Final answer:
Polio is the clinical condition affecting skeletal muscle caused by a virus. It is characterized by inflammation of the motor neurons and can result in paralysis.
Step-by-step explanation:
The clinical condition affecting skeletal muscle caused by a virus is Polio. Polio, also known as poliomyelitis, is a disease caused by an infection of the enteric poliovirus. It is characterized by inflammation of the motor neurons of the brain stem and spinal cord, which can result in paralysis.