Effects of Upper-Limb Deficiencies on Infants

What effects does having an upper-limb deficiency have on an infant?

Typically the first two months of an infant’s life consist of sleeping, being fed and interacting with caregivers. Most upper-limb deficient infants during this time therefore do not seem to have any significant functional limitations and do not appear to experience any developmental delay. However, between the ages of 2 and 6 months, an infant begins to use his upper limbs to explore the environment as well as to achieve various physical milestones like rolling, holding bottles and lying propped up on their tummies. By 4 months, infants can usually play with objects in the midline of their bodies and by 5 months they can transfer toys from one limb to the other. Additionally, they may also stabilize an object using one limb while the other upper limb manipulates it.

Infants with upper-limb deficiencies may perform these activities by using their residual limbs and be quite successful reaching many of these typical milestones, albeit sometimes slightly delayed. For instance they may hug a stuffed animal with their forearms or use their residual limb to swing and hit mobiles that are placed near them. They may also prop themselves up on their normal limb and drag an object closer to them with their residual limb.

Even though most babies are not fitted with an initial prosthesis until the age of 6 months, some infants receive a passive prosthesis earlier. Often the terminal device of this early passive prosthesis is a mitt that parents can use to attach rattles or other objects, stimulating interest towards the infants’ affected side. This initial passive prosthesis may be covered with a soft pink or brown resilient plastic used to blend in with the rest of the upper limb and give it a better cosmetic appearance. The prosthetic socket that connects the prosthesis to the upper limb is usually constructed of a plastic-type material placed over a cotton sock and suspended onto the limb by a harness that wraps around the infant’s upper body. An elastic sleeve may be a better suspension device.

Using a prosthesis at this age may lead to some concerns. First, the prosthesis may need to be refitted frequently since the infant is growing rapidly during this time. Therefore, it is important the skin around the prosthesis be monitored often for signs of redness or irritation indicating abnormal pressure from a poorly fitting socket. The prosthesis may also interfere with some activities that the infant may do without a prosthesis, such as rolling over.

As an infant gets a little older he may be fitted with a voluntary opening terminal device. A voluntary opening device is normally forcibly held in a closed position but then can be opened by the parent. This voluntary opening device allows parents to place objects such as a rattle or other toy in the affected limb, which encourages the use of the prosthesis and allows the baby to become familiar with grasp on the affected side.