  We introduce an alternative approach to the third order helicity of a volume
preserving vector field $B$, which leads us to a lower bound for the
$L^2$-energy of $B$. The proposed approach exploits correspondence between the
Milnor $\bar{\mu}_{123}$-invariant for 3-component links and the homotopy
invariants of maps to configuration spaces, and we provide a simple geometric
proof of this fact in the case of Borromean links. Based on these connections
we develop a formulation for the third order helicity of $B$ on invariant
\emph{unlinked} domains of $B$, and provide Arnold's style ergodic
interpretation of this invariant as an average asymptotic
$\bar{\mu}_{123}$-invariant of orbits of $B$.
