Most commentators apply the phrase ‘vitans onus…iugi’ not only to the heifer but to Attis himself. When they ask what iugum Attis is avoiding, the immediate context provides no obvious answer. They are therefore compelled to interpret the iugum either in the light of a much earlier passage or in the light of a much later one. Neither procedure is satisfactory.
On the other hand, at least one editor has proposed that the phrase ‘vitans onus…iugi’ does not apply to Attis himself but to the heifer alone. The comparison between Attis and the heifer then lies only in their frenzied speed; the yoke-avoiding action is external to the comparison and merely heightens the picture of the charging heifer. The obvious difficulty with this view is that the concept of a yoke, and more generally of avoiding servitude, plays an important role relevant to Attis later on in the poem. From line 50 onwards Attis sees himself as an erifuga anxious to escape from slavery to Cybele. And the account of Cybele's lion, sent to round him up, twice refers to the notion of freeing from a yoke (76 and 84).
Both these traditional approaches concentrate on the literal meaning of the phrase vitans onus…iugi: they assume that the yoke itself is important and that it either does or does not make sense when applied to Attis. But if we focus instead upon the action which the whole phrase vitans onus…iugi suggests, then the description of the heifer has an apt application to Attis within its own immediate context.