  While twist-2 GPDs allow for a determination of the distribution of partons
on the transverse plane, twist-3 GPDs contain quark-gluon correlations that
provide information about the average transverse color Lorentz force acting on
quarks. As an example, we use the nonforward generalization of $g_T(x)$, to
illustrate how twist-3 GPDs can provide transverse position information about
that force.
