We represent a number of children who can't talk because of their disability and cerebral palsy due to a birth injury. And the child can usually communicate with his or her mother because the mom has been caring for the child for years and knows his or her needs and how the child feels and what the child wants, but how do you show tht to a jury in a medical malpractice case? Sometimes the jury will see the child briefly but usually there are doctors or expert witnesses who have examined the child and reviewed his medical records and treatment and can testify about his ability to feel pain.
The child may be taking pain medications or have some medical therapies addressed to pain. And the parents, brothers, sisters and care givers can usually tell when the child is in pain from his or her condition as well.
There is no one approach - all of these should be used to accurately and thoroughly show the child's pain in a medical malpractice case.