A comparison of the anatomical and biomechanical parameters of the foot in Maori and non-Maori
Background: Māori have poorer health outcomes compared to non-Māori and are over-represented in amputation and age-standardised mortality rates in Aotearoa. There is limited knowledge on the biomechanical parameters of Māori feet with diabetes and peripheral neuropathy.
Aims: The primary aim was to evaluate differences in plantar fascia thickness, peak forefoot plantar pressures and pressure time integrals under the forefoot region between Māori and non-Māori with and without diabetes and peripheral neuropathy. A secondary aim was to determine the relationship between plantar fascia thickness and plantar forefoot pressures under the forefoot in Māori with diabetes.
Method: A cross-sectional observational study was conducted on 36 participants recruited from two clinical sites (South Auckland and North Shore, Auckland). Participants who met the inclusion criteria were divided into four groups: Māori with diabetes, Māori with no diabetes, non-Māori with diabetes and non-Māori with no diabetes. Plantar fascia thickness was measured by ultrasound. Forefoot peak plantar pressure and pressure time integrals were evaluated. Data of the four groups were analysed using a Kruskal Wallis test and a Pearson’s r-correlation to analyse the relationship between plantar fascia thickness and plantar pressure.
Results: No significant differences were found between age, gender, body mass index (BMI) or diabetes duration (for people with diabetes) across the four groups (p>0.05). Plantar fascia thickness showed significant differences between the groups (p=0.02). Post-hoc analysis demonstrated significant increases between Māori with diabetes and non-Māori with no diabetes (p=0.04); and non-Māori with diabetes and non-Māori with no diabetes (p=0.01). Peak plantar pressure demonstrated significant differences across the groups for the 2nd/3rd MPJ (p=0.01) and 4th/5th MPJ (p=0.02), but no difference for the 1st MPJ (p=0.10). No significant differences in pressure time integrals were found in the four groups across the forefoot region (p>0.05). In Māori with diabetes, a significant relationship was found between plantar fascia thickness and peak plantar pressure at the 4th/5th MPJ (r = 0.77; p =0.01).
Conclusion: The preliminary results found biomechanical changes to the plantar fascia and increased plantar pressures in the lateral forefoot of Māori with diabetes and peripheral neuropathy. Evaluating other biomechanical risk factors may be used in future studies to evaluate predictors that may contribute to diabetic foot complications in Māori with diabetes.