Why internally rotate shoulders for dumbbell fly?

Discussion of peer refereed articles and clinical applications

Moderators: Ironman, Jungledoc, darshana, stuward

Post Reply
fluoresce
n00b
n00b
Posts: 13
Joined: Tue Aug 23, 2016 12:10 pm

Why internally rotate shoulders for dumbbell fly?

Post by fluoresce » Sat Dec 03, 2016 4:40 pm

For the dumbbell fly and lever seated fly, ExRx says that you should internally rotate your shoulders.

Why?

I thought it was to better isolate the pectoralis major; however, according to Wikipedia's Chest Fly page, if you internally rotate your shoulders, your anterior deltoids get more involved:

"The chest fly ... primarily works the pectoralis major muscles to move the arms horizontally forward. If internally rotated, it is assisted in this by the anterior head of the deltoideus in transverse flexion. If externally rotated, the contribution of the deltoid is lessened and the pec major is strongly emphasized as the transverse adductor."

Why, then, does ExRx recommend internal rotation? Have I misunderstood or something?

Here are the ExRx exercise pages:

exrxDOTnet/WeightExercises/PectoralSternal/DBFly.html
exrxDOTnet/WeightExercises/PectoralSternal/LVSeatedFly.html

User avatar
stuward
moderator
moderator
Posts: 6612
Joined: Sat Mar 10, 2007 5:44 pm
Location: Halifax, NS

Re: Why internally rotate shoulders for dumbbell fly?

Post by stuward » Sat Dec 03, 2016 10:07 pm

I don't know enough about this exercise to voice an opionion, however, Wikipedia uses this page for their source: http://www.fitday.com/fitness-articles/ ... t-fly.html" onclick="window.open(this.href);return false; However, that article doesn't even mention internal or external rotation. I wouldn't place any faith in it.
Stu Ward
_________________
Let thy food be thy medicine, and thy medicine be thy food.~Hippocrates
Strength is the adaptation that leads to all other adaptations that you really care about - Charles Staley
_________________
Thanks TimD

fluoresce
n00b
n00b
Posts: 13
Joined: Tue Aug 23, 2016 12:10 pm

Re: Why internally rotate shoulders for dumbbell fly?

Post by fluoresce » Wed Dec 07, 2016 11:22 am

Thanks, Stuward. :-)

Post Reply