Schache Anthony G, Baker Richard
Hugh Williamson Gait Laboratory, Royal Children's Hospital, Parkville, Vic., Australia.
Gait Posture. 2007 Mar;25(3):440-52. doi: 10.1016/j.gaitpost.2006.05.018. Epub 2006 Sep 29.
The purpose of the current study was to examine the effect of different reference frames on lower limb joint moments during gait with a view to identifying a recommended convention for clinical purposes. Data were collected from 10 subjects (nine able-bodied adults and one child with diplegic cerebral palsy) whilst walking at a self-selected speed. Calculations utilised a three-dimensional inverse dynamics model. For each joint, moments were expressed in four different reference frames. Three of the frames were orthogonal: laboratory frame; anatomical frame of proximal segment; anatomical frame of distal segment. The fourth reference frame was a non-orthogonal joint coordinate system (JCS). Significant differences in the joint moment profiles during gait were found with alternative references frames. This was apparent primarily for the transverse plane joint moments for able-bodied adult gait. For the pathological gait pattern presented, there were also marked differences in the frontal plane joint moments and more subtle ones in the sagittal plane. Whilst it is recognised that all possible reference frames for the expression of the net moment vector are mathematically valid, a decision needs to be made as to which one is more clinically useful. It is proposed that the non-orthogonal JCS is most logical on the basis of what, biomechanically, the joint moment actually represents.
本研究的目的是研究不同参考系对步态期间下肢关节力矩的影响，以期确定一种适用于临床的推荐惯例。以自选速度行走时，从10名受试者（9名健全成年人和1名双侧瘫脑瘫儿童）收集数据。计算采用三维逆动力学模型。对于每个关节，力矩用四种不同的参考系表示。其中三个参考系是正交的：实验室参考系；近端节段的解剖参考系；远端节段的解剖参考系。第四个参考系是一个非正交关节坐标系（JCS）。发现使用不同的参考系时，步态期间关节力矩曲线存在显著差异。这在健全成年人步态的横断面关节力矩中最为明显。对于所呈现的病理步态模式，额状面关节力矩也存在明显差异，矢状面的差异则较为细微。虽然人们认识到表达净力矩矢量的所有可能参考系在数学上都是有效的，但需要决定哪一个在临床上更有用。基于关节力矩在生物力学上实际代表的意义，建议非正交关节坐标系最为合理。
