fixed box size, we need only know the low-energy constants $g_A$, $g_{\D N}$, $\D$, and $f_\pi$ to remove this effect. Without twisting, one must rely on phenomenological or other fitting functions which introduce uncontrolled error. With twisting, however, the lattice practitioner can approach the calculation of the isovector magnetic moment from various ways in conjunction with the EFT. For example, one can choose values of $\th \sim 0.1$ to eliminate the need for a momentum extrapolation, *cf* Fig. \[f:mom\]. One must then use the EFT to remove the $\sim 25\%$ volume effects. Alternately one could choose $\th \lesssim \pi$ to minimize the effect of the finite volume. For these values of $\th$ one then uses the momentum dependence predicted by the EFT, *cf* Eq. , to obtain the magnetic moment. Another virtue to the EFT approach is that higher-order corrections to the quark mass, volume, and momentum-transfer dependence can be calculated to aid in the extrapolation. Although we have focused on the magnetic moment, the expressions we have derived here are also relevant for the isovector magnetic radius.

As a final point, an assumption inherent in our discussion is that no multi-particle thresholds are reached. For large enough momenta, multi-particle 