PURPOSE To analyze pelvic compensation during walking in patients with severe sagittal plane deformity by using motion analysis. METHODS A total of 44 patients with sagittal plane deformity who were scheduled to undergo surgery were included. Motion analysis was performed 3 consecutive times during walking to estimate the anterior pelvic tilt (Ant-PT) angle, trunk kyphosis (TK) angle, and distance of the center of gravity (CoG) from the center of mass (CoM) of the pelvic segment, and hip and knee joint angles during gait. The patients were classified into Ant-PT+/Ant-PT-, TK+/TK-, and CoG+/CoG- groups according to the changes in Ant-PT angle, TK angle, and distance of the CoG from the CoM of the pelvic segment. Increases and decreases in the values of the variables from the first trial to the third trial were indicated with "+" and "-" signs, respectively. RESULTS The mean Ant-PT angle, TK angle, and distance of the CoG from the CoM of the pelvic segment increased progressively, and the differences in the values of these variables from the first to the third trials were statistically significant (P = 0.046, P = 0.004, and P = 0.007 for the Ant-PT angle, TK angle, and distance of the CoG from the CoM of pelvic segment, respectively). Among the 44 patients, 27 and 34 were classified into the Ant-PT+ and CoG+ groups, respectively. Older age and higher body mass index (BMI) were significantly associated with the Ant-PT+ group. The CoG+ group demonstrated a significantly higher height and weight than the CoG- group. CONCLUSIONS Higher BMI, height, and weight are risk factors for progressive worsening of dynamic sagittal imbalance. These slides can be retrieved under Electronic Supplementary Material.

中文翻译：

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使用运动分析来分析动态矢状不平衡的骨盆补偿。

目的通过运动分析来分析严重矢状面畸形患者行走时的骨盆补偿。方法纳入计划接受手术的44例矢状面畸形患者。步行过程中连续进行了3次运动分析，以评估骨盆前倾（Ant-PT）角，躯干后凸（TK）角以及重心（CoG）与骨盆质心（CoM）的距离步态和臀部和膝盖关节步态角度。根据Ant-PT角，TK角以及CoG与骨盆段CoM距离的变化，将患者分为Ant-PT + / Ant-PT-，TK + / TK-和CoG + / CoG-组。 。从第一次试验到第三次试验的变量值的增减用“ +”表示 和“-”号。结果平均Ant-PT角，TK角和CoG距骨盆段CoM的距离逐渐增加，并且这些变量的值在第一次到第三次试验之间具有统计学意义（P = 0.046， P = 0.004，而Ant-PT角，TK角和CoG与骨盆段CoM的距离分别为P = 0.007）。在这44名患者中，分别将27名和34名分为Ant-PT +和CoG +组。老年人和更高的体重指数（BMI）与Ant-PT +组显着相关。CoG +组的身高和体重明显高于CoG-组。结论较高的BMI，身高和体重是动态矢状不平衡逐渐恶化的危险因素。