Spasticity is usually caused by central nervous system injuries, such as brain injuries or spinal cord injuries. Spasticity is a little different from stiffness.
One of the things that was identified through research is that patients with cerebral palsy have higher rates of depression and anxiety than you would see in the general population.
Let me tell you about multimodal communication. We, as typical communicators, all use many different strategies. We use speech, gestures, facial expressions, technology, and no-tech solutions. As communicators, we all size up the situation based upon our communication partners, the context, the environment and then we choose to use the most effective communication strategy.