What is a primary consequence of poliomyelitis affecting motor neurons?

Poliomyelitis primarily affects motor neurons, particularly those located in the anterior horn of the spinal cord. When these neurons are damaged or destroyed by the poliovirus, it leads to muscle weakness because the brain's signals to the muscles cannot be effectively transmitted. Motor neurons are critical for voluntary muscle movement, so their impairment directly causes weakness and can result in paralysis of the associated muscles. This loss of function is most evident in the limbs, but can also affect head and neck muscles, depending on the neurons affected. Consequently, muscle weakness becomes a hallmark symptom of poliomyelitis due to the direct impact on the motor pathways responsible for voluntary movement.