Lace migration describes a gradual movement of shoe laces toward the forward bend (flexor surface) of a shoe which can cause a tightening and restricting pressure at the top of the shoe (or binding) . Reduced volume available to the foot may lead to fatigue, pain, numbness and restriction of natural foot swelling. It also loosens the fit around the footwear’s metatarsal (ball) area, which can cause increased slipping and reduction of forward foot stabilization. Resultant friction between surfaces frequently is the cause of painful blisters. Manufacturers of exercise shoes traditionally reply on a lacing medium i.e. laces, to secure a comfortable fit. This has been hampered somewhat but new lacing design and technology have provided better options.
New Balance® Sure-Lace Shoelaces have a bubble shaped design which locks laces in place through the eyelets and makes the knot highly slip-resistant.
Now Xtenex laces take the bubble concept further and because the yarn is elasticated it allows customized tension/tightness of the lace along the entire length of the shoe.
According to the manufacturer this also enables the shoe to expand elastically under load while maintaining a secure fit to the foot.