engleski

Development of Computer System for Digital Measurement of Human Body: Initial Findings

Background: Microsoft Kinect is used in the field of anthropometry (Sameijma et al., 2012 ; Xu et al., 2013 ; Clarkson et al., 2016 ; Zhang et al., 2015), gait analysis (Springer & Seligman, 2016 ; Pfister et al., 2014 ; Motiian et al., 2015 ; Prochazka et al., 2015 ; Cippitelli et al., 2015), motor performance (Lim et al., 2015 ; Sevick et al., 2016 ; Taha et. al., 2016), posture/balance evaluation (Dutta et al., 2014 ; Metiplay et al., 2013 ; Oh et al., 2014 ; Saenz-de-Urturi & Garcia- Zapirain Soto, 2016) and rehabilitation (Galna et al., 2014 ; Mobini et al., 2015 ; De Rosario et al., 2014 ; Shapi’i et al., 2015). Reliability of instruments in clinical and sport application differ, therefore the goal of this research was to initially determine the protocol of validation of a new measuring instrument for digital measurement of anthropometric dimensions of the body structural and metric). Reliability of results in this paper was tested on three classically and digitally measured anthropometric variables, i.e. height, left forearm length and left lower leg length. Methods: Male and female employees of the Technology Park Zagreb (N=52) volunteered for this research. Subjects were wearing their everyday clothes. Among 471 assessed variables (3 + ((26 * 6)) * 3) three variables from a set of classically measured anthropometric dimensions were extracted - height, length of left forearm and length of left lower leg. Classical measurements were conducted through standard IBP protocols, a Standardized protocol for digital measurement (DM- I) was produced. Data were analyzed by Statistica 12 for Windows operating system. Mean, standard deviation, range, variability coefficient, skewness and kurtosis were used as descriptive parameters, as well as Pearson correlation coefficient, Spearman-Brown alpha, Cronbach`s alpha and Spearman-Brown (standardized) alpha. Results: Classically and digitally measured height in average results do not differ significantly, while for lengths of the left forearm and the left lower leg do indicate significant differences (lower values). The differences could be attributed to different reference points used in two measurement methods. Measures of internal consistency (reliability) for digitally measured variables:height of the body, length of left forearm and length of left lower leg demonstrate high reliability (Cronbach alpha, the standardized alpha 0.995 to 0.997) and the average inter-item correlation (0.973 to 0.985), indicates a high internal consistency between items related to digitally measured height. Reliability was slightly lower for digitally measured length of the left forearm and lower leg due to greater differentiation in average interitem correlations coefficients. Conclusions: Digital measurements with Kinect are not appropriate for clinical trials demanding high precision. There is no statistical evidence that could differentiate distances of examinee from Kinect sensor in order to define optimal distance (as long as subject stands within Kinects range. Small errors occur due to clothing, possibly due to illumination, and sensor height and distance, which is in line with previous research.

Anthropometry ; Measurement Reliability ; Kinect ; Protocol Modelling

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