Validity and reliability of an iPad with a three-dimensional camera for posture imaging

Area of Science:

• Biomechanics
• Medical Technology
• Rehabilitation Science

Background:

• Accurate quantification of static posture is essential for evaluating interventions like physical therapy and surgical treatments.
• Traditional motion analysis systems are costly and require specialized expertise, limiting their accessibility.
• A simpler, more accessible method for static posture assessment is needed in clinical settings.

Purpose of the Study:

• To assess the validity and inter/intra-rater reliability of using an iPad with a 3-D camera for evaluating posture and postural deformities.

Main Methods:

• A 3-D model of lying posture was generated using an iPad with a 3-D camera.
• This iPad-based model was compared against a gold-standard Qualisys motion analysis system.
• Distance and angle measurements were taken from markers on the trunk and leg, captured by both systems.

Main Results:

• Intra-class correlation coefficients exceeded 0.98 for all measurements.
• The highest systematic error observed was 4.3 mm for length measurements.
• The highest systematic error for angle measurements was 0.2°.

Conclusions:

• An iPad with a 3-D camera provides a valid and reliable method for quantifying static posture.
• This technology offers a cost-effective solution for posture assessment in clinical environments.