- Reddit: LPT: How to lace your running shoes (June 7, 2015)
- Reddit: Black toes from ultimate? (May 20, 2015)
- Runner's World: How To Lace Shoes: Prevent Black Toe Nails (March 4, 2011)
They link to these photos:
The claim is that this lacing technique is effective at protecting the toenail on your big toe from being blackened (subungual hematoma).
Is this true?
The most authoritative source that I found was (Adams, Brian B. "Traumatic Injuries to the Nails and Toes." Sports Dermatology (2006): 262-281), which says:
Lacing techniques can prevent the foot from freely slamming into the toe box, especially on downhill courses when there is a great deal of force pushing the toenail into the end of the shoe.
However, he simply asserts that without reference to empirical evidence, so it seems to be just a restatement of the claim.
I also found a chapter/article (Werd, Matthew B. "Athletic Shoe Lacing in Sports Medicine." In Athletic Footwear and Orthoses in Sports Medicine, pp. 79-87. Springer New York, 2010.) that repeats this claim, and calls the technique the "Distal–Medial Eyelet Lacing Technique", but again, there are no references or any mention of empirical evidence. He says that the purpose is to "pull the upper material off of the big toe and decrease the pressure on the great toe and joint".