Pull up?

[Sonja]

Hi Cathe! I am trying to work on my posterior delt development and have just started doing pull ups. I can do 5 or 6 with an under-hand grip, and 3 or 4 with an over-hand grip. Can you tell me which grip incorporates more of the posterior delt? Thanks!

 

[Cathe Friedrich]

Hi Sonja! While pull ups may work the posterior delt to some degree, I would use pull ups more for training the back muscles, most specifically the upper outer back.

The muscle fibers of the posterior deltoids are best activated when the arm is in a slightly horizontally abducted (30 degree) position.

As for the actual grips that you mention, the underhand grip is more "user friendly", but if doing both grips do not aggrivate or strain your shoulders in any way, then do a few of each grip to work your muscle fibers slightly differently. Take Care!