In humans, the rubrospinal tract is one of several major motor control pathways. It is smaller and has fewer axons than the corticospinal tract, suggesting that it is less important in motor control. It is one of the pathways for the mediation of voluntary movement. The tract is responsible for large muscle movement as well as fine motor control, and it terminates primarily in the cervical spinal cord, suggesting that it functions in upper limb but not in lower limb control. It primarily facilitates flexion in the upper extremities (see decorticate posture).
It is small and rudimentary in humans. In some other primates, however, experiments have shown that over time, the rubrospinal tract can assume almost all the duties of the corticospinal tract when the corticospinal tract is lesioned.