The story I am currently writing is one set in a future where it's rather common for people to have various cybernetic enhancements. While often they are intended to replicate the form and function of their biological counterparts they are also frequently used for the purposes of direct enhancement, meant to be as powerful/efficient as possible. That of course begs the question - do your bionic feet really need toes? Is there a reason to include toes rather than make the foot a big block, as it were? I assume modern leg prosthetics like the "foot blades" that is the Flex-Foot Cheetah mostly look that way because it's a much simpler device to make than the intricate structure that is our legs and feet, while offering a desired result (running/jumping capacity). But they work well, even without toes. Assuming we make bionic legs, would the feet need toes, or are there more efficient ways of doing it? (similarly it's worth asking, do we need all our fingers? We naturally need grippers but are there distinct advantages from having 5, compared to 3 or 4 - 3 fingers in a "tripod" setup could work in many cases, no?)
I would say if they're already bionic, no, they don't need toes. We use our toes for balance. Even losing one can change the way someone walks. As for fingers, we need as many as we can function with. I'm sure if you took away the middle finger and pinky, we could function just fine. But take away the thumb and pinky, and we'd be in big trouble. lol
You need a ground attachment mechanism with inherent flexibility otherwise you are going to destroy your movement mechanism. The toes are made up of multiple joints, that form a continuous "spring" from toenail through the foot / achilles / calf / hamstrings. This is actually replicated with the blades in use by Oscar Pistorious, as an example, without all the fiddly bits in between. If you just had blocks you would 1. lose traction 2. lose suspension / shock absorption If you want to see this in action, the simplest experiment is to get a single sheet of paper, place your hand on it then 1. form your hand into a solid and try to "flick" the paper backwards = towards yourself - you are restricted to shoulder --> elbow --> wrist --> finger tips 2. allow your hand to move naturally and try to flick the paper again - you should now be able to flick the paper quite forcefully with minor shoulder|elbow|wrist, but significant flexible finger movement Your feet operate in a very similar fashion. You need toes and / or a flexible ground contact point, assuming you want to move faster than a hobble. HTH Check out DARPA dog for how they do it with their robots there. The flexibility is inherent in the rubber "feet" and you can see the spring effect through the legs.
The foot blades are for movement, but for flexibility or for say climbing, or using grip you would need toes. They also serve as balance, and for pivoting. I would say yes, you need toes. Also if you haven't check out the deus ex machina games/ universe, similar ideas and thinking. They have toes in their prosthetics in that game i think.
The second best aspect of my climbing shoes is that the toe box -- from mid foot forward -- does not bed at all. Not one bit. It's as if I do not have toes. The best aspect is that they are made of rubber -- they practically stick to the wall. I wonder if you do in fact need toes to climb, vs a synthetic but incredibly "sticky" compound for grip. And by sticky I don't mean honey, I mean rubberised.
I think you've answered the question yourself, though, haven't you? We have toes as a the end product of a long chain of events that starts with certain kinds of fish having first cartilaginous and then boney support spikes (rays) in their fins, not because toes are inherently the best or the only way to balance a creature whose body is more vertical than horizontal. In fact, you can easily see that humans are one of just a handful of creatures with toes that answers to this particular need. Nearly all other vertebrates have horizontally aligned bodies with ventral facing appendages. You don't need toes to balance, but you do need something to do that job.
Toes are for balance so if your mech-legs have a way of balancing themselves in a different way then they don't need toes.
Wreybies post triggered a link back to the Gingercoffee post. Here's a bionic foot: Here's the fin of the walking fish. It might just be me but they look remarkably similar where the "foot" makes contact with the ground.
