Validity of Pendant-Based IMU Assessment of Postural Stability Under Varying Balance Conditions Compared to a Sensor Positioned on the Lower Back

Body-worn inertial measurement units (IMUs) have been widely used in postural stability and balance studies because of their low cost and high level of convenience. In most studies, single IMU sensors are put on the lower back attached to a belt, placing the sensor near the body’s center of mass (COM). For some populations, such as pregnant women, wearing the sensor on a belt over the lower back presents challenges in terms of fit and comfort. Thus, it may be necessary to identify a better location for the sensor and a more comfortable means for attaching the sensor to the body. This study aims to implement and test a novel pendant IMU sensor hanging from the subject’s neck and placed over the sternum. Three standing tasks (double-leg, tandem, and single-leg standing) were performed under open-and closed-eye conditions for preliminary assessments of the ability of the new sensor to discriminate between balance conditions. Standard deviations were analyzed in different conditions, along with ROC curves and ANOVA analysis. The results showed that the pendant sensor can detect the signals as good as the sensor on the waist.