There are two main hypotheses examined in the dissertation. The first is that the physiology of the hand provides motivation for the claim that sign language handshapes can be considered easy, hard or even impossible to articulate. The second hypothesis is that easy handshapes occur more often than expected, hard handshapes occur less often than expected and impossible handshapes don't occur at all within a single sign language. These hypotheses are examined in the following ways: first, I provide a detailed explanation of the physiology of the hand from which I conclude that not all fingers are equal in skill and not all configurations a hand may assume are equally easy. Second, based on the physiology, I propose a metric for determining which handshapes are "easy" and which are "difficult". Third, I examine whether the "easy" handshapes occur more often than expected, while the "hard" handshapes occur less often than expected in the signs of two languages, American Sign Language (ASL) and Taiwan Sign Language (TSL). I conclude that the hypothesis that the "easy" handshapes occur more often than expected and the "hard" handshapes occur less often than expected is supported in approximately half of the cases.