  We study the orbital angular momentum contribution to the spin structure of
the proton. It is well known that the quark and gluon spin contributions do not
add up to the proton spin. We motivate the connection between the Generalized
Transverse Momentum Distribution (GTMD) $F_{14}$, and orbital angular momentum
by exploring the underlying quark proton helicity amplitude structure. The
twist three Generalized Parton Distribution (GPD) $\tilde{E}_{2T}$, was shown
to connect to OAM. We study these functions using a diquark model calculation.
The GTMD $F_{14}$ is unique in that it can describe both Jaffe-Manohar and Ji
OAM depending on choice of gauge link, i.e. whether final state interactions
are included or not. We perform a calculation of $F_{14}$ in both scenarios.
