An infant with an upper-limb loss or absence presents uncertainty regarding how the deficiency will impact the ability to function physically and psychosocially in life. A decision needs to be made if and when to fit the child with an upper-limb prosthesis. Literature indicates that early prosthetic fitting of a unilateral transradial limb deficiency is a strong indicator of a child's continued wear of a prosthesis later in life, whereas fitting a child at an older age is more likely to result in a rejection of the prosthesis. The increased acceptance of an upper-limb prosthetic device by early fitting may be explained by a perspective that has not been addressed extensively in the literature. This perspective is that fitting an infant with an upper-limb prosthetic device both affects and is affected by brain development. It is important to understand that the timing of fitting should correspond with the appropriate developing activity in the child's brain. The purpose of this article is to illuminate how science of brain development informs the timing and device design when fitting a child with an upper-limb prosthesis, thereby establishing a successful protocol for prosthetic fitting.
Brain and grasp development literature is reviewed to explain how sensory and motor experiences help neural connections to be made within the brain during critical periods of development of a child's life. The knowledge is used to explain why it is important to fit a child early in life with an upper-limb prosthesis and to inform the clinical team what type of prosthesis should be fitted during different stages of development.
A protocol for successful early prosthetic fitting was developed that takes advantage of a child's different and developing abilities at the various stages of brain and motor development.
Neurodevelopmental principles explain how neuronal connections are created when a child's brain is most receptive to environmental input. A child's use of motor skills to interact with the environment leads to cognitive, social and emotional development. Brain development studies, therefore, support early upper-limb prosthetic fitting. Because the development of grasp and the use of both hands together to manipulate an object is a progression, the timing of prosthetic fittings to match the needs of the developing brain is critical. Fitting an infant with a passive prosthesis and then soon transitioning to a myoelectric prosthesis allows the child's brain to incorporate the active prosthetic grasp into the child's motor planning and movement execution. Children as young as 12 months of age have shown the ability to control a myoelectric hand in contrast to an inability to control a body-powered terminal device until an older age. By fitting a child during the first 2 years of life with a myoelectric prosthesis, the time of rapid brain development while grasping ability is being established is not missed. Studies on brain development therefore support early upper-limb prosthetic fitting and provide a framework for a successful prosthetic fitting and treatment protocol.