Background

Although functional methods determining the hip joint center (HJC) are becoming increasingly popular, no systematic investigation has been conducted yet to assess the reliability of functional hip joint calibration in patients with cerebral palsy (CP).

Research question

What is the most reliable way to conduct functional calibration motions for estimating HJC location in children with CP and movement disorders?

Methods

Twenty-two patients with CP were included in the study. A marker set for Plug-in Gait with additional cluster markers was used. Two functional calibration movements, including a new movement, were proposed and tested with one and three repetitions each. Functional HJCs were determined using the SCoRE approach and compared to results obtained by applying the conventional regression method for assessing face validity.

Results

The choice of calibration movement had significant impact on SCoRE residuals and HJC location. Increasingly repeating calibration movements did not improve results. A modified star movement by allowing the toes to tip the ground provided the most reliable data and is feasible for children with GMFCS level I-III. The feasibility of the method is further improved by analyzing hip motion in the contralateral stance limb and, among the calibration movements, gave the most precise HJC estimation.

Significance

Type and performance of the functional calibration movement is one key factor for determining a robust HJC. Analyzing the data in the stance leg via the modified star motion yielded robust and reasonable results for the HJC location, which should be validated in further studies that include imaging methods. Using one repetition instead of three seems promising in terms of feasibility for patients with movement disorder.

中文翻译：

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脑瘫患儿髋关节功能中心测定

背景

尽管确定髋关节中心 (HJC) 的功能方法正变得越来越流行，但尚未进行系统调查来评估脑瘫 (CP) 患者功能性髋关节校准的可靠性。

研究问题

进行功能校准运动以估计 CP 和运动障碍儿童的 HJC 位置的最可靠方法是什么？

方法

22 名 CP 患者被纳入研究。使用带有附加集群标记的 Plug-in Gait 标记集。两个功能校准运动，包括一个新的运动，被提出并测试了一个和三个重复。使用 SCoRE 方法确定功能性 HJC，并与应用传统回归方法获得的结果进行比较，以评估表面效度。

结果

校准运动的选择对 SCoRE 残差和 HJC 位置有显着影响。越来越多地重复校准运动并没有改善结果。通过允许脚趾倾斜地面而修改的星形运动提供了最可靠的数据，并且对于 GMFCS 级别 I-III 的儿童是可行的。通过分析对侧站立肢体的髋关节运动，进一步提高了该方法的可行性，并在校准运动中给出了最精确的 HJC 估计。

意义

功能校准运动的类型和性能是确定稳健 HJC 的关键因素之一。通过修改后的恒星运动分析站立腿中的数据为 HJC 位置产生了可靠且合理的结果，这应在包括成像方法在内的进一步研究中得到验证。就运动障碍患者的可行性而言，使用一次而不是三次重复似乎很有希望。