Objectives: The current study aimed to compare between the chronic non-specific low back pain (CNSLBP) and healthy subjects during four phases of the trunk flexion-extension task (standing, flexion, relaxation, and extension phases) by using pool coherence as well as pairwise coherence of Beta band Intermuscular coherence (Bb-IMC) and flexion relaxation phenomena. Methods: Twenty-four men with CNSLBP and 20 healthy men voluntarily participated in this study. All subjects performed three tests of Flexion-extension task (F-ET) while the surface electromyography (sEMGs) were recorded from the right erector spinal muscle of the lumbar region "1", left erector spinal muscle of the lumbar region "2", right gluteus maximus muscle"3", left gluteus maximus muscle"4", right hamstring muscle"5" and left hamstring muscle"6". Accordingly, group A contains muscles 1, 4, and 6 and group B consists of muscles 2, 3, and 5. The pool coherence (PC) and the pairwise coherence (PWC) for all the above-mentioned muscles were calculated using Beta-band intermuscular coherence analysis. Thereafter, the mean pool coherence (mPC) was considered for group A and group B for four phases of F-ET in three groups as following: CNSLBP patients group, healthy subjects group and the third group included all subjects that participated in this study, whether patients or healthy and it was called the general group. Moreover, the mean pairwise coherence (mPWC) among each pair of group A and B muscles was calculated for four phases of F-ET using Bb-IMC in CNSLBP patients and healthy subjects. Results: These results indicated a high value of A mPC in the general group and healthy subjects in the fl exion phase, whereas the same A mPC in CNSLBP patients was high in all phases of F-ET. On the other hand, while B mPC was high in the general group and healthy subjects in the extension phase; it was high in all phases of F-ET in CNSLBP patients; B mPC in CNSLBP patients was high in extension, standing, and fl exion phases. A mPWC and B mPWC were not signifi cantly different between CNSLBP patients and healthy subjects in all phases of F-ET. However, only A mPWC "1-4" and the A mPWC "4-6" were signifi cantly smaller in CNSLBP patients compared to the healthy subjects in the relaxation and fl exion phases, respectively. Hence, we suggest pool coherence of Bb-IMC, not pairwise coherence of Bb-IMC, to compare CNSLBP patients and healthy subjects. Conclusions: According to the present fi ndings, we suggest using the pool coherence of Bb-IMC in the clinical examination for CNSLBP patients and studying the probable cortical effects and the effectiveness of various treatments on corticospinal tract function in CNSLBP.

Background: Until now, a variety of techniques have been introduced to address the adverse effects of NS-CLBP, including spinal manipulation technique (SMT) and muscle energy technique (MET). However, most of these techniques have focused on pain assessment and disability. In other words, the intermuscular synchronization between the co-contracting muscles was not considered, and hence, the effectiveness of these techniques on the corticospinal tract function was not studied. Objectives: This study aimed to compare the effects of SMT and MET on corticospinal tract function during four phases of standing, flexion, relaxation, and extension in flexion-extension task (F-ET) in NS-CLBP using pair-wise coherence of Beta-band intermuscular coherence (Bb-IMC). Methods: Twenty volunteer healthy male subjects and twenty-four male subjects with NS-CLBP (20-45 years of age) participated in this work. The patients had continuous or recurrent symptoms for three months or more without any referral pain to the lower extremities. The patients were randomly assigned to two equal intervention groups (SMT and MET), and the techniques were applied as described by Greenman. Surface electromyography (sEMGs) from lumbopelvic muscles was recorded for all participants (i. e., healthy group and the patient groups), while they performed three trials of F-ET, and the pair-wise coherence for all muscles was calculated using Bb-IMC analysis. Besides, in the patient's groups, sEMGs from the muscles were recorded before and after the interventional techniques (i. e., SMT and MET), while they performed three trials of F-ET, and the pair-wise coherence was calculated. Multivariate analysis of variance test was used to compare the healthy subjects and patient groups before the interventions in A and B muscle cross at different phases of F-ET task. Furthermore, in the NS-CLBP patients, comparisons were made before and after the interventions in each group (i. e., SMT and MET groups) as well as between the two groups in A and B muscle cross at different phases of the F-ET task. Results: In the standing phase of F-ET, there were no significant differences in the SMT and MET group before and after the intervention in PWC of A muscle cross and B muscle cross (P < 0. 05). Considering the flexion phase, there were significant differences in the SMT group in all pair muscles as PWC (M1-M4), PWE (M1-M6), PWC (M4-M6) (P < 0. 05), whereas there was one significantly in PWC (M4-M6) in the MET group (P < 0. 05). In the relaxation phase, the SMT had significantly in PWC (M2-M5), whereas there was one significantly in PWC (M4-M6) in MET group (P < 0. 05). In the extension phase, although the SMT was not significant (P < 0. 05) in the MET intervention group, there were significant differences in the PWC (M2-M3) and PWC muscles (M2-M5). Conclusions: This study provided some pieces of evidence about the effects of one of the common manual therapy techniques on the primary motor cortex and corticospinal drive in the NS-CLBP patients. The results showed that, by increasing the pair-wise coherence in all phases of FE-T, SMT intervention was more effective than MET intervention. Therefore, the pair-wise coherence of Bb-IMC can be considered an approach for clinicians when designing the rehabilitation protocol to ensure optimal treatment.

Introduction: This study aimed to investigate the reliability and agreement of the Beta-band Intermuscular Coherence (Bb-IMC) as a clinical assessment tool for Non-Specific Chronic Low Back Pain (NS-CLBP) patients and healthy subjects by studying four phases of the Flexion-Extension Task (F-ET): standing, flexion, relaxation, and extension phases. Materials and Methods: Twenty-four men with NS-CLBP and 20 healthy subjects voluntarily participated in this study. All subjects performed three trials of F-ET while the surface electromyography was recorded from the lumbar erector spinal, gluteus maximus, and hamstring muscles of both sides. Beta-band intermuscular coherence analysis was used to calculate the pool coherence and the pairwise coherence for all mentioned muscles. Afterward, the Intra-class Correlation Coefficient (ICC), Standard Error of Measurement (SEM), and Minimal Detectable Change (MDC) for four phases of F-ET were used to analyze the intrarater reliability and agreement of the measurements. Results: The investigation of ICC, SEM, and MDC showed that the reliability was moderate to a high level for pool and pairwise coherence of Bb-IMC in all mentioned muscles for four phases of the flexion-extension task in NS-CLBP patients and healthy subjects. Yet, the agreement was low because the measurement error was relatively large. Conclusion: So far, no studies have used the Bb-IMC method to study low back pain, which is carried out in our research to check the reliability of this new method. Our findings revealed that pool and pairwise coherence obtained during F-ET have moderate to a high level of reliability for using Bb-IMC and could be considered a tool for the NS-CLBP patients’ assessment. Despite the small sample size investigated, in clinical practice the using Bb-IMC measure can help to study the interaction of corticospinal in NS-CLBP and also in healthy subjects. This measure requires larger sample sizes in addition to studying other circumstances and functional movements such as lifting weight. Further, more research appears to be warranted by the observed effectiveness of a particular intervention in modulation mechanisms of corticospinal tract function by Bb-IMC in NS-CLBP.

This study examined the EEG patterns changes of the brain’s hemispheres during convergent thinking (CT) and divergent thinking (DT).34 subjects (19 boys and 15 girls) were chosen according to the convenience sampling. Each of them assigned in three condition (rest, CT and DT). In all 3 conditions EEG patterns were recorded from 19 scalp electrodes. The recorded EEG in theta band, were transformed into quantitative form (QEEG) by using Neuroguide software and then were analyzed by repeated measures ANOVA method. The results showed differences in left and right hemispheres, separately, DT and CT had higher coherence than rest condition. Moreover, the results revealed that two hemispheres hadn’t significantly coherence differences during these conditions.