Current problems with body powered hooks?

[Stephanie Lee Nickles]

Hi,

I am working with a small group of gifted and talented 4th graders who has selected the arm prosthesis as their research project to identify a current problem and design an innovative solution for it.

 

They have come up with some ideas to improve gripping with the body powered hooks.

 

If you can offer any current problems that people using these types of prostheses face with gripping, that would be great. We would love to learn more and hope to make an improvement in the technology.

 

Thanks,

Stephanie

[Daniel Ballarin]

being able to change the amount of pinch force is a problem. The most commonly used method is to just keep the tension off with a harness. however, to hold something like a styrofoam cup for long periods of time is nearly impossible. There was a great invention long ago called the Vector Prehensor that changed the angle of pull from the rubber bands to give a varied amount of pinch force. The problem arose with patenting.

[Wolf Schweitzer]

Current hook models that allow change of vector direction are the V2P Prehensor (Brady Veatch, ADA Technologies) and the Otto Bock Movohook 2Grip (I got three of these hooks, they were newly released after I had bugged them with revision ideas around June 2008, obviously something they were fast to build and sell but the product has not surfaced in their catalogs yet, probably also because it cannot be patented as that design was already patented decades back and that patent has run out long ago). The V2P is protected under current patents; if Otto Bock ever got their product to get patented is not known to me. - - Another point of controversy regarding the OB Movohook in my view is that their product description tags the hook joint "service free" but it does contain (we checked and fixed that) a plastic dish that grinds down over the period of a few months which causes a wiggle. Solution is to put a brass inlay there.

[Stephanie Lee Nickles]

Thank you for the feedback.