FRI0471-HPR Evaluation of muscle fatigue of lumbar multifidus and activation of transversus abdominis in subjects with lumbar disc herniation
Authors: L.V. Ramos, F.R. França, B. Callegari, T.N. Burke, R.R. Caffaro, A.P. Marques
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Chronic low back pain (cLBP) is defined as back pain lasting more than 12 weeks in the lumbar and sacral levels of the spine. The intervertebral disc herniation into the vertebral canal may cause the pain and affects the transversus abdominis (TrA) and Lumbar Multifidus (ML) muscles that are preferentially attacked front episodes of nonspecific low back pain, promoting structural and morphological changes and difficulty in motor control. However, there is scarce literature that has evaluated the fatigue of ML and activation of TrA in individuals with lumbar disc herniation. <h3>Objectives</h3> To assess the fatigue of lumbar multifidus muscle and the ability of activation of transversus abdominis muscle in individuals with lumbar disc herniation. <h3>Methods</h3> This study examined 51 subjects divided into two groups: Lumbar disc herniation (LDH) (n=28, Mean age 44.79 (6.73), BMI 26.36 (2.79) and Control (without pain) (CG) (n=23, Mean age 39.22 (8.39), BMI 24.12 (2.14). Pain was evaluated withVisual Analogue Scale (VAS),functional disability with Oswestry disability questionnaire,the abilityof activation of TrA with pressure biofeedback unit (PBU), and back muscle fatigue (Lumbar multifidus muscle examined by the median frequency-MF) comprised an isometric endurance time (Sørensen's test) with concomitant measures of electromyography. Intergroup statistical analysis was performed using the t test* and Mann- Whitney** for data with normal and without normal distribution respectively.A significance level was α=0.05. <h3>Results</h3> Lumbar multifidus muscle fatigue shows reduced spectrum of frequency (Hz) in both groups, however the LDH group presents more intense fatigue (MF Initial LDH - 155.8±3.07; CG - 179.6±21.13; <i>p</i>&lt;0.001*/MF End LDH - 142.6±26.21; CG - 164.4±25.16; <i>p</i> =0.004*) and this occurs in shortest time (s) (LDH - 157.5±72.5; CG - 240±0; <i>p</i>&lt;0.001**). The LDH group shows moderate pain (6.4±1.98) and minimal functional disability (17±3.02). In the activation of TrA, it shows lower values (LDH -1.19±1.24; CG -3.91±2.07;&lt;0.001**). <h3>Conclusions</h3> The study suggests that LDH group have greater fatigue of lumbar multifidus muscle, lower endurance time and worse activation of TrA capacity when compared to individuals of Control group. <h3>References</h3> Awad JN, Moskovich R. Lumbar disc herniation. Clin Orthop Relat Res 2006; 443: 183-97. Elfving B, Ne'meth G, Arvidsson I. EMG spectral parameters and subjective rating of back muscle fatigue in healthy men and women. Scand J Rehabil Med. (2000) 32:117–123. Dedering A, Ringdahl KH, Ne'meth G. Back extensor muscle fatigue in patients with lumbar disc herniation, pre-operative and post-operative analysis of electromyography, endurance time and subjective factors, Eur Spine J, 2006, 15: 559–569. Cairms MC, Harrison K, Wright C. Pressure biofeedback: a useful tool in the quantification of abdominal muscular dysfunction? Physiother, 2000, 86(3): 127-38. <h3>Disclosure of Interest</h3> None Declared