A pose that the modern woman assumes in photographs to diminish the abundance of flab on her inner arm.

To give the deceptively casual appearance of a well-toned extremity, a female will place her hand on one hip, bending the elbow at a near-90 degree angle to prohibit excess fat from collecting next to her torso.
I had to untag that picture because I looked like I was about to ship out to fat camp; I forgot to strike a skinny arm.

Even out of shape men can rock a nice skinny arm.
by The Original Chubster June 9, 2010
Get the Skinny Arm mug.
A trick girls do in photos to hide the fact that they have fat arms.

It is performed by placing a hand on your hip and angling that arm with your body, like a "teapot".
I wasn't sure if that girl on Facebook was fat or not until I noticed she was doing the skinny arm trick in every photo.
by FlabbyBingoWings April 24, 2012
Get the skinny arm trick mug.