A loader boom arm for a material handling vehicle used in the agricultural or construction industries includes a post attachable to the vehicle, a lower arm pivotally connected to the post, an upper arm pivotally connected to the lower arm, a pivoting mechanism coupled to the post and the lower arm, and a link arm pivotally connected to the post and to the upper arm. The boom arm is raised and lowered in an angular direction of rotation by pivoting the lower arm about the post using the pivoting mechanism. As the lower arm is pivoted, the link arm causes the upper arm to pivot relative to the lower arm such that the upper arm pivots further in the direction of angular rotation than the lower arm, thus changing the angle between the lower arm and upper arm. The boom arm also preferably includes a low profile self leveling linkage assembly for maintaining the levelness of a bucket during raising and lowering of the boom arm, having a control arm pivotally connected to the lower arm, a rotator link pivotally connected to the upper arm at a leveling fulcrum, and an output arm pivotally connected to the rotator link and pivotally connectable to a work implement. The subject loader boom arm allows an operator to move material in a bucket attached to the boom arm to locations of higher elevation and further reach than typically available with conventional boom arms.