'On the impact of the identification of inertial sensors location on the estimation of segment and body centers of mass in transfemoral amputees: a sensitivity study' - Dataset

Gait analysis of people with transfemoral amputation is essential to support the rehabilitation process. In particular, the kinematics of the body center of mass (bCoM), derived from the motion of segments’ centers of mass (sCoM), provide crucial information about patients’ locomotion. Magneto-Inertial Measurement Units (MIMUs) may be adopted to obtain this information in-the-field. However, MIMUs provide the 3D acceleration of the origin of the sensor’s frame. Therefore, the relative position of MIMUs with respect to the corresponding sCoM must be retrieved to accurately estimate the sCoM and bCoM accelerations. Through an experimental design procedure, this paper investigates the sensitivity of the accuracy of  the sCoM and bCoM 3D acceleration estimated from five MIMUs positioned on the trunk, both thighs and both shanks to erroneous identifications of MIMUs positions in a transfemoral amputee.  Data from six gait cycles were used to simulate respectively 33 and 215 combinations of erroneous identification of MIMUs positions (± 2 cm) for the sCoM and bCoM sensitivity analyses. The correct identification of the positions of the trunk MIMU along the vertical direction and of the sound limb MIMUs along the vertical and anteroposterior directions was found critical for an accurate estimation of bCoM 3D acceleration components. These positions were shown to contribute to 81% (ML), 80% (AP) and 66% (V) to the total sensitivity and reduced the estimation accuracy of bCoM acceleration by 4.6% (ML), 3.9% (AP) and 2.6% (V). The accurate localization of these MIMUs is therefore paramount to provide relevant information for the  rehabilitation.