Paradoxıcal effect of body mass index ranges on pedobarographic evaluatıon

Although there is evidence suggesting that obesity alters plantar pressure distribution, the specific effects of certain body mass index (BMI) ranges on pedobarographic measures in healty individuals has been poorly investigated. A cross-sectional study with 167 healthy participants was conducted to assess plantar pressure changes across 4 BMI ranges: Under/normal weight (NW), overweight (OW), obese (OB), severe obese (SO). Subjects walked on the Footscan® pressure plate at a self-selected speed, and peak plantar pressure (PPP), load rate, and contact area values were recorded. The foot was divided into 10 zones: hallux (T1), toes 2-5 (T2-5), metatarsals 1-5 (M1-M5), midfoot (MF), medial hindfoot (MH) and lateral hindfoot (LH). PPP underneath M2-M4 was lowest in the NW group (p = 0.011), and although PPP values for the SO group were lower than those for the OW and OB groups, these differences were not statistically significant. Load rate values of M2-M3 were lower in both the NW and SO groups (p = 0.008) compared to the OW and OB groups. In addition, the metatarsal load rate values for the SO group were generally lower than those for the NW group. The total metatarsal contact area of both the NW and SO groups was lower (p = 0.019) than that of the OW and OB groups in both feet. These findings suggest that as BMI increases, PPP, load rate, and contact area in the middle metatarsal region initially increase, stabilize early in obesity, and then decrease at advanced stages, indicating a shift of the load to the midfoot.