Complex sentence: Hoffman's sign involves a monosynaptic reflex pathway in Rexed lamina IX of the spinal cord, normally fully inhibited by descending input; the pathways involved in the plantar reflex are more complicated.
Split into simpler sentences: Hoffman's sign involves a monosynaptic reflex pathway in Rexed lamina IX of the spinal cord, normally fully inhibited by descending input. The pathways involved in the plantar reflex are more complicated.