Brown Kathryn M, Bursey Diane E, Arneson Laurie J, Andrews Catherine A, Ludewig Paula M, Glasoe Ward M
Program in Physical Therapy, University of Minnesota, Minneapolis, MN 55455, USA.
J Biomech. 2009 Jun 19;42(9):1263-9. doi: 10.1016/j.jbiomech.2009.03.013. Epub 2009 Apr 17.
This study investigated whether points digitized for the purpose of embedding coordinate systems into the foot accurately represented the orientation of the bone described. Eight complete data sets were collected from 9 adult cadaver specimens. Palpable landmarks defined 5 segments to include the calcaneus, navicular, medial cuneiform, first metatarsal, and hallux. With use of the Flock of Birds electromagnetic motion tracking device, a single examiner digitized a minimum of 3 points for each segment. Coordinate definitions followed the right-hand rule, with left-sided data converted to right-sided equivalency. Local axes were created where X projected approximately forward, Y upward, and Z laterally. Matrix transformation computations calculated the angular precision in degrees between coordinates built from points digitized pre- and post-dissection of surface tissues covering bone. The condition of post-dissection was considered the criterion standard for comparison. Change about the X-axis represented the angular precision of the coordinate in the frontal anatomical plane; Y-axis in the transverse plane; Z-axis in the sagittal plane. The calcaneus and navicular coordinate axes changed by an average of <3 degrees across conditions. Mean coordinate angulation of the cuneiform X, Y, Z axes changed by 6.0 degrees , 4.6 degrees , 11.9 degrees , respectively. Change in coordinate angulation was largest for the X-axis at the first metatarsal (48.6 degrees ) and hallux (36.5 degrees ). A two-way repeated measures ANOVA found a significant interaction between the axis and segment (F=8.87, P=0.00). Tukey post-hoc comparisons indicated the change in coordinate angulation at the X-axis for the cuneiform, metatarsal, and hallux to be significantly different (P <0.05) from the calcaneus and navicular. The X-axis of the first metatarsal and hallux was different from all other axis-segment combinations except for the Z-axis of the cuneiform. Differences in locating landmarks reduced angular precision of the coordinate axes most in the smallest foot segments where points digitized were located close together. We can recommend the proposed landmarks for the calcaneus and navicular segments, but kinematics determined about the coordinate axes for the small sized medial cuneiform, and the long (X) axis for the first metatarsal and hallux have excessive error.
本研究调查了为将坐标系嵌入足部而数字化的点是否准确代表了所描述骨骼的方向。从9个成年尸体标本中收集了8组完整的数据。可触及的标志点定义了5个节段，包括跟骨、舟骨、内侧楔骨、第一跖骨和拇趾。使用鸟群电磁运动跟踪设备，一名检查者为每个节段至少数字化3个点。坐标定义遵循右手定则，左侧数据转换为右侧等效数据。创建局部坐标轴，其中X大致向前投影，Y向上投影，Z横向投影。矩阵变换计算从覆盖骨骼的表面组织解剖前和解剖后数字化的点构建的坐标之间以度为单位的角精度。解剖后的情况被视为比较的标准。绕X轴的变化代表坐标在额状解剖平面内的角精度；Y轴在横断平面内；Z轴在矢状平面内。跟骨和舟骨坐标轴在不同条件下平均变化<3度。楔骨X、Y、Z轴的平均坐标角度分别变化了6.0度、4.6度、11.9度。第一跖骨（48.6度）和拇趾（36.5度）处坐标角度的变化在X轴上最大。双向重复测量方差分析发现轴和节段之间存在显著交互作用（F = 8.87，P = 0.00）。Tukey事后比较表明，楔骨、跖骨和拇趾在X轴上的坐标角度变化与跟骨和舟骨有显著差异（P <0.05）。第一跖骨和拇趾的X轴与除楔骨Z轴外的所有其他轴 - 节段组合不同。在数字化点靠得很近的最小足部节段中，地标定位的差异最大程度地降低了坐标轴的角精度。我们可以推荐所提议的跟骨和舟骨节段的地标，但关于小尺寸内侧楔骨的坐标轴以及第一跖骨和拇趾的长（X）轴所确定的运动学存在过大误差。
