Social and health impacts of exoskeleton use on care workers.

Only eight care workers in one care home took part, seven in the measurements, and there was no control group: each nurse was compared with themselves on a different shift, so the study cannot say what would have happened without the suit over the same period. Some work tasks were measured in very few people, down to one nurse for bathing, so none of the task-level figures can support a conclusion. The nurses were volunteers and knew they were being studied. Several said this made them more careful about ergonomics, which may have hidden any benefit of the suit. The trial lasted three weeks, which nurses themselves said was too short and which for some working shifts meant only a few opportunities to use the suit. Only one passive exoskeleton model was tested, so the results say nothing about powered exoskeletons or other devices. Nurses filled in the diaries as they chose, so the record of how often and for which tasks the suit was actually used is incomplete. The authors state the measurements were there to support the interviews rather than to be a test with enough people to detect a difference on their own.

The study was paid for by the Finnish Work Environment Fund (grant 210359), a public funder, as part of the TUEKS project 'Exoskeletons and Caregivers' Changing Daily Work'. The authors declared no potential conflicts of interest. No role for the exoskeleton manufacturer is reported.

Do not read the lower muscle activity with the suit as proof that it reduces strain at work. Averaged over the workday the figures were 9.3% versus 8.6% of each nurse's maximum, and none of the differences, in any muscle or any task, reached statistical significance; the 7% average reduction mentioned in the discussion is the authors' description of that same non-significant trend. The one significant result went the other way, with discomfort rising during the shift when the suit was worn, though that rise was measured within the suit condition and the two shifts were not directly different from each other.