Wrist Rotator for the Child-Size Hand

RINCHEN DAKPA, CP(C)*Toronto, Ontario


The bilateral amputee, particularly above-elbow, cannot preposition the artificial hand other than by unattractive, tiring body movements. Using the feet for feeding and writing is unacceptable for adolescents and likely to cause development of scoliosis.

Consequently, the Swedish hand was modified to accept the Otto Bock quick-disconnect wrist unit and rotator. Components are disassembled to the base plate of the hand chassis. The hand-frame mounting brackets are removed and the surface made level. A slot is machined from the cable-outlet hole to the edge of the chassis. Four holes are drilled so the wrist unit can be secured to the hand. A wrist rotator housing is fabricated so that the powered rotator and the lamination collar can be installed. Wiring is fed from the coaxial plug into the cable hole in the chassis and secured. The wrist unit is reassembled. If the hand is to be controlled myoelectrically, wiring from the coaxial plug is connected to the electronic package of the hand. If the hand is to be controlled by microswitches, wiring is connected to the motor. The total cost of modification is Canadian $880.80, including three hours' labor.

*Ontario Crippled Children's Centre, 350 Rumsey Road, Toronto, Ontario M4G 1R8 Canada