The development of sensorimotor mechanisms involved in the control of grasping demonstrate a rapid development during the first years in typical developing children. There is an almost adult like patterns at 6-8 with short delays between movement phases and a parallel increase of grip force and load resulted in a grip-lift synergy. This grip-lift synergy in poorly developed in children with cerebral palsy (CP). In general, they display prolonged delays between movement phases, a sequential onset of grip force and load force, resulting in an immature or absent grip-lift synergy even at 6-8 years of age. Although there are large developmental differences, little is known about the developmental processes underlying hand function during subsequent development in children with CP. In a 13 year follow up study we have investigated the development on manual ability during functional tasks with clinical and experimental data. The children improved both in terms of speed and movement efficiency. This suggests that improvement in hand function occurs over a longer time frame than commonly would be expected. This occurred despite the heterogeneity found in this CP population, suggesting that the developmental changes are robust, although small. The improvements in hand function during development provide further theoretical basis for providing intensive practice.