A Workaround for Recruitment Issues in Preliminary WR Studies: Audio Feedback and Instrumented Crutches to Train Test Subjects

One of the main problems in studies involving exoskeletons for assisting gait of Spinal Cord Injury (SCI) users is recruitment of a suitable number of subjects, especially when age, gender, and pathologies are considered. Studies involving able-bodied subjects could instead rely on a considerable number of subjects, but the reliability of the results when transferred to real exoskeleton users is limited. This limitation could be partially solved using able-bodied subjects for preliminary tests. In this paper, we describe a first approach to train able-bodied subjects to behave as SCI subjects during walking. An audio feedback driven by a pair of instrumented crutches has been used to train healthy subjects during exoskeleton walking. To test the system, 22 able-bodied subjects have been analyzed during a straight walk with and without the audio feedback. Results show that the audio feedback induces a learning effect and a persistency effect in the participants.