Could someone explain to me what a narrow supinated grip chin-up is? ?

Question

also could someone tell me what this means "this will increase the overload for the elbow flexors." i got it from this site http://www.bodybuilding.com/fun/charles4.htm

Answer 1

Narrow grip means hands close together on the bar. Supinated means palms facing you. That position causes your elbow flexors (biceps, other smaller muscles) to work much harder and take more of the weight.

With a wide grip and palms away your back does more of the work.