Can humans perceive the metabolic benefit provided by augmentative exoskeletons?
Roberto Leo Medrano, Gray Cortright Thomas, Elliott J Rouse
PMID 35219335WHAT IT FOUND
On average, ten able-bodied walkers needed to feel a 22.7% change in walking energy use before noticing it.
State-of-the-art exoskeletons reduce walking energy use by approximately 14%, so the average wearer likely cannot consciously perceive the metabolic benefit.
Key findings
01The average perception threshold was a 22.7% change in metabolic rate, with 75% accuracy.
02State-of-the-art exoskeletons have consistently reduced walking metabolic expenditure by approximately 14% relative to not wearing an exoskeleton.
03No significant relationship was found between fitness variables and the estimated perception threshold.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study tested only ten able-bodied adults, not people with disabilities or clinical gait problems. The outcome was conscious perception of metabolic rate, not walking function, safety, fatigue, or patient-reported outcomes. The exoskeletons changed metabolic rate indirectly, and many uncontrollable factors could add noise to the estimates. The device torque limited the range of metabolic rates that could be tested, which added uncertainty for participants with high thresholds. The study used about 100 trials per participant, whereas conventional psychophysics would use about 300. This added uncertainty. Participants may have based their responses on feelings of torque, comfort, or timing rather than metabolic rate alone. Short treadmill trials may not reflect longer real-world use. The analysis found no significant relationship between fitness variables and perception thresholds, but the study was not powered for that question.
The easy way to misread this
Do not conclude that exoskeletons have no benefit. The study measured short-term conscious perception of metabolic rate in ten able-bodied participants, not patient function, and three participants had thresholds below the typical 9.6% reduction.