# Special Issue \"Novel Approaches and Applications in Ergonomic Design\"
## 8 A Boundary Zone Method for the Generation of Multivariate Representative Humanoids  
A small group of digital humanoids that properly represent the target population are used in the ergonomic design and evaluation of products and workstations in a digital environment. [PERSON] et al. [7] proposed a novel multivariate method that generates representative humanoids (RHs) at a boundary zone (BZ), employing cluster analysis and real anthropometric cases to overcome the limitations of existing multivariate methods (factor analysis and principal component analysis), such as, the loss of anthropometric variability, the large estimation error of anthropometric dimensions (ADs), and a lack of body size diversity. The BZ method consists of three steps: (1) the formation of a BZ for a designated accommodation percentage of the target population, (2) the clustering of anthropometric cases in the BZ, and (3) the selection of representative cases from anthropometric clusters as RHs. The proposed BZ method was preferred to the existing multivariate methods. This was evaluated using 1988 U.S. Army anthropometric data and 10 ADs pertinent to computer workstation design in terms of the loss of anthropometric variability to determine the estimation error of ADs and the lack of body size diversity. Further research is needed to examine the effectiveness of the BZ method in solving various ergonomic design problems.  
Test-Retest Reliability of Sole Morphology Measurements Using a Novel Single-Image-Based Pin-Array Impression Reconstruction Method  
Existing sole morphology assessment methods are limited to the two-dimensional or non-weight-bearing conditions of the foot. [PERSON] et al. [8] evaluated the reliability of the novel Single-Image-Based Pin-Array Impression Reconstruction (SIBPAIR) method when implemented on a commercial foot assessment system. In the study, the SIBPAIR method was found to have high intra-rater, inter-rater, and inter-session reliabilities (ICC > 0.90) by analyzing repeated measurements of 3D morphological sole scans from 15 healthy young adults by two physical therapists. Accurate and reliable measurements of the sole morphology could be used for foot assessments and subsequent applications, such as designing and manufacturing customized shoes and orthoses.  
Development of a Drawing Application for Communication Support during Endoscopic Surgery and Its Evaluation Using Steering Law  
Computer-Supported Collaborative Work (CSCW) environments, using augmented reality (AR) technology, are expanding to various fields, including industry, education, and health sectors. [PERSON] et al. [9] constructed a hands-free endoscopic surgical CSCW system that enables head movements to draw lines in space using AR technology and evaluated the applicability of the drawing motion using head movements to the steering law for its' potential use during endoscopic surgery. In the study, nine participants aged between 21 and 25 manipulated a cursor through a pathway using head movements. Data regarding the movement time (MT), the number of errors, and subjective evaluation of the difficulty of the task were collected in the study. A strong linear relationship (\(R^{2}\) > 0.9) between the index of difficulty (ID), MT, and higher performance was reported in the horizontal and vertical directions compared to that of the diagonal directions. Although the weight and biocompatibility of the AR glasses of Microsoft HoloLens need to be resolved for use in a clinical setting, the study demonstrates the potential of an AR-based head-drawing system for endoscopic surgery in a CSCW environment.