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PostPosted: Fri Aug 11, 2006 6:03 pm 
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Howdy,

I'm Dave from Montana....a new member, but a long time visitor. You have a great site!

I'm trying to understand the information on muscle use in the various exercises. The weighted underhand chip-up involves two more synergists muscles, deltoid posterior and trapezius middle, beyond those listed in the weighted overhand pull-up.

No questions there....but, the biceps brachii is a dynamic stabilizer in the chip-up, and a synergist in the pull-up. It seems to me, with my very limited knowledge, that it would be just the opposite. Given this example, could you please explain how this works?

Thanks for whatever you can provide, and keep up the great work!

Old Rusty Iron Dave from Montana


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PostPosted: Fri Aug 11, 2006 8:51 pm 
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Old Rusty (daschneider?)

I would be interested in the explanation as well. Pull-ups with an underhand (supinated) grip has always given me a pump in my biceps, whereas this is not the case with an overhand (pronated) grip.

BTW, a pronated wide grip in pull-ups involves shoulder adduction, while a close grip - whether pronated or supinated - involves shoulder extension.


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PostPosted: Sat Aug 12, 2006 10:34 am 
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I believe the implication is that the pronated grip will invariably widen your grip and involve more shoulder adduction. An underhand grip is naturally closer.


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PostPosted: Sat Aug 12, 2006 7:57 pm 
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DeadFrog wrote:
I believe the implication is that the pronated grip will invariably widen your grip and involve more shoulder adduction. An underhand grip is naturally closer.


Not necessarily

http://youtube.com/watch?v=h84m5BXCxKs

About 2:20 in the video, Big Dice does a set of close-grip pronated pull-ups.

Warning! Profanity in the link


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PostPosted: Mon Aug 14, 2006 5:03 pm 
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Perhaps the biceps isn't as insufficient during pronated grip, seeing that supinated grip really puts the biceps into severe mechanical disadvantage by having the arms too elevated at the beginningof the motion and having the elbow already flexed just when the arm is coming down and the biceps would normally be ready to kick in. Seems like the biceps are abit more stretched and able to work when grip is pronated.


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PostPosted: Mon Aug 14, 2006 8:14 pm 
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DeadFrog wrote:
Perhaps the biceps isn't as insufficient during pronated grip, seeing that supinated grip really puts the biceps into severe mechanical disadvantage by having the arms too elevated at the beginningof the motion and having the elbow already flexed just when the arm is coming down and the biceps would normally be ready to kick in. Seems like the biceps are abit more stretched and able to work when grip is pronated.


One of the functions of the biceps is the supination of the forearm, and flexing the elbow with a supinated grip improves the biceps mechanical advantage. The standard biceps curl can be done with more weight than a reverse curl.


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PostPosted: Thu Aug 17, 2006 10:14 am 
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interesting, now I'm thoroughly confused, lol


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