Shriners Hospitals for Children, Salt Lake City, UT 84103, USA.
Gait Posture. 2012 Apr;35(4):547-55. doi: 10.1016/j.gaitpost.2011.11.022. Epub 2011 Dec 20.
Several multi-segment foot models to measure the motion of intrinsic joints of the foot have been reported. Use of these models in clinical decision making is limited due to lack of rigorous validation including inter-clinician, and inter-lab variability measures. A model with thoroughly quantified variability may significantly improve the confidence in the results of such foot models. This study proposes a new clinical foot model with the underlying strategy of using separate anatomic and technical marker configurations and coordinate systems. Anatomical landmark and coordinate system identification is determined during a static subject calibration. Technical markers are located at optimal sites for dynamic motion tracking. The model is comprised of the tibia and three foot segments (hindfoot, forefoot and hallux) and inter-segmental joint angles are computed in three planes. Data collection was carried out on pediatric subjects at two sites (Site 1: n=10 subjects by two clinicians and Site 2: five subjects by one clinician). A plaster mold method was used to quantify static intra-clinician and inter-clinician marker placement variability by allowing direct comparisons of marker data between sessions for each subject. Intra-clinician and inter-clinician joint angle variability were less than 4°. For dynamic walking kinematics, intra-clinician, inter-clinician and inter-laboratory variability were less than 6° for the ankle and forefoot, but slightly higher for the hallux. Inter-trial variability accounted for 2-4° of the total dynamic variability. Results indicate the proposed foot model reduces the effects of marker placement variability on computed foot kinematics during walking compared to similar measures in previous models.
已经有几种多段式足部模型被报道用于测量足部内在关节的运动。由于缺乏严格的验证，包括临床医生之间和实验室之间的可变性测量，这些模型在临床决策中的应用受到限制。具有彻底量化变异性的模型可能会显著提高对这些足部模型结果的信心。本研究提出了一种新的临床足部模型，其基本策略是使用单独的解剖和技术标记配置和坐标系。解剖学标志和坐标系的识别是在静态受试者校准期间确定的。技术标记位于动态运动跟踪的最佳位置。该模型由胫骨和三个足部段（后足、前足和大脚趾）组成，三个平面计算节段间关节角度。在两个地点（地点 1：由两名临床医生对 10 名受试者，地点 2：由一名临床医生对 5 名受试者）对儿科受试者进行了数据收集。使用石膏模具方法通过允许每个受试者的每个会话之间直接比较标记数据来量化静态临床医生内和临床医生间标记放置变异性。临床医生内和临床医生间关节角度变异性小于 4°。对于动态步行运动学，踝关节和前足部的临床医生内、临床医生间和实验室间变异性小于 6°，但大脚趾稍高。试验间变异性占总动态变异性的 2-4%。结果表明，与以前模型中的类似措施相比，所提出的足部模型减少了标记放置变异性对步行时计算的足部运动学的影响。
