[nestorD]

If the authors of the article are reading this: I would also do a test to see if the variance of the two groups (bionic vs normal) is significantly different. I did not check it but bionic might be very beneficial to some and detrimental to others which would not be seen when looking at the mean (you should also plot the distributions, it pretty much always a good first reflex).

[hoodwink]

for sure. due to this improved experiment design, we should now have the data to perform paired analyses rather than just looking at means.

what test do you use to compare variances though?

[nestorD]

There are several options but the Levene test should be appropriate: https://www.itl.nist.gov/div898/handbook/eda/section3/eda35a...