Analysis of the trunk motion for pregnant women with lumbopelvic pain using inertial measurement unit

Abstract

Many women undergo lumbopelvic pain (LPP) during pregnancy. The main factors for LPP are the physical stress related with change of posture and muscle relaxing around pelvis. Also it is thought that movement patterns during daily activity are associated with LPP. Therefore, this paper attempts to investigate the characteristic of movement patterns that have affect LPP during pregnancy. For this purpose, an experiment was conducted to measure standing up and sitting down of pregnant women using inertial sensor unit (IMU), which is simple device and is able to measure motions such as vibration or rotation quantitatively. Then movement evaluation parameters were calculated from measured data of lumber angular velocity. As the movement evaluation parameters, Maximum peak, Minimum peak, Peak to peak (PP: Range between Maximum peak and Minimum peak), Time of PP, PP divided by Time of PP, Root mean square of each parameter, and each parameter divided by BMI were calculated during both of stand up and sit down for each of roll, pitch, and yaw angles. Finally, we consider whether there is any relevance between LPP and movement characteristics by comparing the movement evaluation parameters of LPP group with these of non-LPP group. As a result, it appears that Maximum peak, PP/Time of PP, Maximum peak/BMI, PP/BMI, (PP/Time of PP)/BMI of pitch angle have some relevance to LPP.