Effects of orthotic devices and sensor feedback on the trunk and pelvis kinematics during gait of transfemoral amputees.

Background: Continuous training with expert monitoring is challenging and often restricted to hospitals or rehabilitation facilities.

Objective: To design a feedback system using orthotic devices and inertial sensors to align the pelvis and trunk in transfemoral amputee gait and to investigate its kinematic effects.

Study design: Within-subjects design.

Methods: Ten transfemoral amputees participated in this study. We developed a device that integrated an orthotic device and inertial sensor fixed to the trunk and pelvis, providing feedback. The participants performed walking trials without attachments, with only sensors with audible warning of inclination, with only the orthotic device, and with both the sensors and orthotic device.

Results: No significant differences in the similarity index parameters were observed under the 4 conditions; however, significant effects emerged in the trunk rotation and lateral bending ranges of motion (ROM; P < 0.05). Similar effects were observed in the anterior-posterior pelvic tilt, pelvic rotation, and lateral bending ROMs. The rotation and lateral flexion ROMs during the prosthetic leg stance phase decreased with combined orthotic device and sensor feedback or with only the orthotic device. Similarly, the lateral flexion ROM during the healthy leg stance phase decreased with sensor feedback. The pelvic lateral flexion ROM decreased during the prosthetic leg stance phase with only the orthotic device or combined sensor use, and rotation decreased with sensor-only feedback.

Conclusions: Unlike in the ROM, no noticeable change in the similarity index of the trunk or pelvis was observed. This combined feedback system may partially reduce compensatory movements in the trunk and pelvis during transfemoral amputee gait.