Nerve fibre masses / nerve fibre bundles that convey information (proprioception) to the cerebellum via the spinal cord about how the skeletal muscles of the lower extremity change their length, how much force they exert themselves, about how different joints are bent or stretched and about how quickly different movements are performed.
The posterior of the spinus spino-cerebellaris has its cell bodies in (starts from) the dorsalis nucleus in the gray matter of the spinal cord, runs uncrossed upwards in the lateral cord of the spinal cord and enters the cerebellum via the lower cerebellar arm. Once inside the cerebellum, the nerve fibers are distributed within both cerebellar hemispheres and contact, in the form of moss threads, both cerebellar nuclei and nerve cells (grain cells) in the cerebellar cortex.