Objective: To study the effects of simulating leg length inequality on the spine and pelvic posture in standing and walking states and to explore their compensatory laws. Methods: From January to April, a total of 44 healthy volunteers were rasterstereographically examined for spine and pelvis in Institute of Digitized Medicine, Wenzhou Medical University and Department of Orthopaedics, First Affiliated Hospital of Wenzhou Medical University.Volunteers wore uniform shoes, and single 5 mm thick insoles were customized.The simulating leg length inequalities (5-30 mm) were artificially created by increasing insole height.The parameters of 3D body surface parameters and 4D dynamic parameters of the pelvic and spine were measured and statistically analyzed in standing and walking states. Results: In the static standing state, with the increase of the difference of both lower extremities, coronal plane pelvic tilt and sagittal plane pelvic torsion also increased[the maximum value about (10.6±4.3) mm and (3.3±3.5)°], as well as the frontal deviation of the spine [the maximum value about (11.1±17.9) mm]. But the pelvic rotation, vertebral surface rotation angle (rms) and spine sagittal plane deviation were no obvious changes.In the walking state, with the difference between lower extremities increased, the maximum angles of vertebral surface rotation to the left and right and pelvic rotation to the left and right were no obvious changes, but (coronal) spinal maximum offset distance to left and right increased [the maximum value about (9.8±5.1), (10.4±6.9) mm]. Conclusion: The effect of the leg length discrepancy on the pelvic coronal plane and the sagittal plane changes are obvious, but little effect has on the pelvic cross section.The pelvis is compensated by the increase of the inclination of the coronal plane and the sagittal angle at first order.Similarly, the effect on the coronal plane of the spine is more markedly, but the changes of sagittal and cross-section of the spine is less affected, the spine is mainly compensated by the coronal plane bending at second order.
目的： 分析站立、行走状态下对脊柱和骨盆姿态的影响及其代偿规律。 方法： 2017年1至4月温州医科大学数字化医学研究所和温州医科大学附属第一医院骨科选取44名年龄在46～79岁志愿者，通过Rasterstereography仪器进行背部脊柱和骨盆进行站立和行走时的检查，其中男20名，女24名。44名正常中老年志愿者穿统一布鞋，定制单个5 mm厚的鞋垫，通过增加鞋垫高度，模拟出双下肢差异(5～30 mm)，应用Rasterstereography仪器进行脊柱和骨盆检查，在站立及行走状态下测量骨盆及脊柱3D体表参数和4D动态参数并作统计学分析。 结果： 站立状态下，随着双下肢差异增加，冠状面骨盆倾斜和矢状面骨盆扭转也随之增加[最大值约(10.6±4.3) mm、(3.3±3.5)°]，但横断面骨盆旋转变化很小；而冠状面脊柱最大偏移距离也随之增加[最大值约(11.1±17.9) mm]，但矢状面脊柱偏移及横断面椎体表面旋转角度变化均很小。行走状态下，骨盆左、右旋转最大角度及椎体表面左、右旋转最大角度变化均很小，但冠状面脊柱向左、右最大偏移距离随着双下肢差异增加而增加[最大值约(9.8±5.1)、(10.4±6.9) mm]。 结论： 双下肢不等长对骨盆冠状面和矢状面影响较明显，但对骨盆横断面影响甚微。骨盆通过其冠状面倾斜距离、矢状面扭转角度的增加进行一次代偿。同样，对脊柱冠状面影响较明显，但对脊柱矢状面及横断面影响较小，脊柱主要通过冠状面弯曲进行了二次代偿。.
Keywords: Leg; Length inequality; Pelvic tilt; Pelvic torsion; Spine offset.