ergonomist

Concise Oxford English Dictionary © 2008 Oxford University Press:
ergonomics /ˌəːgəˈnɒmɪks/

▶plural noun [treated as sing.] the study of people's efficiency in their working environment.

– derivatives
ergonomic adjective,
ergonomically adverb,
ergonomist noun.

– origin 1950s: from Gk ergon ‘work’, on the pattern of economics.