Objective: This study examined the impact of shoe closure on plantar thermal stress response (TSR), which is known to be a surrogate of shear stress and skin perfusion. It is aimed to explore potential impact of shoe closure on increasing risk factors associated with plantar ulcers in people with diabetic peripheral neuropathy (DPN).
Methods: Fifteen eligible subjects were enrolled. The left foot was used as a reference and fitted to a self-adjusted and habitual lace-tightening method by each subject. The right foot was used as a test closure and fitted into three lace closure conditions: loose, tight, and preset optimal closure (reel clutch, BOA technology). Thermal images were taken after 5 minutes of acclimatization (pre-trial) and immediately after 200 walking steps in each shoe closure condition (post-trial). TSR was calculated from the thermal images.
Results: TSR was significantly higher in the test closure with loose (70.24%, P = .000) and tight (66.85%, P = .007) and lower (-206.53%, P = .000) in the preset optimal closure when compared to the reference closure. Only lace closure conditions affected TSR with no significant impact from age, BMI, and gender in our sample in a multivariable regression model.
Conclusion: The results from this study suggest that shoelace closure technique can have a profound effect on TSR. It therefore stands to reason that optimal lace closure may have an impact in reducing risk of plantar ulcers in people with DPN. Interestingly, results revealed that even a self-adjusted lace closure may not be necessarily optimal and a preset closure setting like reel clutch might ultimately be recommended to minimize risk. Further study is warranted to confirm or refute these interesting results.
Keywords: diabetic foot ulcer; shear stress; shoe closure; shoelace; thermal response to stress.