The principles established in Parts I to III apply broadly to denervated muscle wherever it occurs in the body. But clinical reality is not broad; it is specific. Talking about a denervated muscle may have seemed abstract, but now is the time to focus on specific conditions that cause denervation.
A facial palsy presents challenges that a thigh muscle does not. A spinal cord injury involves complications that a post-surgical nerve repair does not. And the practical question of combining electrical stimulation with other rehabilitation treatments, such as standing and spinal cord stimulation, requires guidance that general principles alone cannot provide.