Wave Running Considerations

Wave Running Considerations

John Spaeth

6/14/1999

Don,

Here are some thoughts:

Wake boarding (wave running) is just like water skiing except the boat
speeds are somewhat slower. Your client's prosthesis will have to be
immersed in water and so components will have to be selected based on
minimal corrosion. There is no need for a multiaxial foot, but the foot
will need to provide a solid stable base and fit firmly in the straps on the
board w/o twisting about. Possibly a Seattle Lite or similar which is solid
rubber with composite keel to minimize the effect of water damage.

Both knees will have to flex beyond 90 Deg. while waiting in the water, and
remain flexed at about 15-20 Deg. while wake boarding. A silicone suction
sleeve would not be inappropriate. Neither would a pin lock system, however
I would avoid aluminum because of the corrosion. Also consider full suction
perhaps with air expulsion if you feel comfortable with that suspension at
your clients relatively short amputation level. I lean more to the pin lock
because it would be easier to get off in an emergency, which brings me to my
next point.

You must consider, and make provisions for a break away feature for the foot
straps on the board. Make sure the straps can break away if put under a
twisting load. An anatomical foot will slip out of the straps on the board
a prosthetic foot will not. It is important that your client can leave the
board with minimal difficulty. This may entail adding Velcro or snaps to
the straps on the board. This is not only important for emergency release,
but in the natural course of wake boarding the foot must easily be able to
slide in and out of the board straps. The feet must slide into the board's
straps while the individual is lying on his back in the water. And the foot
must fit tight enough into the strap so it will not slide out on its own.

I would suggest donning and doffing the board in a swimming pool as practice
while you are present. Sculpting the posterior of the foot will aid in this
process.

Don't forget to cover the effects of immersing a prosthesis with your
client, and a spray on coating of Krylon to all metal components will
drastically minimize the effects of corrosion.

Water sports are great reasons to use monolithic prostheses, too bad we
don't have one with the structural integrity needed for high activity
individuals. This would be a great opportunity for the cad-cam and
injection molding industries to synergize with prosthetics.

Regards
John P. Spaeth CP