The fellas over at /fit/ and /pol/ are having a problem and we need your help /sci/
>>>/fit/36069624
The manlets when doing bench press only have to go to a 90 to 100 degree angle bend with their arms. Compare that to a person that is 6'2" and they are having to go to a 45 degree bend.
We need to develop a standardized chart of strength relative to range of motion and height. Was hoping you guys could help us out with calculating the mechanics for this
>>7871765
The farther a given weight is from your body the higher the torque will be
>>7871765
Energy spent on doing a bench press only depends on the distance the barbell is travelling. So a guy with longer hand is spending more energy because he is pushing the barbell further up.
But you are probably more interested in the power output (strength), since longer arm guy probably takes longer to do a bench press, I would say both of them are are using same power.
You divide the distance the barbell travelled with the time it took to do a single bench press and you will get something that is proportional to the power used.
>>7871765
I don't understand, how is hight related to the angle you have to move through? I just don't see how the two are related, surely everyone has to move through the same angle. Particularly with squats.
>>7871784
When the bar touches your chest. A manlet's arms are only bent at a 90 degree angle when the bar is as far down as it will go. A lanklet's arms are bent at a 45 degree angle when the bar is as far down as it will go.
>>7871802
Okay well in that case instead of focusing on the angle your arms move through look at the work done.
>>7871808
The two are not equal. The taller person is clearly exerting way more energy and the body mechanics for the tall person are way more demanding than that of a manlet.
why do you /fit/ faggots keep coming here and asking retarded questions
>>7871817
If you don't know the answer don't comment. I'm trying to have an intelligent discussion here.
>>7871824
It is an interesting question, I have studied physiology and mechanics and cant figure out where to start...
>>7871812
I'm not convinced by that (unless you can demonstrate otherwise). Take a manlet doing squats, they might move through (pulling a random number out the air) 0.3m while a lanklet might move though 0.6m. If they both squat the same weight then the lanklet would have done more work than the manlet. which means that the manlet would have lift more in order to the same work. Also I quite like this answer >>7871782, which is essentially the same as what I've said.
>>7871765
Wingspan is supposed to be pretty close to a person's height. Even if there was a discrepancy of a foot between two people, the difference in arm length would be about six inches which isn't really enough to cause that drastic of a change in form.
Sorry dude, you'll just have to find another lie to tell yourself about why you can't get laid at the club
>>7871858
I just explained the angular difference 45 degree bend compared to a 90 degree bend. That is pretty significant.
>>7871802
no. that's not physically possible
Equalize the angle. Either lanklet only goes to 90* or you both use hand weights and take it to 45*.
Now you need to decide about what proper technique is and who is disadvantaged more.
>>7871812
>energy
that means fuck all. you are interested in power, which depends entirely on the time spent doing each rep, and is certainly not standard amongst people
>>7871940
and when you say energy, you're also assuming that each person only lifts with enough force to raise the weight with constant speed, which is not the case.
>>7871930
I spotted the buttsour manlet.
Please try and keep your inferiority complex separate from these scientific matters at hand.
>>7871948
read: you can lift 135 lbs of weight with 135 lb upward force or 160 lb upward force, or 500 lb upward force
>>7871949
show me a person whose forearm has no length to it, because thats what you're implying you closeted faggot
>>7871956
he is not capable of understanding your point
>>7871956
This is really fuckin dumb. Why can't we just use bodyweight to lift ratio like we have for a billion years? Manlets have less distance to cover, but also smaller muscles.
>>7871961
>he's a midget
>his arms are at a ~40-60 degree angle
>its not a fucking arm exercise
you're dumb as shit
>>7871961
brainlet
>>7871970
That's a squat not a bench press. I was making a joke.
Look at this guy https://youtu.be/XZfsqdCOiTg?t=1m3s
This is how manlets do bench press
>>7871765
This is simply a ratio problem.
Work done = Force * distance moved
In your case, it simplifies to:
W1 * ATF1 = W2 * ATF2
>>7871802
I don't understand, why wouldn't the larger guy change his grip position so he does relatively the same motion?
>Height equals wingspan
Lmao
I know a 5'9 dude with longer arms than a 6'0 dude
Keep making excuses for your shit genetics
>>7871983
Even if he did his muscles are more spread out than the manlet therefore its more difficult.
>>7871765
This is broscience at its best. Enjoy doing a meme exercise that will likely lead to shoulder injury :^)
>>7871975
Notice him taking videos from an upward facing angle to instill a sense of false sense of height and power. Typical manlet inferiority complex.
>>7871981
full table since print preview cut off the bottom of the lbs.
>>7871994
I'm not understanding what point you're trying to make with this graph. That 394 pounds for someone with 33" feels like 619 pounds?
>>7871989
I just calculated the difference solely based on arm length, holding all other things constant, such as explosion out of the hole (acceleration against gravity).
Without sensors on each individual doing the movement I'm afraid these tables are all you're going to get for comparison between arm length and weight moved.
>>7872004
Someone with 23" arms has to lift 254lbs to lift the equivalent of someone with 26" lifting 225lbs. While a person with 31" arms only has to lift 189lbs to do the same amount of work.
It's not that complicated, look up your arm length, look down to your bench numbers, read that row left to right to know what someone shorter or taller than you should be benching to bench the same as you.
>>7872015
Show me the mathematical proof
>>7872015
Gonna ignore triceps muscle size?
>>7872044
Work done = Force * distance
Force = m*a
Work done = m * a * d
m* a * d = m * a * d
m * d = m * d
mass proportional to distance moved.
distance moved proportional to arm length.
m1 * d1 = m2 * d2
for equal work done between two different distances:
If d1 = d2, m1 = m2
If d1 > d2, m1 < m2
If d1 < d2, m1 > m2
Shorter arm length must move more mass to account for shorter distance moved, to equal same work done.
It's a simple concept. If I push a box for double the distance, I do double the work. If someone has half the arm length as you and is doing a bench press, they are pushing the weight through half the distance and doing half the work, they would need to do 2 reps for your 1.
>>7872099
It has nothing to do with muscle size, just work done, which is Joules...
You're only taking into account a straight push as if the arms are straight the whole time. I'm talking the mechanics of an arm bending at the elbow at different angles for people of different heights.
I kind of feel like you're half assing this answer.
>>7872180
Gravity is path independent, so you'll do the same work regardless of the path you take.
>>7872182
Same overall work maybe, but I'm interested in the mechanics
>>7871828
tells alot about your specialization
>>7872191
This is mechanics. And if you're OP all I can say is anyone mentioning work or power has answered your question.
>>7872202
What did you get your degree in?
>>7872160
It's a bad way to measure strength from person to person. Heavier people will be able to lift more than lighter people because they have more muscular tissue. Heavier people (not saying fat btw, heavier weightlifters), tend to be larger in general, including height and arm length. They will do more "work." But the little guy lifting just as much as the big guy is more impressive.
It's really just a way for /fit/ to continue to propagate the lel manlet meme. 5'11" here btw.
>>7872219
Physics
>>7872180
I don't have to take anything into account.
I'm comparing the ratio between two fixed lengths- the range of motion of two different people pushing a bar up.
Is the bar touching your chest? Yes? Ok it travelled some distance to get there. Is your chest puffed up and bigger, are your arms longer or shorter? these are the contributing factors.
Assuming a flat back and similar chest sizes, all you really measure when two different people bench the same weight, is the extra distance the guy with the longer arms moves the weight. He will have to physically hold the weight up for a longer time, assuming they both bench at the same speed, and have to push it up higher to achieve lockout. This extra height he has to get is the extra work he does.
>> the mechanics of an arm bending at the elbow at different angles for people of different heights
maybe you should learn how to bench, elbows flared 45 degrees, scapula retracted, hands wider than shoulder width apart, bring bar down to below nipples, push bar up to mid chest.
If you have shitty bench form that's not long or short arms, that's you being a fucking retard and not understanding how do to the exercise.
>>7872221
nobody is measuring strength, simply work done. No shit bigger people are stronger and better at lifting weights. You want to measure strength then simply use something like
http://www.strgraphs.com
Fuck I swear, some people are just born with a noodle brain. This idiot wanted a "mathematical proof" for a fucking linear proportionality. Help guys I don't understand how to multiply two numbers :(
>>7872274
>They don't have Bachelor's in Physics.
I'm out.
>>7872275
You must have gone to school in Europe. They don't have that here in America.
>>7872286
You get a B.Sc or a B.S. in a subject. So you get a B.Sc in biology or a B.Sc in physics. So you're degree is in what ever it says on your diploma.
>>7871988
so instead of lifting more and trying harder you're gonna ask for charts?
make the fucking chart yourself, do your own research. the math behind it is basic and you can find help on khanacademy
>>7872274
5'10 220x5
>>7871765
In order to go from 45 to 90 degree difference in bending when lowering to the same point then the 6'2" person would require insanely long arms. In particular if the 6'2" person's arms would have to be approximately 185% ( [math]\sqrt(2 + sqrt(2))[/math] ) as long as the manlet's.
I could quickly make you an interactive online model but since you brought /pol/ here then the largest amount of effort I can justify is to show you that you are retarded (or else you're likely to stick around). Fuck off back to your board and take /pol/ with you.
It's also worth pointing out that the smaller person requires less muscle to output the same amount of force thanks to babby mechanics.
>>7873503
Whoops.
[math]\sqrt{2 + \sqrt{2}}[/math]
>>7871782
The 'power' answer sounds about right.
>>7873503
You can browse more than one board...
Besides, I haven't redirected any /pol/ traffic here either.
>>7873600
Sure, except that only retards browse /pol/. So given that we don't like retards in /sci/ you can GTFO.
