An 11 year old boy with only one hand was keen to start kayaking, and the problem was to make a safe (and easy release) attachment for the kayak paddle. He had a simple prosthesis provided by the NHS, consisting of a forearm sleeve terminating in a 19 x 1mm threaded stub.
A standard brass garden hose connector, with the O-ring seal removed, provides a rotatable but positive connection that is readily freed by a simple pull on the sleeve. The male part was connected to the prosthesis by a threaded brass adapter (see photo). A nylon bobbin was turned to be a sliding fit on the kayak paddle shaft, its position being constrained by two large O-rings that could be adjusted along the shaft. The bobbin was connected to the female part of the hose connector by a stainless steel yoke. This arrangement provides all the necessary degrees of freedom for use of the paddle. In the event of a capsize, the user can release the paddle by pulling on the brass sleeve with his free hand.
Bournemouth & District panel ref. 89/54