Continuous sweep versus discrete step protocols for studying effects of wearable robot assistance magnitude.

Only seven participants were tested, and all analyses were within-participant, so between-person variability was not addressed. The authors did not correct for multiple testing, so some differences may be chance findings. The authors describe the study as explorative and say it is not a recommendation for one protocol over another. Participants completed extensive training and warm-up, adding an hour and 15 min of walking, so time savings may be smaller. Metabolic measurements relied on assumptions about steady state; fitted time constants were larger than the assumed 42-s value, which may have affected results. No muscle activity was measured, so changes in muscle activation could explain metabolic differences. The results depend on this soft exosuit, its controller, and the chosen sweep durations, so they may not generalize to other devices or populations.

Funding came from the Defense Sciences Office, DARPA; the National Science Foundation; Samsung; the Robert Bosch Stiftung; the Wyss Institute; the John A. Paulson School of Engineering and Applied Sciences at Harvard University; and the National Institutes of Health. The text does not state author disclosures or whether a sponsor designed or wrote the study.

Do not conclude that continuous sweeps are ready to replace discrete protocols for patient gait evaluation. This was an exploratory comparison in seven participants, metabolic cost did not match discrete steps in all directions, and the authors state it is not a recommendation.