  In this work it is shown that dynamical quantum phase transitions in
Loschmidt echos control the nonequilibrium dynamics of the order parameter
after particular quantum quenches in systems with broken-symmetry phases. A
direct connection between Loschmidt echos and the order parameter dynamics is
established which links nonequilibrium microscopic probabilities to the
system's macroscopic dynamical properties. These concepts are illustrated
numerically using exact diagonalization for quantum quenches in the XXZ chain
with initial N\'eel states. An outlook is given how to explore these
predictions experimentally with ultra-cold gases in optical lattices.
