Segmental projection from muscle spindles: a perspective from the upper cervical spinal cord.

The segmental connections of muscle spindle afferents originating from primary endings do not follow the same pattern at all levels of the spinal cord. This review is concerned with the characteristics of neck muscle spindle projections, which illustrate several differences between their segmental organization and the arrangement of hindlimb muscle spindle afferents in the lumbosacral spinal cord.