Filing in one direction?

Question:

Does filing in only one direction, towards the center, really help the nail?

Answer:

I have not found this to be true. I have tested this concept by using high magnification photography to record the results of various filing techniques. After examining nail plates filed using various abrasive grits and filing techniques. I didn’t observe any differences in the condition of the natural nail plate when comparing filing in only one direction with doing it in a back-and-forth fashion.

This study was conducted on normal, healthy nail plates, so perhaps there may be a difference if the nail plates are damaged, but this appears to be a myth. I’ve seen nothing to support the claim that filing in only one direction provides any benefits.