An approach to path movement in the diachronic study of sign languages

Sign languages seem not to be amenable to traditional historical reconstruction via the comparative method, making it difficult to replicate the successes achieved in the diachronic study of spoken languages. We propose to alleviate this difficulty with an alternative approach that draws upon nonarbitrariness and biomechanics, especially the drive for reducing articulatory effort. We offer a demonstration of this approach, which can add confirmation to known relationships between sign languages and new evidence in support of suspected relationships, helping to fill in a methodological gap in the diachronic study of sign languages.