Day 4 of amputee awareness week.
4) UNEVEN SURFACES
I want you to give this some serious thought for a moment. Maybe read it over a few times.
Your ankle is a pretty clever (and important) piece of kit for keeping you upright and stable. Without having a clue how you do it, tons of muscles, bones, nerve fibres and connective tissue work together in harmony to give you constant feedback about the surfaces you are walking on. What type of surface, rough, smooth, slippy, sloped, jagged, uneven – if so which angles… and so on. This all happens in milliseconds and the signals are sent up your leg for the rest of the muscles to help out. Imagine your leg like a pendulum. Lots of corrective action has to happen down at the ankle and the further up your leg you go, the smaller the corrective actions have to be to keep you stable and stood up.
Now delete a foot and replace it with mechanics.
I had not even thought about this until I didn’t have one.. but you can even tell the type of surface and how slippy it is through your shoes. But you can’t when you don’t have one.
Back to the pendulum – and the picture here. My foot has to slip a long way before the feedback (at my knee) tells me it’s slipped. Way too late by then, I’m on the ground.
Add to that the uneven surface.. my prosthetic ankle js hydraulic and I have come to learn to feel for the socket pressure on the sides of my knee to know what way the ground is sloping.
Sounds hard? That’s because it is! Any amputee would prefer to walk on a flat, non cambered pavement any day! Take me off road and my brain is working overtime to compensate!