ROLE OF ELECTROMYOGRAPHY IN THE ASSESSMENT OF LUMBAR PATHOLOGIES

Lumbar pathologies can include a wide range of medical conditions such as simple myalgia or severe neurological disorders. One way to assess the behaviour of paravertebral muscles consists in using electromyography (EMG), which converts the bioelectric potential of muscle activity into numbers. These data allow us to configure an electromyographic semiology for various pathologies. The purpose of the paper is to analyse the activity of paravertebral muscles through electromyography. The results will be used to develop a rehabilitation programme aimed at reducing muscle imbalance. The study involved 10 middle-aged patients suffering from low back pain and having an average body mass index of 23.44 kg/m2. Clinical assessment was based on the Waddell Disability Index (WDI) and the Low-Back Outcome Scale (LBOS). Muscle activity was assessed using surface EMG. Data were collected at two distinct times: while standing and during walking. Of the obtained parameters, we tracked action potential amplitude. The results allowed the classification of patients into three groups: patients with acute, subacute and chronic low back pain. Average values of the three subcategories showed important fluctuations as follows: while standing, they were 37.72 μV (acute form), 19.18 μV (subacute form) and 7.05 μV (chronic form), and during walking, they were 43.26 μV (acute form), 30.87 μV (subacute form) and 21.10 μV (chronic form). Statistical analysis was performed and significant inverse or direct correlations were observed between LBOS (-0.884) or WDI (-0.944) scales and dynamic EMG values. Thus, obvious relationships were established between surface EMG parameters and assessment scale values.