I have had a phone app with a neurologist about pains up and down my legs and arms, they said they would send me for tests were they will put things on my toes to see if the signals are going the right way, could you try and explain this please?

Sounds like this could be an EMG. An EMG tests peripheral nerves, from the spinal cord to the "tips of the toes", to determine if there is a nerve etiology to your symptoms. It is performed by a physician and gives immediate results.

Since basic data provided is scanty, might assume that the neurologist wants to exclude a peripheral neuropathy and by testing nerves and muscles utilizing EMG/ NCS approach, large fiber neuropathy might be uncovered. The test does use mild electrical shocks and needles to find whether normal or abnormal function is present.