Analysis of Asymmetry of the Forces Applied on the Lower Limb in Subjects with Nonspecific Chronic Low Back Pain

OBJECTIVE Several studies have investigated asymmetry and loading patterns in different spine pathologies, motor disorders, and other conditions; there is a lack of knowledge on these aspects in chronic low back pain (CLBP). The aim of this study was to analyse asymmetry and loading patterns in patients with nonspecific chronic low back pain (NCLBP) compared to normal individuals, during walking. METHOD Forty participants (20 healthy subjects and 20 patients with NCLBP) participated in the study. Asymmetry of the force was measured based on the Asymmetry Index (ASI). The difference in the mean values of all data between the two groups was examined using the independent t-test. RESULTS The mean value of the first peak of ground reaction force of normal subjects was 1.02 ± 0.0354 N/BW compared to 1.038 ± 0.099 N/BW in NCLBP patients (P = 0.25) and 0.1004 ± 0.036 N/BW mediolateral force applied on the leg in normal subjects compared to 0.089 ± 0.022 N/BW in NCLBP patients (P = 0.214). The Asymmetry Index (ASI) of the first peak of vertical force was 2.59% ± 1.89% and 3.88% ± 2.94% for NCLBP and normal subjects, respectively, P = 0.2. CONCLUSION Therefore, it can be concluded that NCLBP subjects follow avoidance-endurance model without any limitation during walking.