It does not take very much for your body to get paralysed. The trigger for motor functions originates in what is called the motor cortex in your brain. This signal then travels through your spinal cord to the different parts of your body to create movement. My fingers for example are being guided by my motor cortex as I type this article. In the event of an injury to this pathway, while the trigger for motor function remains, its transmission to the various parts of your body shuts down leading to the inability of your body to move itself. This can be traumatic to say the least.
In a stunning experiment, scientists have found a way to trigger this motor response in the lumbar region bypassing the area of the spine that was injured. In order to this do, two sets of wireless electrodes were implanted. The first in the brain to detect the trigger of motor responses through a spike in electrical activities and the second in the lumbar region to stimulate the muscle group to respond. The signal from the first set was sent to an external computer which then triggered the second to act. What was fascinating was that there was no training or conditioning required and as soon as the switch was flipped, the patient was able to get on a tread mill and walk. Success at creating motor responses had led scientists to believe that much more complex brain-machine processes could be developed to control different aspects of human activity. Who knows, they may even find the “switch off” button.
More seriously, going forward, it may be possible to create motor functions entirely from external sources for patients who suffer from various cognitive diseases such as Alzheimer’s and Parkinson’s in which motor functions get impaired. Oh by the way, the patient was a monkey but its a small leap from monkey to man.