Could Carol Anne Gotbaum—the daughter-in-law of New York City Public Advocate Betsy Gotbaum who died in police custody at the Phoenix airport—really have strangled herself to death while trying to lift her handcuffs over her head? Can anyone actually perform that maneuver? Slate investigates and says yes. Sorta!
First, push the left arm as far to the right as possible, or dislocate the shoulder altogether. Rotate the right wrist clockwise within the handcuff until the inside of the wrist faces outward, then bring up the right wrist as if in a bicep curl; the left arm will be tugged upward at the same time. Next, the right arm moves up, scraping up the shoulder blade, until both hands are basically behind the neck and the right elbow points up above your head. Then, tucking your chin into the chest, bring the crook of your right arm over your head. To finish the maneuver, pop the handcuffs around the left forearm, dislocate the left shoulder (if you haven't already), and bring the left arm down in front. (Here's a slow-motion video of the whole thing.)
Of course whether an obviously agitated woman in the throes of what sounds like some kind of breakdown brought about by substance withdrawal would have the foresight to carry such a complicated operation about is an open question, but, hey, maybe she was a professional contortionist.