Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno (NO), Fondazione Salvatore Maugeri (IRCCS), Veruno, (NO), Italy.
J Neuroeng Rehabil. 2014 Jun 5;11:95. doi: 10.1186/1743-0003-11-95.
Previous studies have assessed reliability of insole technology for evaluating foot pressure distribution during linear walking. Since in natural motion straight walking is intermingled with turns, we determined the test-retest reliability of insole assessment for curved as well as linear trajectories, and estimated the minimum number of steps required to obtain excellent reliability for each output variable.
Sixteen young healthy participants were recruited. Each performed, two days apart, two sessions of three walking conditions: linear (LIN) and curved, clockwise (CW) and counter-clockwise (CCW). The Pedar-X system was used to collect pressure distribution. Foot print was analyzed both as a whole and as subdivided into eight regions: medial and lateral heel, medial and lateral arch, I metatarsal head, II-V metatarsal heads, hallux, lateral toes. Reliability was assessed by using intraclass correlation coefficient (ICC) for clinically relevant variables from analysis of 50 steps per trajectory: Peak Force (PF); Peak Pressure (PP); Contact Area (CA); Stance Duration (S).
When considering whole-foot, all variables showed an ICC >0.80, therefore highly reliable. This was true for both LIN and curved trajectories. There was no difference in ICC of the four variables between left and right foot. When collapsing foot and trajectories, S had a lower ICC than PP and CA, and PP lower than CA. Mean percent error between the values of first and second session was <5%. When separately considering the eight foot regions, ICCs of PF, PP and CA for all regions and trajectories were generally >0.90, indicating excellent reliability. In curved trajectories, S showed smaller ICCs. Since the least ICC value for S was 0.60 in LIN trajectory, we estimated that to achieve an ICC ≥0.90 more than 200 steps should be collected.
High reliability of insole dynamic variables (PF, PP, CA) is obtained with 50 steps using the Pedar-X system. On the contrary, high reliability of temporal variable (S) requires a larger step number. The negligible differences in ICC between LIN and curved trajectory allow use of this device for gait assessment along mixed trajectories in both clinical and research setting.
先前的研究已经评估了鞋垫技术在评估线性行走时足底压力分布的可靠性。由于在自然运动中，直走会与转弯混合，因此我们确定了鞋垫评估在曲线和直线轨迹中的测试-重测可靠性，并估计了获得每个输出变量的优秀可靠性所需的最小步数。
招募了 16 名年轻健康的参与者。每位参与者在两天的时间内，分别进行了三种行走条件的两次测试：直线（LIN）和曲线，顺时针（CW）和逆时针（CCW）。Pedar-X 系统用于收集压力分布。足迹被作为一个整体和分为八个区域进行分析：内侧和外侧脚跟、内侧和外侧足弓、I 跖骨头部、II-V 跖骨头部、大脚趾、外侧脚趾。通过对每条轨迹的 50 步进行分析，使用组内相关系数（ICC）评估了临床相关变量的可靠性：峰值力（PF）；峰值压力（PP）；接触面积（CA）；支撑期时长（S）。
考虑整个足部时，所有变量的 ICC 均大于 0.80，因此高度可靠。这对于直线和曲线轨迹都是如此。左右脚的四个变量的 ICC 没有差异。当合并足部和轨迹时，S 的 ICC 低于 PP 和 CA，PP 的 ICC 低于 CA。第一次和第二次测试值之间的平均误差百分比小于 5%。当分别考虑八个足部区域时，PF、PP 和 CA 的 ICC 对于所有区域和轨迹通常大于 0.90，表明具有极好的可靠性。在曲线轨迹中，S 的 ICC 较小。由于 S 的最小 ICC 值为 0.60，在直线轨迹中，我们估计要获得 ICC≥0.90，应收集超过 200 步。
使用 Pedar-X 系统，50 步可获得鞋垫动态变量（PF、PP、CA）的高可靠性。相反，S 的时间变量需要更大的步数量才能达到高可靠性。LIN 和曲线轨迹之间 ICC 的微小差异允许在临床和研究环境中沿着混合轨迹使用该设备进行步态评估。
