a state of reduced or absent muscle tone (hypotonia), in which the muscles are soft, weak and almost do not resist passive movements. It usually occurs when the lower motor neurons, peripheral nerves, or the muscles themselves are affected, and occurs in conditions such as polio, peripheral neuropathy, spinal cord injury, or acute stroke with motor pathway involvement. Lethargy can be temporary, for example, at the initial stage of some brain damage, or permanent with irreversible causes. Treatment is aimed at eliminating the cause and conducting physiotherapy to preserve joint mobility and prevent complications.