OBJECTIVE: This study aimed to investigate the characteristics of various plantar pressure parameters of patients with different curve locations (thoracic/lumbar) and types (single/double) of adolescent idiopathic scoliosis (AIS). METHODS: Seventy-eight moderate AIS patients were included from Nanjing Drum Tower hospital, who were then classified into 4 groups by curve location and type, single thoracic scoliosis (S-T, n = 20), single lumbar scoliosis (S-L, n = 16), double curves with major curve at thoracic region (D-T, n = 22), double curves with major curve at lumbar region (D-L, n = 20). Another 22 healthy subjects were included as the control group. Multiple static and dynamic features, such as medial-lateral (M-L) area ratio and loading pattern were compared across groups. RESULTS: For static plantar pressure, on the major curve side, the medial-lateral (M-L) area ratio was significantly different among five groups on both feet (P <
0.01). The ratio of S-T group was significantly lower than lumbar scoliosis groups on major curve side (P <
0.01). In midfoot, ratios of thoracic scoliosis groups were significantly lower than S-L group P <
0.01). On the compensatory side, D-L group had markedly lower ratio than thoracic groups in M-L area ratio and midfoot M-L area ratio (P <
0.01). For dynamic plantar pressure, the maximum pressure of medial rearfoot of thoracic scoliosis was significantly lower than lumbar scoliosis and control group on major curve side(P <
0.01). Meanwhile, the lateral rearfoot of thoracic had greater pressure than lumbar scoliosis groups (P <
0.01). The load distribution of metatarsal head (MH) had marked differences among groups on the compensated side, especially at MH1, MH4 and MH5 P <
0.01). Moreover, the loads of thoracic scoliosis were significantly larger than lumbar scoliosis at MH5 (P <
0.01). CONCLUSION: In moderate AIS patients, scoliosis curve location significantly affected static and dynamic plantar pressure while single or double curves had limited impact.