最佳化人體肢段參數量測法之改進及其於步態中計算身體質量中心運動之應用

Abstract

人體動作分析近年來被廣泛運用在臨床研究中作平衡控制的研究，而身體質量中心是評估平衡控制的重要參數，身體質量中心的準確性已成為不可忽略的課題。身體質量中心是由人體量測學所測得的肢段參數來估算出來的，因此人體量測學的準確性決定了身體質量中心的準確性。 目前常用來估算身體肢段參數的方法大致上可分為三種：估算法、數學模型法以及醫學影像法。以往的方法都有一些缺點，如：使用上受限於特定族群、耗費大量時間或金錢以及輻射傷害等。因此本實驗室提出一個新的使用最佳化來求得個人化身體肢段參數的方法(Chen, Hsieh et al. 2011)，此方法不僅便利、便宜而且不會對人體造成輻射傷害。 本研究之研究目的有三，第一是使用全身核磁共振掃描的方法來驗證Chen(2011)所提出方法求得的肢段參數準確性並加以改進，以及使用在不同體型受試者上的準確性，第二是藉由人為觸診誤差的影響來研究此方法在實驗上的重複性，第三是探討此方法計算出來的身體質量中心在步態分析上的使用性。 從本研究的結果得知，Chen(2011)所提出方法估算出來的肢段參數在不同體型受試者的情況下都有一定的準確性，唯獨在軀幹這個肢段的誤差較大。而本研究則提出模型的修改來加強其準確性，進而也提升了其他肢段的準確性，改進後的方法在估算不同體型受試者的肢段參數上都有很好的準確性；同一施測者及不同施測者的人為觸診誤差，對此改進後以最佳化估算人體肢段參數的影響都不大，因此此方法在實驗上的重複性很好；此方法所計算出來的身體質量中心，在步態分析上的使用性很好，大部分的身體質量中心相關參數誤差都較其他預測法算出來的小，而且所計算出來的結果較不會受到受試者體型不同而有很大的差異。未來在作步態分析時，我們可以推薦使用此方法來估算受試者個人化的肢段參數，能夠得到更準確的動作分析結果。

In recent years, human movement analysis is used to investigate the balance control in clinical research. The accuracy of the body center of mass (COM) is important, because the body COM is the essential parameter in the research of balance control. The accuracy of the anthropometry decided the accuracy of the body COM, because the body COM was calculated from the anthropometric data. There are several methods for estimating the segmental parameters, including prediction equations, medical imaging methods and mathematical modeling methods. The present methods of anthropometry had some limitations, such as population restricted, time-consuming, expensive and radiation- damage. Chen(2011) presented a new optimization-based method (OM) to estimate subject-specific body segment inertial properties. It is a convenient, cheap and radiation-free method. There are three targets for this study. First, validate and improve of the accuracy of the segmental parameters that estimated by OM and investigate the accuracy of OM when estimating the subjects with different BMI by using whole body magnetic resonance scan. Second, investigate the effect of palpation errors on the performance of the OM. Third, study the application of the body COM that calculated by OM during gait. From this study, the segmental parameters that estimated by OM were accurate in most segment, but a little bigger in trunk. This study presented the modification of model to improve the accuracy. The modified OM (MOM) were accurate at estimating segmental parameters in different group of subjects. The intra-rater and inter-rater palpation errors in the segmental parameters estimated by the MOM were found to be quite small, the reliability of MOM is good. The application of the body COM that calculated by MOM during gait were good, especially the errors of the body COM parameters that calculated by MOM were smaller than the result that calculated by other methods in the A/P direction. The BMI of the subjects also won’t affect the result that calculated from the segmental parameters that estimated from the MOM. We can use the MOM to estimated the subject-specific segmental parameters for obtain the more accurate result in gait analysis.