Final answer:
The middle three toes are primarily innervated by the L4 and L5 spinal nerves, with the second and third toes receiving innervation from L4 and the fourth toe from L5.
Step-by-step explanation:
The root value dermatome for the middle three toes is considered to be primarily supplied by the L4 and L5 spinal nerves. Dermatomes are areas of skin supplied by sensory neurons that arise from a spinal nerve ganglion. Specifically, the fourth toe is typically innervated by the L5 nerve root, while the second and third toes receive innervation from the L4 nerve root. It is important to note that there can be some variation between individuals in the exact cutaneous innervation of the toes.