When writing technical papers I often write sentences like:
Where m denotes the proper mass of an object and c denotes the speed of light, the object's rest energy is given by E=mc2.
However I recently received a referee report claiming that this is poor and possibly incorrect usage. This surprised me, but it seems to be true that clauses starting with "where" that specify the meaning of notation more commonly appear at the end of a sentence rather than the start.
Is the usage above in fact incorrect? If I wish to retain the basic structure of (introductory clause specifying notation's meaning) followed by (statement in which the notation is used), is there a better way of formulating the introductory clause?