The electrical stimulationparameters used in the Odstock range of stimulators allows for nerve stimulation only, and is therefore unable to induce any movement in denervated muscles. This denervation would occur as a result of a lower motor neuron injury. As a rough guideline, this occurs in patients with a spinal cord injury of the level of L1 (Lumber 1) and lower. When being used in patients with a lesion higher than this, in order to achieve any sort of functional improvement, there needs to be some element of incompleteness to the clinical picture. In other words there needs to be some specific element absent from an already moderately functioning lower limb, or arm. The patients usually seen are those mobile using some form of walking aid already, and are perhaps using an Ankle foot orthosis to improve the walking by keeping the foot in a semi lifted position.
FESoffers an alternative to conventional treatment, encouraging active movement of the foot, and by constantly taking the foot through full range of movement with walking, avoids stiffening up of the ankle. Improvements are reflected in objective tests, recording the speed of walking and the effort of walking by measuring the heart rate. Common reports are of walking being made easier, quicker, and safer, with patients feeling a lot more confident in walking about. Carry-over of these improvements is often found when looking at unstimulated walking too, indicating a training effect of stimulation. Other improvements are also found in decreasing calf tone and improving range of movement, and peripheral circulation. Improved standing symmetry is also encouraged due to the nature of the foot switch-stimulation relationship.
Two channelsof stimulation are also used at times, in order to integrate another set of muscles into the walking pattern. This might include the hamstring muscles to improve the knee bending when bringing the foot forwards, or to the gluteal muscles to bring the body over the effected leg when standing. The quadriceps muscles may also be stimulated to improve standing stability.
Functional Electrical Stimulation relies on the presence of some residual activity or function, which it can then augment to improve independent function. This is possible for walking, as described in the person with an incomplete Spinal Cord Injury.
The activity of FES Assisted Indoor Rowing can be achieved in Complete SCI. Other FES applications include:
- FES Assisted Cycling
- FES Assisted Standing