Someone has damaged a nerve. Perhaps because of a fracture, perhaps a fall, perhaps a complication of surgery they were told would be routine. They have read that electrical stimulation can help prevent muscle wasting. They have bought a device, often an inexpensive TENS unit, sometimes a consumer muscle stimulator. They have put the pads on, turned the intensity up as far as it will go, and nothing has happened. No contraction. No twitch. Nothing at all.

Then, usually near the end of the call, comes the question, and it is nearly always some version of this:

Could I have made it worse?

In physical rehabilitation, it is often the case that intensive effort is applied to exploit the natural ability of the body to adapt to the consequences of injury. This property, known as neuroplasticity is not yet fully understood but it at least represents hope that some functional recovery is possible in many cases. In many cases there will remain a functional deficit and ultimately we find ways to compensate for function that cannot be recovered.

The nervous system is a very complex, adaptable structure, that can be disrupted by illness or injury. Rehabilitation strategies to apply in a particular case obviously depend on the nature and extent of injury.

Clinicians might refer to an "upper motor" or "lower motor" lesion when discussing a particular case. What do these terms mean? In this article we review the meaning of these statements and the consequences for rehabilitation. Some of our electrical stimulation products relate to problems with the nervous system and may help to restore or compensate for loss of function following injury or illness. Which products are relevant to these types of lesions?

Let's start by reviewing some aspects of the nervous system.