Comparing 3D foot scanning with conventional measurement methods

Abstract

Background: Foot dimension information on different user groups is important for footwear design and clinical applications. Foot dimension data collected using different measurement methods presents accuracy problems. This study compared the precision and accuracy of the 3D foot scanning method with conventional foot dimension measurement methods including the digital caliper, ink footprint and digital footprint. Methods: Six commonly used foot dimensions, i.e. foot length, ball of foot length, outside ball of foot length, foot breadth diagonal, foot breadth horizontal and heel breadth were measured from 130 males and females using four foot measurement methods. Two-way ANOVA was performed to evaluate the sex and method effect on the measured foot dimensions. In addition, the mean absolute difference values and intra-class correlation coefficients (ICCs) were used for precision and accuracy evaluation. The results were also compared with the ISO 20685 criteria. Results: The participant's sex and the measurement method were found (p < 0.05) to exert significant effects on the measured six foot dimensions. The precision of the 3D scanning measurement method with mean absolute difference values between 0.73 to 1.50 mm showed the best performance among the four measurement methods. The 3D scanning measurements showed better measurement accuracy performance than the other methods (mean absolute difference was 0.6 to 4.3 mm), except for measuring outside ball of foot length and foot breadth horizontal. The ICCs for all six foot dimension measurements among the four measurement methods were within the 0.61 to 0.98 range.

Comparison of 3D scanning versus traditional methods of capturing foot and ankle morphology for the fabrication of orthoses: a systematic review

“…We attempted meta-analysis on pooled measurements of foot parameters collected from 3D scanning and traditional methods. Three studies [23][24][25] provided raw measurements for parameters of the foot such as arch height, rearfoot width and forefoot width. However, due to heterogeneity in data capture methods we were unable to conduct the meta-analysis (Additional file 2).…”

“…One additional article was found after a hand search of the references. The six studies included one randomised controlled trial evaluating AFOs [26], four studies reporting reliability and accuracy of 3D scanning for FOs [23][24][25]27], and two studies assessing speed of 3D scanning for FOs and AFOs [25,28] (Table 1). Traditional foot and ankle capture tools included in the studies were plaster cast, foam impression, digital footprint, ink footprint and 3D scanning.…”

“…The six studies included 189 adults (102 female, 86 male, and 1 unspecified) [23-25, 27, 28] and 134 children (59 girls, 75 boys) [23,24,26,27]. The mean age and SD of the participants in the included studies were 23.8 years, SD 3.6 [23], 35.4 years, SD 13.6 [24], 42.8 years, SD 11.4 [27], males 21.2 years, SD 2.1 and females 21 years SD 5.9 [25], males 10.7 years SD 4.9 females 9.8 years SD 4.1 [26] and not reported [28]. The sample size for the studies were n = 15 [23], n = 21 [24], n = 22 [27], n = 130 [25], n = 134 [26] and n = 1 [28].…”

Foot shape prediction using elliptical Fourier analysis

“…12,13 Currently, several laser-based 3D foot scanners have become commercially available, by which detailed information on 3D foot shape and dimensions can be obtained. 14,15 However, these scanners are usually expensive, and are mainly used in research areas such as medical applications. 16,17 To address this issue, our goal was to develop a new method to reconstruct the 3D foot shapes by using only their 2D inputs.…”

Automatic foot scanning and measurement based on multiple RGB-depth cameras

“…Several laser-based foot scanners are commercially available by which detailed 3D foot shape and dimensions can be obtained. 1,2 However, there are two main problems with them. Firstly, these scanners are usually very expensive and difficult to maintain.…”