Development and verification of technologies for novel gait training paradigms

Walking is a fundamental activity for healthy ageing. However, in older age ambulatory abilities can be threatened by lower-limb disabilities as well as by the concurrent, natural physical decline. Considering that we are living in an ageing world, our society is called to find sustainable solutions for preserving gait functional abilities throughout ageing and disability. In this framework, newly emerging wearable technologies represent potential allies to pursue healthy ageing and to ensure a decent quality of life to people facing disabilities. This work explored the application of wearable devices for enabling novel paradigms of gait training, trying to answer the demand for evidence of the beneficial effects of such devices with end-users. In particular, a powered hip exoskeleton has been exploited for assisting gait in individuals with reduced mobility. The exoskeleton was found to reduce the energetic cost of walking in two transfemoral amputees during pilot, treadmill-based tests. The same device – when adopted for gait training with elderly subjects – lead to improved cardiopulmonary functions by means of an exercise regimen requiring less effort than without the exoskeleton. In comparison, a control group performing an equivalent volume of natural walking did not yield significant changes in their aerobic fitness. The beneficial rehabilitative effects of training with the orthosis, concurrent to the lower effort needed for exercising, proved for the first time the feasibility of using exoskeletons for training aerobic fitness in frail individuals. In another study, the effectiveness of a wearable system for vibrotactile feedback was investigated for improving symmetry of transfemoral amputees during overground walking. The device in question was a novel portable system conceived to provide non-invasive, bilateral stimulations at the level of the waist by means of vibrating motors and timely with gait events detected with a pair of shoes with pressure-sensitive insoles. The development and verification of the insole sensing technology as well as the assessment of waist haptic perception with the sensory feedback device were preliminary studies also object of this work. As for the experimental protocol with amputee end-users, concurrent vibrotactile feedback was shown to increase the temporal symmetry of the participants. Future experiments are still needed to investigate motor learning determinants and to identify the optimal training modalities for this kind of devices. Overall, this work contributed to advance the state of the art on lower-limb exoskeletons and non-invasive sensory feedback devices with proof-of-concept studies with end-users, towards their adoption for daily gait training. The performed studies identified potential new advantages of exoskeletons as enabling technologies for active ageing and provided insights on the utilization of augmented feedback to correct detrimental gait deviations.