Why does paralysis affect hind limb(legs) but not forelimb(hands) within polio patients?

The arms and other muscles can be affected by the polio virus, it's basically that the legs are more common. It probably have to due with the reality that the virus attacks the anterior horn of the spinal cord, mostly the area that controls lower extremity motor function.
The paralysis is usually asymmetric and simply during the febrile phase of the disease. About 2/3 of the people artificial with paralysis enjoy residual neurologic damage. Paralysis surrounded by polio only occur in almost 5% of the time.