at 5'10" I'd be really surprised if you are "supposed to" have 160mm cranks. Unless you should have been 6'5" but broke the growth plates in your knees at age 8.

I would strongly suggest you stick with the normal 170mm cranks, unless you have REALLY proportionally-short legs and long torso. Even then, 165 is the lowest you should go, and that's a fairly common, easy-to-find size. 160 and below get into rare territory.
There's also some personal-preference variation that has some relation to pedaling style. If you like to spin a high cadence, shorter crankarms make that easier. Longer crankarms are better for stomping at lower rpms.