Foot Measurements From Three-Dimensional Scans: Elinvision 3DST Reliability

Area of Science:

• Biomechanics
• Podiatry
• Medical Device Technology

Background:

• Traditional plaster casting for orthotics and therapeutic footwear is time-consuming.
• 3D foot scanners offer a potentially faster alternative for capturing foot dimensions.

Purpose of the Study:

• To evaluate the reliability of the Elinvision 3DST foot scanner for key foot measurements.
• To compare 3D scanner measurements with traditional manual measurements.

Main Methods:

• A repeated measures design was employed.
• Two raters performed three scans of the right foot for 20 healthy adults using the 3DST scanner.
• Manual measurements were taken by an experienced rater using a Ritz stick and tape measure.

Main Results:

• Excellent inter-rater and intra-rater reliability (Intraclass Correlation Coefficients 0.99-1.00) were observed for the 3DST scanner.
• Scanner and manual measurements showed high agreement for foot length, ball width, heel width, and ball girth (≤0.4 cm difference).
• Larger discrepancies were found for foot waist, short heel, ankle circumference, and anatomical ball width (0.5-1.1 cm difference).

Conclusions:

• The 3DST scanner demonstrates high reliability and potential for capturing basic foot dimensions in footwear fit research.
• Significant differences in specific measurements limit its current application in the production of custom orthotics and therapeutic footwear.