Evidence from pulsar wind nebula symmetry axes and radio polarization observations suggests that pulsar motions correlate with the spin directions .
We assemble this evidence for young isolated pulsars and show how it can be used to quantitatively constrain birth kick scenarios .
We illustrate by computing several plausible , but idealized , models where the momentum thrust is proportional to the neutrino cooling luminosity of the proto-neutron star .
Our kick simulations include the effects of pulsar acceleration and spin-up and our maximum likelihood comparison with the data constrains the model parameters .
The fit to the pulsar spin and velocity measurements suggests that : i ) the anisotropic momentum required amounts to \sim 10 % of the neutrino flux , ii ) while a pre-kick spin of the star is required , the preferred magnitude is small 10 - 20 \mathrm { rad s ^ { -1 } } , so that for the best-fit models iii ) the bulk of the spin is kick-induced with \bar { \Omega } \sim 120 \mathrm { rad s ^ { -1 } } and iv ) the models suggest that the anisotropy emerges on a timescale \tau \sim 1 - 3 s .