Objective To explore the characteristics of the plantar pressure data of the patients with adolescent idiopathic scoliosis(AIS), and evaluate the correlation between plantar pressure parameters and coronal balance status for AIS.
Methods A total of 44 patients of AIS were recruited as volunteers. Radiographic studies including Cobb angle, offset between central sacral vertical line(CSVL) and C7 vertebra plumb line(C7 PL)(considered as global coronal balance, GCB), apical translation of the major curve(AT, considered as regional coronal balance) and lateral pelvic tilt(LPT) were measured. The static plantar pressure test was carried out on the subjects, and the biomechanical indexes such as the contact area and the load ratio(relative to the overall load of the feet) of the feet were tested to analyze the plantar pressure distribution characteristics of AIS patients.
Results The contact area of the forefoot was significantly larger than that of the rearfoot(
P<0.001) and the load ratio of the forefoot was significantly smaller than that of the rearfoot(
P<0.001). The offset between CSVL and C7 PL was positively related to the contact area of the forefoot(
r=0.357,
P=0.019), as well as the load ratio(
r=0.400,
P=0.008). The AT was also positively related to the load ratio of the forefoot(
r=0.331,
P=0.030) but had no correlation with contact area.
Conclusion In scoliosis, the coronal balance is correlated to plantar pressure distribution. The offset between CSVL and C7 PL, as well as AT are the best describers of coronal balance. These two indexes can best reflect the equilibrium state of coronary position. On the main bend side, the offset between CSVL and C7 PL is positively correlated with the contact area and the load ratio of the forefoot, and the TA is also positively correlated with the load ratio of the forefoot, which indicated that the balance characteristics of the two coronal positions are all correlated with the foot pressure.