For a cross-sectional comparative study, the researchers wanted to determine if there was a link between lumbar muscle asymmetry and trunk lateral range of motion (ROM) asymmetry in patients with nonspecific chronic low back pain (NSCLBP). In patients with NSCLBP, an imbalance in trunk muscle activation between the right and left sides might cause pain by stressing the spine improperly. In a study, NSCLBP patients had more asymmetry in the FR phenomenon of the erector spinae than asymptomatic subjects (APs). Asymmetry in muscle qualities such as trunk ROM had been proposed as a possible source of the observed asymmetry. About 3 standing maximal trunk flexions were conducted by 28 NSCLBP patients and 22 AP patients. For the erector spinae longissimus and lumbar multifidus, surface electromyography was obtained bilaterally. For each muscle, an FR ratio was computed. To measure trunk lateral ROM, the fingertip-to-thigh test was used. The absolute difference between the right and left sides was used to calculate the asymmetry of each parameter. The trunk lateral ROM of NSCLBP patients was much lower than that of AP patients. The erector spinae FR ratio asymmetry was substantially higher in NSCLBP patients than in AP (P<0.05). The multifidus FR ratio asymmetry and trunk lateral ROM asymmetry did not differ substantially across groups. Only patients with NSCLBP showed a significant connection (r=0.49) between FR ratio asymmetry of the erector spine and trunk lateral ROM asymmetry. The current findings revealed that erector spinae longissimus FR ratio asymmetry was marginally linked with trunk lateral ROM asymmetry. Furthermore, the patients with NSCLBP had a reduced trunk lateral ROM, as well as an FR ratio asymmetry of the erector spinae that was linked to trunk rotation. The data pointed to an imbalance in spine loading, which might have played a role in pain persistence.
Link:journals.lww.com/spinejournal/Abstract/2020/01010/Flexion_Relaxation_Ratio_Asymmetry_and_Its.5.aspx
