Electromyography Activity of the Abdominal Muscles Relative to the Active Pelvic Floor Muscle Contraction in Low Back Pain and Healthy Individuals

 The purpose of present study was to compare electromyography activity of the abdominal muscles in response to the active pelvic floor muscle contraction in individuals with and without low back pain (LBP). 

 A total of 30 female subjects (LBP=15) and (healthy=15) participated in the study. All subjects performed the active PFM contraction for three times. The correct pelvic floor muscle contraction was controlled by an ultrasound. Simultaneously, the electromyography signals of the right transverse abdominis, internal oblique and external oblique muscles were measured. Variables of electromyography amplitude were analyzed using an independent sample T-Test. 

 There was a high intra-tester reliability for electromyography measurement of abdominal muscle in LBP (ICC>90) and healthy individuals (77<ICC<96). Transverse abdominis, internal oblique and external oblique muscle electromyography activity were increased during the pelvic floor muscle contractions in both women group with and without low back pain. The results of independent sample T-Test displayed no statistically significant difference in muscle co-activation pattern of the abdominal and pelvic floor muscles between the healthy group and LBP group (P>0.05). The mean values for muscle electromyography amplitude in transverse abdominis, internal oblique and external oblique muscle were 0.37(0.41), 0.18(0.14) and 0.16 (0.10), respectively, for healthy individuals and 0.25 (0.17), 0.13 (0.19) and 0.18 (0.17) for individuals with LBP. 

 There is a recognizable co-activation between abdominal and pelvic floor muscles in healthy and low back pain women.