Spasticity is usually caused by central nervous system injuries, such as brain injuries or spinal cord injuries. Spasticity is a little different from stiffness.
Upper limb therapies and interventions have been well studied in cerebral palsy. Different interventions that have good evidence are Constraint Induced Movement Therapy (CIMT) and Bimanual Therapy. CIMT has been shown to be successful in children with hemiplegic cerebral palsy (CP). CIMT uses a splint to physically constrain the uninvolved arm and encourage them to use the more involved or affected arm.