School of Health, Sport and Bioscience, University of East London, Stratford, London E15 4LZ, England.
J Foot Ankle Res. 2013 Oct 31;6(1):43. doi: 10.1186/1757-1146-6-43.
Various foot models are used in the analysis of foot motion during gait and selection of the appropriate model can be difficult. The clinical utility of a model is dependent on the repeatability of the data as well as an understanding of the expected error in the process of data collection. Kinematic assessment of the paediatric foot is challenging and little is reported about multi-segment foot models in this population. The aim of this study was to examine three foot models and establish their concurrent test-retest repeatability in evaluation of paediatric foot motion during gait.
3DFoot, Kinfoot and the Oxford Foot Model (OFM) were applied concurrently to the right foot and lower limb of 14 children on two testing sessions. Angular data for foot segments were extracted at gait cycle events and peaks and compared between sessions by intraclass correlation coefficient (ICC) with 95% confidence intervals (95%CI) and standard error of measurement (SEM).
All foot models demonstrated moderate repeatability: OFM (ICC 0.55, 95% CI 0.16 to 0.77), 3DFoot (ICC 0.47, 95% CI 0.15 to 0.64) and Kinfoot (ICC 0.43, 95% CI -0.03 to 0.59). On the basis of a cut-off of 5°, acceptable mean error over repeated sessions was observed for OFM (SEM 4.61° ± 2.86°) and 3DFoot (SEM 3.88° ± 2.18°) but not for Kinfoot (SEM 5.08° ± 1.53°). Reliability of segmental kinematics varied, with low repeatability (ICC < 0.4) found for 14.3% of OFM angles, 22.7% of 3DFoot angles and 37.6% of Kinfoot angles. SEM greater than 5° was found in 26.2% of OFM, 15.2% of 3DFoot, and 43.8% of Kinfoot segmental angles.
Findings from this work have demonstrated that segmental foot kinematics are repeatable in the paediatric foot but the level of repeatability and error varies across the segments of the different models. Information on repeatability and test-retest errors of three-dimensional foot models can better inform clinical assessment and advance understanding of foot motion during gait.
在步态分析中，人们使用各种足部模型，而选择合适的模型可能具有一定难度。模型的临床实用性取决于数据的可重复性以及在数据采集过程中对预期误差的理解。儿童足部运动的运动学评估具有挑战性，关于该人群的多节段足部模型，目前的研究报道较少。本研究的目的是检验三种足部模型，并确定它们在评估儿童步态中足部运动时的重复测试-再测试可重复性。
在两次测试中，将 3DFoot、Kinfoot 和牛津足部模型（Oxford Foot Model，OFM）同时应用于 14 名儿童的右脚和下肢。在步态周期事件和峰值处提取足部各节段的角度数据，并通过组内相关系数（intraclass correlation coefficient，ICC）及其 95%置信区间（95% confidence intervals，95%CI）和测量标准误差（standard error of measurement，SEM）进行两次测试间的比较。
所有足部模型的重复性均为中度：OFM（ICC 0.55，95%CI 0.16 至 0.77）、3DFoot（ICC 0.47，95%CI 0.15 至 0.64）和 Kinfoot（ICC 0.43，95%CI -0.03 至 0.59）。基于 5°的截断值，OFM（SEM 4.61°±2.86°）和 3DFoot（SEM 3.88°±2.18°）的多次测试中可接受的平均误差较小，但 Kinfoot 则不然（SEM 5.08°±1.53°）。节段运动学的可靠性存在差异，OFM 的角度中，有 14.3%的重复性较差（ICC<0.4），3DFoot 的角度中有 22.7%，Kinfoot 的角度中有 37.6%。OFM 的 26.2%、3DFoot 的 15.2%和 Kinfoot 的 43.8%的节段角度的 SEM 大于 5°。
本研究结果表明，儿童足部的节段运动学具有可重复性，但不同模型各节段的重复性和误差水平存在差异。有关三维足部模型的可重复性和测试-再测试误差的信息可以更好地为临床评估提供依据，并加深对步态中足部运动的理解。
