Hi Erika! Thanks for this question! When I made this slide, I was thinking of monofilament testing when I mentioned protective sensation. I did a quick search of the literature today and found that most sources are using monofilament testing as the primary means of screening protective sensation (although, as mentioned in the lecture, screening other modalities is also important).
I found a couple articles indicating that vibration may be a beneficial addition to the protective sensation screen: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6966840/pdf/13047_2020_Article_371.pdf and https://onlinelibrary.wiley.com/doi/pdf/10.1111/dme.13989.
For NCS purposes, I think understanding the components of a comprehensive sensation screen, including using a Semmes-Weinstein 5.07 monofilament, is sufficient.
Hope this helps!
Chrissy