Lower Limb Exoskeleton During Gait and Posture: Objective and Subjective Assessment Procedures With Minimal Instrumentation

In this work, we propose and implement an enhanced methodology for assessing the impact of wearing a lower limb passive exoskeleton on the gait and posture of the wearer, integrating both objective and subjective assessment techniques. Using only an inertial measurement unit (IMU) and a heart rate monitor, we examined the gait of eighteen healthy volunteers during treadmill and overground walking, both with and without the exoskeleton. Postural control tests were conducted on a force platform and with an IMU during standing and crouching. Our findings indicate that exoskeleton use resulted in higher physical effort, perceived effort, and user frustration. Moreover, wearing the exoskeleton showed an augmented periodic stability, which is related to more constant strides, gait movements showed reduced smoothness, which is related to difficulties to adapt the strides in response to gait perturbations. Nevertheless, the exoskeleton exhibited better stability during stance, notably reducing medio-lateral displacement by over 30%. Finally, we found an increase in cognitive effort linked to exoskeleton use. These outcomes offer valuable insights into the comprehensive influence of exoskeletons on gait performance and user experience.