isometrics (n.)

1838, literally "of the same measure," from iso- "the same, equal" + -metric. The components are Greek: isos "equal, identical" + metron "a measure." Originally a method of using perspective in drawing; later in reference to crystals. The physiological sense relating to muscular action is from 1889, from German isometrisch in this sense (1882).

in the names of sciences or disciplines (acoustics, aerobics, economics, etc.), a 16c. revival of the classical custom of using the neuter plural of adjectives with Greek -ikos "pertaining to" (see -ic) to mean "matters relevant to" and also as the titles of treatises about them. Subject matters that acquired their English names before c. 1500, however, tend to be singular in form (arithmetic, logic, magic, music, rhetoric). The grammatical number of words in -ics (mathematics is/mathematics are) is a confused question.