Plate Setup Cross Comparison For Plate Curls

[acorn]

So I've been thinking about this a bit for the last couple days. Forewarning I may ramble a bit as I'm still getting my brain around this. How can I get a better estimate of load in plate curls so that I can progressively increase easier. The jumps from 25 to 35# are pretty big for most people and plate curling a 45# plate seems nearly insurmountable. I think some of this challenge is due to how big the torque jumps are between them. Anyway in thinking about this a couple nights ago I mocked up a quick way to test relative torque load with different plate and plate stack combo's in order to test theory. I ended up using a large wood clamp to hold the plate similar to hand and set a pivot point at the bottom of the clamp just off the ground. With the clamp arm vertical I attached the digital hanging scale I use for gripper cals to the bar at 14" from the pivot point. Distance from center of 10Kg plate to that vertical bar was 7". Upon checking with the load scale I was getting 11lbs or 5Kg at the 14" point. By adding a 2nd 10Kg plate the value at the scale doubled just as expected.

Today as I'm working from home watching a sick kiddo I was thinking about it again and the calculation aspect of it to determine something really comparable. I took a measurement of distance from center of hole in 10Kg plate to my wrist when in my hand. Plate radius on that on is 7" and I got 9.75" to the wrist. Torque at wrist for me would be 9.75" x 22lbs or roughly 215 in/lbs of torque. Measured some of my other plates as well. 25# plate was 5.5" radius or 8.25" to wrist. That one calculated out to be 8.25" x 25lbs or roughly 206 in/lbs of torque. No wonder it always felt a little easier despite being heavier. A 35# plate I have measured in at 7 1/8" radius which would work out to ~345 in/lbs of torque. One of the 15Kg Eleikos was 8" radius so it would work out to ~355 in/lbs of torque, no wonder it feels a little tougher. Did a quick test as well with stacking. bolted additional plate through the middle hole to main plate so they would have the same centerline and same moment. Found I could not quite do the 10Kg plus 5Kg plate plus 1Kg bolt setup right now on the 10Kg plate. that worked out to 16Kg x 9.75" or about 344 in/lbs. Just tried the 15Kg Eleiko and the 35# plate and nope can't do it either right now though I normally can get a few reps with them. They feel about the same to me.

Next I dropped the setup down to 10Kg + 2.5Kg + 1Kg bolt through ~ 13.5Kg. Could not do it easily and got it maybe half way up without pushing. Dropped to 10Kg + 1.25Kg + 1Kg bolt through setup or 12.25Kg or ~ 263 in/lbs of torque and got 3 reps without pushing too hard. I still need to go back an measure with clamp lever but I'm hoping a similar ratio emerges.

I may figure out more as I test but wanted to get this written out while I'm thinking about it. Would be nice to be able to progressively microload your way up to a 45# plate curl.

- Aaron

[JaredWith1R]

Yes! So much Physics, I love it.

Why are you measuring to your wrist? I haven't done plate curls, is the wrist strength the major limiting factor? Biomechanically speaking, you could measure the distance from the center of the plate load to the elbow, which would give you the force required by your bicep to execute the curling motion, but that would simplify the scenario and take grip strength out completely.

When you stack plates, it would be best to stack them evenly on either side of the gripping plate, to keep the center of mass inline with your forearm, but that change would really only be a fraction of the weight, anyway. For example, shifting the center of the stack height up 3 inches would change your lever arm distance from 9.75" to 10.2", a 4.7% increase. Pretty minimal, but that takes your 215 in-lb curl to almost 225 in-lb at the wrist.

Man, I miss engineering....

[acorn]

Yes! So much Physics, I love it.

Why are you measuring to your wrist? I haven't done plate curls, is the wrist strength the major limiting factor? Biomechanically speaking, you could measure the distance from the center of the plate load to the elbow, which would give you the force required by your bicep to execute the curling motion, but that would simplify the scenario and take grip strength out completely.

When you stack plates, it would be best to stack them evenly on either side of the gripping plate, to keep the center of mass inline with your forearm, but that change would really only be a fraction of the weight, anyway. For example, shifting the center of the stack height up 3 inches would change your lever arm distance from 9.75" to 10.2", a 4.7% increase. Pretty minimal, but that takes your 215 in-lb curl to almost 225 in-lb at the wrist.

Man, I miss engineering....

Yes! my physics is a bit rusty since I have been working in IT for many years. I did study Mechanical Engineering in College though. Yes for most people the wrist strength is the limiting factor that is why I measured to there as the lever fulcrum. Another interesting aspect is adding weight in the middle vs outside edge. If you calculate the moments separately you can see how much more tension in the form of torque is added by moving the load to the outside edge of the plate. Yay science!

- Aaron

[Jones1874]

i would go mad if i thought about plate curls in that much depth..

why not just build a homemade ironmind stacker and add small increments gradually? my most recent PB is 7kgs for 16 reps, and i can rep a 10kg plate cold quite comfortably. Like Dax said in another thread, just use a strong pony clamp to microload the end of the 10kg plate until you can manage a 15kg plate, and so on..

no offence meant what so ever, just seems like your looking into it a bit too much. something i often do myself.

Edited February 4, 2015 by Jones1874

[Anthony C.]

This is just incredible. I can picture it now....some sort of an Arizona grip page with a list of all the plates in increments up to 45 lb plates. Thank you for all this, Aaron

[JaredWith1R]

i would go mad if i thought about plate curls in that much depth..

why not just build a homemade ironmind stacker and add small increments gradually? my most recent PB is 7kgs for 16 reps, and i can rep a 10kg plate cold quite comfortably. Like Dax said in another thread, just use a strong pony clamp to microload the end of the 10kg plate until you can manage a 15kg plate, and so on..

no offence meant what so ever, just seems like your looking into it a bit too much. something i often do myself.

For me, half the fun is the science. The body isn't a perfect scientific instrument, so a 15kg curl one day might be nothing compared to the day before, but for me it feels easier to do things when I understand the science. It might even be a little boost to realize that you're only increasing by 10% instead of thinking of it in pounds. That might just be us engineering types, though.

To each their own, as they say.

Yes! my physics is a bit rusty since I have been working in IT for many years. I did study Mechanical Engineering in College though.

Me too, but I'm now in test equipment sales. I get to use words like Amps, Phase Shift, Frequency Source, blah blah blah, but no more engineering units. It's mostly just dollars, now.

It will be great to see the data some day.

[Jones1874]

i would go mad if i thought about plate curls in that much depth..

why not just build a homemade ironmind stacker and add small increments gradually? my most recent PB is 7kgs for 16 reps, and i can rep a 10kg plate cold quite comfortably. Like Dax said in another thread, just use a strong pony clamp to microload the end of the 10kg plate until you can manage a 15kg plate, and so on..

no offence meant what so ever, just seems like your looking into it a bit too much. something i often do myself.

For me, half the fun is the science. The body isn't a perfect scientific instrument, so a 15kg curl one day might be nothing compared to the day before, but for me it feels easier to do things when I understand the science. It might even be a little boost to realize that you're only increasing by 10% instead of thinking of it in pounds. That might just be us engineering types, though.

To each their own, as they say.

Fair point. just want to say that i didnt mean to criticise if it maybe came across that way..

[acorn]

i would go mad if i thought about plate curls in that much depth..

why not just build a homemade ironmind stacker and add small increments gradually? my most recent PB is 7kgs for 16 reps, and i can rep a 10kg plate cold quite comfortably. Like Dax said in another thread, just use a strong pony clamp to microload the end of the 10kg plate until you can manage a 15kg plate, and so on..

no offence meant what so ever, just seems like your looking into it a bit too much. something i often do myself.

I rarely leave training stones un-turned.

I considered that although yes it would be homemade and not anything like the Ironmind tool. Thing is I really want to be able to have comparable values of real plate torque vs device with plates in particular positions and I want to know loading so I can do things progressively within my required percentage jumps I program.

Sure microloading with ponyclamp works great but wouldn't you like to know how close you are to the next plate? Torque values could tell you that. My bests on plate curls although I am not near them at the moment are fair. I've done plate curls with 35# bumpers, 45's that are smaller diameter like a 35# plate and 2H plate curled for reps an old York 75# plate among other things. still a 45# plate curl on a full size plate felt very far away on full sized plate. When looking at torque values I can see why.

No offense taken. I focus on the things that are important to me and do not usually worry about what others think.

[odin]

Great work Aaron! Jedd sells a plate curl device that I tried at Nationals and it seems like it would be a good way to train with microloading.

I need to find a different way to train plate curls as they always flare up tendonitis in my wrist/elbow/bicep area at some point, even with careful warmup and progression. Anyone else love the exercise but get 'bitten' by it?

Maybe I need to just hold the plate for time at the most difficult position and slowly add time/weight?

[acorn]

Great work Aaron! Jedd sells a plate curl device that I tried at Nationals and it seems like it would be a good way to train with microloading.

I need to find a different way to train plate curls as they always flare up tendonitis in my wrist/elbow/bicep area at some point, even with careful warmup and progression. Anyone else love the exercise but get 'bitten' by it?

Maybe I need to just hold the plate for time at the most difficult position and slowly add time/weight?

Awesome. Yeah Tendonitis could be a problem. I haven't had that but I rarely train the exercise. Plate hold for time may be just the ticket. You could adjust the intensity down a little bit and that might help. Higher reps vs the max effort work may work better too. I find sets of 20 or more seem to work better for me on most of the wrist stuff I have worked. Less likely to irritate my own past issues anyway while still allowing for steady progressions.

- Aaron

[acorn]

Good example, adding a 1lb pony clamp at the end of the 10kg plate for me would add almost 17 in/lbs to the 215 in/lbs of just the plate or about 7.5% increase. Adding 1lb to the middle would add 9.75 in/lbs or about a 4.5% increase. I usually shoot for 2 - 2.5% increases per week in most things when strength training.

- Aaron

[odin]

Great work Aaron! Jedd sells a plate curl device that I tried at Nationals and it seems like it would be a good way to train with microloading.

I need to find a different way to train plate curls as they always flare up tendonitis in my wrist/elbow/bicep area at some point, even with careful warmup and progression. Anyone else love the exercise but get 'bitten' by it?

Maybe I need to just hold the plate for time at the most difficult position and slowly add time/weight?

Awesome. Yeah Tendonitis could be a problem. I haven't had that but I rarely train the exercise. Plate hold for time may be just the ticket. You could adjust the intensity down a little bit and that might help. Higher reps vs the max effort work may work better too. I find sets of 20 or more seem to work better for me on most of the wrist stuff I have worked. Less likely to irritate my own past issues anyway while still allowing for steady progressions.

- Aaron

Thanks Aaron! It seems like the wrist strength gained from plate curls would help a lot of other exercises; a lot of the strongest guys on thickbar/Inch are great at the plate curl (Glass, Horne, Eaton and too many others to list).

[Jones1874]

Great work Aaron! Jedd sells a plate curl device that I tried at Nationals and it seems like it would be a good way to train with microloading.

I need to find a different way to train plate curls as they always flare up tendonitis in my wrist/elbow/bicep area at some point, even with careful warmup and progression. Anyone else love the exercise but get 'bitten' by it?

Maybe I need to just hold the plate for time at the most difficult position and slowly add time/weight?

Awesome. Yeah Tendonitis could be a problem. I haven't had that but I rarely train the exercise. Plate hold for time may be just the ticket. You could adjust the intensity down a little bit and that might help. Higher reps vs the max effort work may work better too. I find sets of 20 or more seem to work better for me on most of the wrist stuff I have worked. Less likely to irritate my own past issues anyway while still allowing for steady progressions.

- Aaron

i also aim for 20 reps. its always worked for me up until now. as i was trying to advance to that next plate, i think ive either put my training days too close together, or its the higher weight / low reps is what has strained my wrists.

[acorn]

Good example, adding a 1lb pony clamp at the end of the 10kg plate for me would add almost 17 in/lbs to the 215 in/lbs of just the plate or about 7.5% increase. Adding 1lb to the middle would add 9.75 in/lbs or about a 4.5% increase. I usually shoot for 2 - 2.5% increases per week in most things when strength training.

- Aaron

To expand upon this a 2.5# plate added to the outside edge of my 10Kg plate in this case would be a 20% increase in tension via torque. added to the center it would add 10% increase in torque.

- Aaron

[Jones1874]

Great work Aaron! Jedd sells a plate curl device that I tried at Nationals and it seems like it would be a good way to train with microloading.

I need to find a different way to train plate curls as they always flare up tendonitis in my wrist/elbow/bicep area at some point, even with careful warmup and progression. Anyone else love the exercise but get 'bitten' by it?

Maybe I need to just hold the plate for time at the most difficult position and slowly add time/weight?

i get 'bitten' by it aswell at times. i normally do about three or four stretches with my hands to relieve the stress on my elbow, as well as use my opposite hand to get the 'knots' out of my forearm. they both help alot, but self myofacial probably helps the most.

for what its worth, i get niggles around the bottom inner part of my forearm. thought id mention it to see if your getting it in the same area.

[Jones1874]

Thanks Aaron! It seems like the wrist strength gained from plate curls would help a lot of other exercises; a lot of the strongest guys on thickbar/Inch are great at the plate curl (Glass, Horne, Eaton and too many others to list).

Yori, mentioned this not too long ago in a PM. not sure if he mentioned it in a thread aswell.

and what you said about working the hardest part of the plate curl (plate parrallel to the floor) that works great aswell. i use to do this before plate curls. do both if you can, and maybe some 'plate wrist curls'. David Wigren recommends those.

[EJ Livesey]

This whole thread makes me think "dafuq??" This is way above my pay grade lol.

[jvance]

Hand length and total surface contact area would determine the final amount of tension. Inch pounds/length inches that contacts the bottom of the plate. I'm not a math guy so chime in if this is incorrect, makes sense to me though. Thumb length, rim width and rim shape all factor in too... Not sure exactly how it factors mathematically.

Edited February 5, 2015 by jvance

[JaredWith1R]

i would go mad if i thought about plate curls in that much depth..

why not just build a homemade ironmind stacker and add small increments gradually? my most recent PB is 7kgs for 16 reps, and i can rep a 10kg plate cold quite comfortably. Like Dax said in another thread, just use a strong pony clamp to microload the end of the 10kg plate until you can manage a 15kg plate, and so on..

no offence meant what so ever, just seems like your looking into it a bit too much. something i often do myself.

For me, half the fun is the science. The body isn't a perfect scientific instrument, so a 15kg curl one day might be nothing compared to the day before, but for me it feels easier to do things when I understand the science. It might even be a little boost to realize that you're only increasing by 10% instead of thinking of it in pounds. That might just be us engineering types, though.

To each their own, as they say.

Fair point. just want to say that i didnt mean to criticise if it maybe came across that way..

Hey man, no offence taken. No worries.

[JaredWith1R]

Hand length and total surface contact area would determine the final amount of tension. Inch pounds/length inches that contacts the bottom of the plate. I'm not a math guy so chime in if this is incorrect, makes sense to me though. Thumb length, rim width and rim shape all factor in too... Not sure exactly how it factors mathematically.

You would have to do In-lb / in^2 for total surface area of the hand, leaving lb/in. Really, all he is doing is providing a way to calculate the amount of torque, instead of just increasing in weight. The physical plate size is as much a factor in difficulty as weight change.

Basically, it is assuming that the hand grip is not of concern, and the difficulty occurs at the wrist. I believe.

[Lucasraymond]

I am the exception as I am average at axle but can plate/blob curl more than 99% of ppl! Jon V has a great point as hand placement, finger length, plate width, etc will change the external moment arm which would change perceived difficulty. i feel it more comfortable to curl something a little wider (blob) versus a thin plate. Definitely more strain on the wrist versus biceps by a lot!

[JaredWith1R]

I guess a blob curl would bring a lot more of your actual pinch grip into play, since it is so much wider. It puts the center of mass a lot closer to the center of your palm, so it should be less strain for your fingers as well as your wrist.

[David_wigren]

Handsize determine how hard it'll be on your thumb and fingertips. Length from center of plate to the wrist joint multiplied by the weight determine the wrist torque. Length from center of plate to elbow joint multiplied by the weight determine how hard it is for the biceps to curl it.

I can curl a blob if I scoop it. But I'm not strong enough to pinch lift it lol.

[James Fuller]

An Arm Wrestler who commented on one of my Plate Curling videos said." A Deep Dish/Large Rim 45lb plate is MUCH easier to Plate Curl since it will sit down into the palm of your hand like a blob." Never thought of it quite like that before!!

I 'microload' by using different sized plates as pictured here:

The large and more importantly THINNER Dan Lurie plate is a bear to Plate Curl!! The unbranded Ivanko is the easiest due to the Deep Dish design.

Edited February 5, 2015 by James Fuller

[Lucasraymond]

I guess a blob curl would bring a lot more of your actual pinch grip into play, since it is so much wider. It puts the center of mass a lot closer to the center of your palm, so it should be less strain for your fingers as well as your wrist.

Significantly less strain on the fingers with the blob compared to a plate which I feel like my fingers are the limiting factor with the 45 plate curl not necessarily wrist strength.