It sometimes seems that techniques that we use have not changed much during my 30 years of practice. It is similar with other areas of medicine and surgery, where lower limb amputation techniques have not changed much in 100 years, and the idea of bionic feet was something we saw on TV in the 1970’s.
The last 10 years, since the introduction of the iPhone, have seen huge changes in the way that technology becomes a part of everyday life. We have come to rely on Apps for many of the most basic things that we used to do automatically.
25 years ago I used to be amazed at how many phone numbers most people knew off by heart. I’m sure, if you are old enough, that you knew random strings of numbers associated with your close family and friends, work, doctor, taxi, school, team coach, etc. Perhaps you still remember some of them! Since mobile phones became popular there has been no need to use that part of our memory, because the phone stores and remembers those numbers.
Similar changes have come about with addresses and directions. Mapping Apps have taken over the need for us to remember where we have been, and how to get there (or home again).
Whilst these technologies are useful, and time saving, they also turn out to be somewhat reductive in affecting our natural ability to use our memories and spatial awareness.
Now phone numbers and directions are one thing, but imagine if you forgot something fundamental, like how to walk.
The mid 1990’s started to see home computers becoming more common. They were expensive, but exciting, because of the opportunity to access the World Wide Web.
About the same time, young soldiers were recovering from the injuries of the first Gulf War, and were becoming aware of the possibilities that personal computers presented. The ability of a computer to control a robot arm (as used in manufacturing) was well known, but what if one day it could control a human prosthesis? At that time the size of the components, the speed of the computer, and the battery technology meant that these ideas were possible in theory, but had no practical use.
Some of these Veterans in the USA went to University and helped develop the first motorised limbs, which became a reality around the mid 2000’s. These devices were still autonomous though, and relied on internal sensors to detect speed and tilt in order to activate the motors. The amputation procedure was still the same, with a stump and socket arrangement to attach the prosthetic. Whilst it was technologically advanced, it was still attached only to the limb, and required extensive brain retraining to activate the muscles for a natural gait.
It was possible that with nerve and muscle damage, you could forget how you used to walk, and train yourself to move differently.
This exciting development means that with the help of electrodes, and some modification of the amputation procedure, there can now be two-way communication between a prosthetic limb and the brain of the user.
What’s more the sense of proprioception, or knowing where your foot is in relation to the rest of your body, is returned.
You know how we used to remember phone numbers without thinking, just like we remember how to walk. The ability of our bodies and brains to re-train when circumstances change is phenomenal.
The possibilities presented by this technology and new surgical techniques are likely to mean a real reduction in the complications associated with traditional prostheses. Adverse changes to gait, balance and shock absorption could be reduced, and the incidence of painful foot and ankle arthritis will be zero!