Gait analysis of pregnant patients with lumbopelvic pain using inertial sensor

Background: Lumbopelvic pain (LPP) is one of the most common discomforts during pregnancy. However, few studies have evaluated relation between LPP and gait in pregnancy quantitatively. Research question: This study aimed to investigate the relation between the LPP and gait characteristics such as symmetry, stability, and the degree of motion during pregnancy. Methods: Gait data were collected for fifty-two pregnant women between the third and tenth month of pregnancy on smooth, horizontal walkway by using inertial measurement sensor units attached to the participants’ lumbar. The degrees of trunk movement, movement symmetry, gait variability, and symmetry of rotation were expressed as the root mean square (RMS), autocorrelation peak (AC), coefficient of variance (CV), and the degree of asymmetry at the approximate amount of angular variation (DA) respectively, which were calculated from measured acceleration data and angular velocity data. An independent t-test was performed to investigate differences in these gait parameters between LPP group and pain free group classified according to the presence or absence of the pain, which is evaluated by using a questionnaire. In addition, LPP group was divided into 5 subgroups based on the types of pain, and the differences between the groups were also investigated by using a one way ANOVA. Results: Rotational asymmetry was observed in movement of the roll direction of the LPP patients. The DA of the roll angle of the LPP group was significantly greater than that in the pain free group (0.140 ± 0.093 vs. 0.077 ± 0.053, respectively; p = 0.004). In the analysis of pain complications, the significant difference in DA of roll angle, and CV of yaw angle were observed. Significance: The results indicated that motion asymmetry of both rotation and translation increased significantly in LPP patients’ gait.