Three randomized shoe-lacing conditions, which differed in lacing tightness (comfortable, loosened, and completely loose) were investigated in 20 healthy adults. On a 10-m walking test, plantar pressures were assessed with the Pedar®-X in-shoe measurement system. Perceived in-shoe displacement was scored on a numerical rating scale.
With respect to the pressure time integral statistically significant effects were found in the hallux, toes 2–5, first metatarsal head, and lateral midfoot regions. Post hoc comparison showed for the hallux: mean increase of 45.5 kPa s (95 % confidence interval [CI]: 3.2–87.8 kPa s), and toes 2–5: mean increase of 23.5 kPa s (95 % CI: 0.1–46.9 kPa s) between comfortably secured and completely loosened laces; lateral midfoot: mean decrease of −18.1 kPa s (95 % CI: −31.5 to −4.8 kPa s) between comfortably secured and loosened laces. No significant effect was found on peak pressure, and average pressure. Participants reported a significant increase in heel slipping and in slipping back and forth of the foot as the laces were loosened.
Looser lacing techniques resulted in small peak and average plantar pressure changes (less than 3 % and 6.5 % respectively). Pressure time integral under the hallux and toes 2–5 increased 16.3 % and 14.5 % respectively, and perceived in-shoe displacement increased as compared to comfortably secured laces. These results suggest that diabetes patients should be advised to comfortably tighten their shoelaces during the whole day.