[The distribution and biomechanical characteristics of foot deformities among elderly diabetic patients based on community screening].

To analyze the distribution characteristics of foot deformities and the biomechanical features of the feet among elderly diabetic patients in the community. A total of 3 148 elderly diabetic patients (6 296 feet) who participated in the diabetic foot screening program in Jinshan District, Shanghai, from March to May 2023 were included, with 1 357 males and 1 791 females, aged (70.7±6.0) years. According to arch deformities, the severity of hallux valgus, and the presence or absence of other toe deformities (hammer foot, mallet foot, and claw foot), the patients were grouped and compared in terms of biomechanical parameters such as plantar pressure, force-bearing area, foot axis angle, footprint length, and load ratio. The the most common foot deformity was the combination of arch deformities, accounting for up to 41.0% (2 581/6 296), it was followed by hallux valgus at 21.8% (1 371/6 296) and other toe deformities at 13.4% (846/6 296). A total of 56.5% (3, 557/6 296) of the patients had at least one type of foot deformity, and 29.0% (1 032/3 557) presented with tow or more types of foot deformities. When grouped according to arch deformities, the patients in the low arch group, mild low arch group, normal arch group, mild high arch group, and high arch group was 343, 1 282, 3 715, 595, and 361 cases, respectively; and there were statistically significant differences in maximum pressure, mean pressure, force-bearing area, foot axis angle, anterior-posterior and lateral offsets of the center of plantar pressure, anterior-posterior foot load ratio, and medial-lateral load ratio among all the groups (all <0.001). The high arch group exhibited the highest maximum and mean pressures on the plantar surface, with the smallest force-bearing area, while the opposite was true for the low arch group (all P<0.001). There were 4 925, 731, 640 cases in the no hallux valgus group, mild hallux valgus group, and moderate-to-severe hallux valgus group respectively when grouped according to the severity of hallux valgus. The moderate-to-severe hallux valgus group had the lowest medial load (=0.002) and the highest lateral load ratio (=0.001). Compared to the group without other toe deformities (=5 450), the group with other toe deformities (=846) exhibited higher maximum plantar pressure [(214.43±112.85) vs (202.88±113.63) kPa, <0.001], a lower forefoot load ratio (54.35%±13.31% vs 55.94%±12.58%, =0.001), and a higher hindfoot load ratio (45.65%±13.31% vs 44.06%±12.58%, =0.001). Among elderly diabetic patients, the incidence rate of foot deformities is as high as 56.5%, with arch deformities being the most common. Foot mechanics analysis indicates that the high arch group has the highest maximum and average plantar pressures, but the smallest force-bearing area, while the opposite is true for the low arch group. Toe deformities can affect the patient's plantar load ratio.