USE OF COLOUR MAPS AS A DISCRIMINATOR BETWEEN LBP AND NON-LBP SUBJECTS

Introduction

Previous work(1) has suggested that Spectral Colour Mapping (SCM) may have potential as an objective measurement tool for analysing Electromyography (EMG) data from spinal muscles, but the production and analysis of these maps is a complex undertaking. It would be beneficial for a system to create these maps and be useable with a minimum of training.

Methods

EMG data was recorded from 192 subjects across two years (initial contact, 12 months and 24 months). The data were analysed and SCMs produced. The 30 second test data was split into 30 one second epochs. Colour values were scaled to the individual data set maximum and divided into 12 bands according to frequency strength at a particular point. Median Frequency values were calculated for each epoch and a line of best fit added to the colour map to further aid the diagnosis process.

Maps with faulty recordings were excluded and 20 data sets from each group (BP and no BP) selected at random. Four observers were given only 5 minutes instruction and then asked to indicate whether they thought each map belonged to the LBP or no LBP group.

Results

The results ranged from an accuracy of 72.5%, down to 40%. These figures were closely correlated to the experience level of the observer in question. This would suggest that improving and extending the instruction period would improve these outcomes.

This test is to be repeated in two months after the observers have completed additional training, the results will be demonstrated at the meeting.