part on loading the knee, you might be confusing the fact that the length of the seat may be to long and restricts movement.

The angle of the back rest is important in that too much forward lean rotates the hip and the hammies then pulls on the knee joint, restricting movement.

Think before you type.
 
3 sets of slow extensions after deadlifts at the 12 rep range usually has my thighs begging for mercy.

Not sure I get that, dead lifts and extensions? One hits hamis the other quads.
Normally they follow squats and hack squats.
 
The angle of the seat plays no part on loading the knee, you might be confusing the fact that the length of the seat may be to long and restricts movement.

The angle of the back rest is important in that too much forward lean rotates the hip and the hammies then pulls on the knee joint, restricting movement.

Think before you type.

Only in your ignorant, ancient and theoretical world, simply typing what I experience, time after time, if you can read, than you will see the words "to me" sitting with hips low and knees high grinds them.
Do you really think you the only kunce on here with 20+ years doing this shit?
 
Not sure I get that, dead lifts and extensions? One hits hamis the other quads.
Normally they follow squats and hack squats.

True that, I just decided to go 'full leg' when I decided to pair the extensions after deads on the half dozen occasions I had the motivation to do so.

Goodness me, hack squats.. more like yack squats! lol
 
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