The problem is that you can’t comfortably anchor it to the body in a way that lets you put so much force on it. Putting weight on an amputation stump hurts.
Exoskeletons, on the other hand, are in development. They have working ones, but they don’t work well enough for general use yet. And there’s the problem of safety: you need to make sure you don’t exceed the limits of the user.
We’re not really close to the point where any prosthetic is an upgrade on any human limb. Prosthetics you can control with your mind do exist, but are severely limited compared to human limbs. I’ve yet to see any prosthetic that’s stronger than a human limb.
There are two big limitations to consider:
- Even if you could attach a more powerful machine to a person, the attachment point is always going to be the weak point.
- How do you power it? Battery technology just isn’t there yet. You’d be lucky if you got 2hrs of super arm followed by several hours of charging.
I’m no expert, but I do have an interest in prosthetics and have been following the news and have seen lots of conversations that have no solutions for those two problems.
the main benefits from prosthetics are usually due to properties that the prosthetic have that a normal limb wouldn’t have (or vice versa) - like specialized prosthetic limbs for rock climbing
still, I would expect most people would be able to use a tool in lieu of a prosthetic … still, the absence of a limb might be advantageous in some situations (even if obviously a downside in others).
If I remember correctly, I think another major hurdle is the feedback loop part (prosthetic inputs to neural connections). We have some relative understanding of having machines to act in how we intend, but without that loop, still leads to a lot of errors. I don’t mean full simulation of the sensorium to mimic having your arm back, but the minimal amount necessary for fluid movement without conscious visual monitoring.
