Aims

To investigate whether the duration of pain has an influence on the clinical outcomes of patients with low back pain (LBP) managed through the North East of England Regional Back Pain and Radicular Pain Pathway (NERBPP).

Background

The BACK To Health programme is part of the wider North of England back pain and radicular pain pathway. The purpose of this programme is to provide a CPPP approach based on the NICE guidelines CG88 for those with back pain that has not responded to early management and simpler therapies. The purpose of this study is to present preliminary results of this programme.

Introduction

ECG contamination of paraspinal EMG measurements is a known issue ^(1,2), with several proposed methods of correction^(3,4). In addition to this some question remains to how much of an effect this contamination actually has on the EMG recordings.

Background

Doubt has been cast over the accuracy of dermatome charts. This study investigated a large group of patients with known lumbar nerve root compression (NRC), and identified whether their radicular pain corresponded with the predicted distribution on a dermatome chart.

Introduction

It has previously been reported ^(1,2,3) that EMG signals from the lumbar spine are highly prone to contamination by ECG artefacts. It has also been reported that Independent Component Analysis is a suitable method for extracting this contamination (4).

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.

Background context: It is frequently stated that referred pain does not travel below the knee. However, for many years studies provoking referred pain have demonstrated pain radiating below the knee.

Methods: Over a twelve month period, 643 patients with mechanical back pain and 185 patients with nerve root compressions were seen. For each patient two body map images (front and back) were obtained. Some patients attended for review, at a minimum of six weeks after their first visit. These images were also analysed.

Composite images were created by combining all images from patients in one diagnosis group. Colour based overlays were used to analyse the body map images, to locate the locations of pain. Colour density was scaled so that the site with the most hits had a pure colour, reducing down to zero colour for sites with no hits.

Results: There were 720 nerve root compression images. 216 (30%) showed no leg pain, 91 (12.6%) showed upper leg pain, 134 (18.6%) showed lower leg pain and 279 (38.8%) showed upper and lower leg pain.

There were 1964 mechanical back pain images. 674 (34.3%) showed no leg pain, 528 (26.9%) showed upper leg pain, 308 (15.7%) showed lower leg pain and 454 (23.1%) showed upper and lower leg pain.

Conclusion: A large proportion (39%) of the mechanical back pain images indicated that the patient experienced referred pain below the knee. This has significant implications in the diagnosis of nerve root compressions, potentially leading to inappropriate surgery.

Conflicts of Interest: None

Source of Funding: None

Introduction: It has previously been reported(1,2,3) that EMG signals from the lumbar spine are highly prone to contamination by ECG artefacts. As the ECG spectrum overlaps an area of interest in the EMG spectrum this has obvious implications for the accurate analysis of EMG data.

Methods: EMG data was recorded from 192 subjects across two years (initial contact, 12 months and 24 months). When a moving average filter was applied to this raw data an obvious ECG trace could be observed in the case of a large proportion of the tests. The application of a Fast Fourier Transform on this raw data demonstrated a large low frequency spike, with little known correlation to lumbar muscle spectral characteristics, but highly indicative of an ECG signal.

As multiple source signals were recorded per test, the Independent Component Analysis technique was able to be used to split the EMG raw signal into statistically independent components. This technique is designed to take the multiple signal inputs, and convert them into multiple outputs, where the inputs are distinguishable by electrode location; the outputs are distinguishable by signal biological origin.

Results: Upon extraction, one of the signal traces showed a clear ECG trace. The Fourier Transform of this trace showed the low frequency spike, with no other signal components present. The Fourier Transform of the EMG trace showed the original EMG graph, with no low frequency peak. Specific spatial information has been exchanged for a much cleaner signal.

Conflicts of Interest: None

Source of Funding: None

Introduction: The delivery of healthcare in the 21st Century is based on evidence based practice with an increasing call to listen to the voice of the patient this research was conducted to identify patient views on this topic.

Methodology and Results: A cross sectional descriptive postal survey on patients with mechanical low back pain from 2006. Analysis was conducted statistical for quantitative data and thematic analysis (Burnard 1991) on qualitative data.

The reality of living with back pain was considered and patients were asked to rate the interference in aspects of Activities of daily living (ADL). They were then asked which type of support or encouragement they would find useful and how this should be provided. The effect of living with back pain was evaluated using PPMCC in relation to limitation to ADL against age, gender and exercise with no statistical significance demonstrated. However comparison was conducted with employment as a variable against pain on average day (r = −0.155 n=135) satisfaction (r= −0.153 n =132) expressed need for support (r = −1.05 n = 114). The question as to what style of support was clearly defined by the patients this was graphically analysed, demonstrating times and locations they would prefer.

Conclusion: There is opportunity to use this data as part of the recommendations in current discussions with PCT colleagues on the local spinal pathway. The re-shaping of services will then include expressed views and preferences of patients.

Introduction: In the current political climate ensuring the correct information is distributed to the correct recipient is of paramount importance. Clinical departments often find themselves needing to provide information in order to educate the general public regarding general clinic information and the procedures it carries out.

Methods: The Spinal Assessment Clinic (SAC) at the James Cook University Hospital consists of a multi-disciplinary team. As a result of this many treatment options are available to patients attending the clinic. Due to the necessary time constraints in the SAC, a system was required to help educate patients and the general public about the various diagnoses and the treatments available.

This information was provided by the specialist nurses and orthopaedic surgeons within the SAC team. A multi-portal website was created to allow patients easy access to this information: and to also allow, the information to be updated as and when needed. A facility was also included to allow the provision of external resources that would be of benefit to the patient.

Results: Initial feedback showed that this provided an effective means of achieving the established goals. An online rating system was implemented which currently allows visitors to grade articles along with optionally leaving feedback. This will be presented.

Purpose: Low frequency peaks (LFP) commonly observed in EMG spectra of paraspinal muscles. These peaks have frequency of 11–15Hz (Median=13, SD=4) and commonly observed in 40% of EMG recordings. We examined the correlation of these peaks with variation in within individuals change in load, between individuals load, gender, age, history of back pain and HW.

Methods and results: Nineteen healthy volunteers were recruited for study of within subject variation in load and data from 106 subjects was examined for the remaining analysis reported here. EMG acquisition was performed using the method described by Oliver et al (Oliver et al., 1996) at a range of load varying from a kilogram to 100% MVC in increments of 10% MVC. The tests were performed in a random order. This method was used for acquisition of data from the second group (n=106) with an exception that only one load fixed at 2/3MVC was used. All parameters including Low frequency peaks and Half Width (HW) was calculated by an automated software developed for this purpose

No correlation between within individual change in load and presence or absence of LFP was found. Only one subject showed a significant correlation between individual change in load with the magnitude of LFPs (r=−0.75, p=0.012). However, when the cumulative data from all 19 subjects was analysed, small correlation between the change in load and magnitude of LFPs (r=−0.17, n=187, p=0.022) was observed, with greater load associated with smaller LFP. No other correlation between gender, individuals load, age and fitness was found.

Conclusion: The appearance of the LFP has been previously described. As yet the underlying cause is not understood, but may be related to a load/feedback loop. The results of this study suggest that load is a factor that may affect LFP and this should be taken into consideration when methods such as HW are used.

Introduction: It has previously been reported that EMG variables recorded from the lumbar spinal muscles may be recorded reproducibly, are able to discriminate low back pain subjects from normal volunteers and are predictive of future back pain. At present, however, an experienced operator is required to acquire the signals and to determine the value of some variables. This has hindered the transfer of the technique from the laboratory to the clinical setting.

Methods: The EMG signal is subjected to a Fast Fourier Transform and a power spectrum is produced. An Expert System has been developed to examine this power spectrum. In accordance to a rule base several variables are generated including the half width. The error analysis can detect a number of possible errors of recording that can affect test results and unusual traces are flagged for further consideration. In some defined cases a correction is automatically applied.

Results: The Standard error between tshe manually generated half width and the automatically calculated value is 30%. Using the automated system 5% of subjects were found to change classification from normal to at risk. The sensitivity and specificity of detecting recording errors was 0.5 and 0.4 respectively. Work is ongoing.

Conclusions: The new system has reduced data set analysis from days to minutes, thus many different methods of analysis can be compared and contrasted readily. The automatic calculation of half width and other variables has brought clinical usage one step closer, and allow EMG analysis to provide a useful tool for monitoring treatment and measuring outcome.

Statement of Purpose: To enable GP’s and nurse practitioners to refer quickly, appropriately and effectively, at the first diagnosis of lower back pain.

Methods and result: Patients at the clinic, who were assessed and diagnosed by a GP/Nurse Practitioner, were asked to fill in an electronic questionnaire. The results of these were passed into a database where they could be accessed by an expert system program. This system used rule based logic and data mining concepts to assess the questionnaire answers, and presented a diagnosis of the patient. To determine system accuracy diagnoses were compared with actual diagnoses from the GP/Nurse Practitioner.

Conclusion: This project has been beset by several problems. The first being that a lack of patients with certain diagnoses has meant that it has been impossible to test the system with the more rare back problems.

The system accuracy is too low for the system to currently be of any use. This project is ongoing, the accuracy has improved significantly over the past year and we expect the improvement to continue next year. However, we have identified some problems in improving the accuracy. It has been noticed that there is a certain apathy present in some patients completing the questionnaires, resulting in less than accurate answers. Also the system can only produce one diagnosis. Patients with two back problems will get an incorrect diagnosis from the system.