Thread: Dumbbell fly form?

Is it bad for your arms to go behind the plane of your body when doing flat dumbbell flies with light weights? If I'm doing a lot of reps I like to use a small amount of weight, do a high amount of reps, and then hold my arms on make shift surfaces that are kinda lower than my bench and body's plane, while taking deep breaths because I feel it gives my chest a great stretch. I just don't want to put my shoulders in a vulnerable position, but it really doesn't feel bad. However, I've read/heard not to let my arms or shoulders dip below the body.

You can hyper extend your shoulders no matter how light the weight is.