Julie Hill: the research project
Many research teams have wanted to help people paralyzed by spinal cord injury by giving them implanted stimulators for FES. They have to consider the question: where should the electrodes be placed along the nerve? Many sites are possible from within the spinal cord to within the limb muscles.
The UCL team is unique in deciding to place all the electrodes on the nerve roots, which advantages and disadvantages. Julie Hill was one of the volunteers for our trial of the method. She had her implant in 1994 and first cycled in 1997. In between she gave us a huge amount of her time, mostly for standing tests and measurements in the Multi-Moment Chair. She described these tests as being as “exciting as watching the grass grow”. She was, and still is, the only person in the world to have shown that cycling is possible with stimulating electrodes on the nerve roots.
Electrodes can be placed on the skin (“surface electrodes”) to activate the leg muscles as shown when “Julie” is retraining her leg muscles (though the motion in the film is exaggerated). The advantages of using implants are:
• That the stimulator can be used for other functions – such as bladder and bowel – that are not possible from the surface, and
• That the electrodes are always ready, so the time-consuming attachment and removal is surface electrodes is unnecessary.
We like to retrain the muscles of people with spinal cord injury using surface electrodes before the decision is made whether to have an operation to implant a stimulator for leg function.