Prehensor Grip for Children: A Survey of the Literature

A survey of literature was conducted on hand grip strength and grip strength with prosthetic prehensors of children 2 to 4 years old. The survey's purpose was to set grip strength requirements for a pediatric body-powered prosthetic hand. The survey included studies of grip strength in normal hands, grip provided by children's voluntary opening and voluntary closing prehensors and structural factors that enhance grip, such as friction, resilience and prehensor geometry. After comparing findings from studies in the literature survey, minimum grip force levels of 2 lbs. for 2- year-olds and 4 lbs. for 3- and 4-yearolds were incorporated into hand design specifications. Additional grip force, beyond the minimum, is considered highly desirable. Incorporation of grip-enhancement features into prehensor structures also is recommended.