The other option is changing your plan of care. Maybe you thought the innervation was good at first evaluation and focused on assisting with reducing mechanical issues in the joint. No progress, so you change to increase innervation through nueromuscular rehab. If you cannot find an effective method of progress you will discharge from PT. Examples may include stroke when innervation cannot be restored, osteoarthritis when joint mechanics are damaged, or periferal artery disease when blood flow is severely diminished. At the end of the day, utilization of ineffective treatment is unethical. But knowledge of systems at play will help you understand when you can be relevant to a patient's plan of care.