So, interesting and captivating - but what a poor premise! And, what's up with all jeans, can't he wear proper clothes - let m guess: is he, maybe, an INVENTOR? But the astounding frequency of usage of the word 'astounding' confirms that here, we get feelings, emotions, all riled up on a wooden stick. In reality, stress levels do build up, and prosthetic arms need to perform. They really do.

If 100 years ago, hooks worked as well as they still do - why does it now need to be forcefully be invented away?

Why is this one question painfully avoided by Dean Kamen as much as by all the beneficiaries of expensive overpriced myoelectric technology:

What makes a good terminal device? Why are hooks as useful as they are? What is great about body powered technology - because if it stayed popular for that long it cannot all be bad? What lesson do we learn from that?

So far I have not seen Dean or his representatives learn that lesson over any of the Luke arm presentations.

I wear TDs (terminal devices) such as both hands and hooks. And I measure the success of the prosthetic replacement by averaging my EODF (end of day feeling). And I would argue the following:

• This disability is primarily potentially and really stressful. Prosthetics helps only if it reduces stress.
• Prostheses can indeed reduce stress but for that, they need to be built and constructed specifically - that success is not a random event.
• Stress adds up from little bits of small problems.
• These can be individually assessed but I also think I can assess them on some type of average.
• If my stress relates to grips not working on a number of objects, I can try creating some type of geometrical 3D average shape of all the objects that I tried to grasp.
• I would statistically weigh the single objects by the frequency that I try to grab them.
• Then I would choose or build a single TD that best grabs that averaged object.
• In my experience, hooks are far more refined and better suited for many of these daily average grip situations than some of these hands.
• Body powered technology - but only if built well - is extremely powerful technology with regard to a number of concise issues.

It is laudable to see all that effort poured into building new and hugely expensive prosthetic hands. But the prosthetic has to primarily reduce stress - not primarily look like a hand or be expensive.

And I fear that a lot of that almost frantical effort to recreate human hands also comes from a poor technical understanding of what a simple popular and affordabe robust solution such as a hook *really* can do and does. And flawed initial premises may just not make for such great results no matter how big the batteries.

So far, the strength and simple power of the design-wise extremely refined Becker hands  as well as the V2P Prehensor (or the eventual Dorrance hook) do reduce far more stress for me than other TDs. I really love my Regal gloved Otto Bock hand for its pure and sweet Seventies' B-movie charm - but I'm not sure I'd upgrade to an Eighties' B-movie charm with that massive price tag.

For that money, I could buy and drive a VW Phaeton 12-cylinder car and still have bucks left - and that would surely boost my ego beyond any measure.