Test-Retest Reliability of 3D Scanning Devices for Measuring Lower Limb Volume

Research Objectives: To investigate the test-retest reliability of commercially available handheld body scanners for the measurement of lower limb volume.

Design: Cross-sectional study.

Setting: All procedures were conducted in a university laboratory.

Participants: A convenience sample of ten healthy individuals with no lower limb open wounds (6 female, mean age = 24.9±1.6, mean body mass index 22.9±3.4) started and completed all testing.

Interventions: Not applicable.

Main Outcome Measures: A single lower limb was assessed by water displacement (WD) and 3D volumetric scanning using two different commercially available handheld units (BodyScan® [BS] and Structure Sensor® [SS]). Measurements were concurrently collected on two separate occasions separated by a minimum of 48 hours. For the water displacement measure, which is the widely accepted measurement standard, participants placed their test limb in a custom volumetry tank, submerging to 10 cm above the center of the patella, and the displaced water was measured in liters. For the 3D scanning, participants stood motionless while both 3D scanners instrument were used to fully scan the lower limb with care taken to obtain full surface coverage and later derive volume in liters. Test-retest reliability from the two sessions was assessed with the intraclass correlation coefficient (ICC, 3,1).

Results: WD had a ICC value of 0.93 (95% confidence interval [CI], 0.76 – 0.98), BS had a ICC value of 0.97 (95% CI, 0.90 – 0.99) and SS had a ICC value of 0.95 (95% CI, 0.78 - 0.99).

Conclusions: Lower limb volume measurements taken by water displacement and 3D handheld scanners exhibited excellent (ICC > 0.90) test-retest reliability. Longitudinal research studies in assessing limb volume changes in clinical populations is warranted.

Author(s) Disclosures: No conflicts.