All people with Cerebral Palsy have damage to the area of the brain that controls muscle tone. As a result, they may have increased muscle tone, reduced muscle tone, or a combination of the two (fluctuating tone). The parts of their bodies which are affected by the abnormal muscle tone depends upon where the brain damage occurs.

Hypotonic cerebral palsy is generally characterized by low muscle tone, resulting in floppy muscles. The instability of muscles can cause children to miss important developmental milestones such as rolling over, sitting up, crawling, and walking.