A year old article, but timelessly relevant.
In the past year or so, there have been many discussions about how users hold their mobile devices—most notably Josh Clark’s. [2] But I suspect that some of what we’ve been reading may not be on track. First, we see a lot of assumptions—for example, that all people hold mobile devices with one hand because they’re the right size for that—well, at least the iPhone is. [3] Many of these discussions have assumed that people are all the same and do not adapt to different situations, which is not my experience in any area involving real people—much less with the unexpected ways in which people use mobile devices. - See more at: http://www.uxmatters.com/mt/archives/2013/02/how-do-users-really-hold-mobile-devices.php?#sthash.reeG2OpD.dpuf