Effects Of Arch-supporting Functional Insoles On Plantar Pressure Distribution Duringrace Walking

PURPOSE: To investigate the effectiveness of functional insoles on plantar pressure distribution during race walking. METHODS: Twenty male race walkers (age: 21.19 ± 3.66 years; height:178.85 ± 14.07 cm; body mass:69.48 ± 5.43 kg) were recruited. Each participant wore his/her own walking shoes and walked 400 m with an average race-walking speed (3.5–3.8 m/s) under two conditions: (1) wearing arch-supporting functional insoles, and (2) wearing normal insoles. Plantar pressure insoles were placed in shoes to collect plantar pressure data. The peak pressures of ten anatomical sub-regions and GRF of the whole foot were recorded during the test. Ten anatomical sub-regions were identified as the medial heel (HM), lateral heel (HL), medial arch (VM), lateral arch (VL), metatarsal-phalangeal joint (MPJ) 1 to 5 (M1, M2, M3, M4, and M5) and the hallux (T1). A two-way repeated ANOVA was used to compare plantar pressures in 10 different parts of the foot and in two conditions. RESULTS: With functional insoles, the peak pressures significantly decreased in T1 (functional (f) = 373.2 ± 76.4 kPa, normal (n) = 433.1 ± 82.1 kPa, p = .012), M1 (f = 448.1 ± 88.5 kPa, n = 538.4 ± 107.5 kPa, p = .005), M2 (f = 334.2 ± 65.7 kPa, n = 445.5 ± 89.3 kPa, p < .001), M3 (f = 296.1 ± 59.0 kPa, n = 362.2 ± 71.7 kPa, p = .002), M4 (f = 241.4 ± 49.7 kPa, n = 299.7 ± 58.9 kPa, p = .031), HM (f = 348.4 ± 46.4 kPa, n = 549.4 ± 109.9 kPa, p < .001) and HL (f = 360.7 ± 69.4 kPa, n = 573.2 ± 113.8 kPa, p < .001), compared with those with normal insoles, but increased in VM (f = 167.2 ± 33.3 kPa, n = 46.0 ± 9.2 kPa, p < .001). With functional insoles, the first force peak decreased (f = 1.25 ± 0.1%Body weight, n = 1.32 ± 0.2%Body weight, p = .034). CONCLUSION: During race walking, the peak pressure in the MPJs and heels was reduced by arch-supporting functional insoles. The reduction in the first force peak suggests that the arch-supporting functional insoles absorb the vertical shock during the initial foot contact phase of the heels and thus prevent the potential injury risks.