There are multiple factors that impact bone health, including birth weight, nutrition, medications for seizures and/or reflux, genetics, and physical activity. Targeted exercise to improve bone health in childhood can be sustained into adulthood, and childhood is the best time to promote bone health.
Spasticity is usually caused by central nervous system injuries, such as brain injuries or spinal cord injuries. Spasticity is a little different from stiffness.
I have cerebral palsy spastic diplegia. So it affects my legs and sometimes my fine motor skills. I walk with two canes. I do things a little slower, but I get things done.
One thing that parents can say to start a conversation with their kids is, "Let's talk".