Reliability of a Measurement Method for Upper Limb Raised Standing Spinal Alignment Using a Smartphone Inclinometer...

Area of Science:

• Biomedical Engineering
• Orthopedics
• Digital Health

Background:

• Smartphone inclinometer apps show promise for measuring spinal curvature.
• Previous research focused on the lumbar spine, with unclear methods for sacral palpation.
• No established methods exist for measuring spinal alignment with upper limb elevation.

Purpose of the Study:

• To assess the reliability and validity of smartphone app-based spinal alignment measurements.
• To evaluate measurements in the raised arm standing posture.
• To investigate thoracic kyphosis and lumbar lordosis angles.

Main Methods:

• 18 healthy adults measured thoracic kyphosis and lumbar lordosis in a raised arm posture.
• Measurements used specific spinous process landmarks (T1/2, T12/L1, L4/L5).
• Inter-rater reliability (ICC) and measurement precision (MDC95) were calculated; validity assessed against an inclinometer using Pearson's correlation.

Main Results:

• High inter-rater reliability for smartphone measurements: ICC 0.92 (thoracic) and 0.90 (lumbar).
• Acceptable precision indicated by MDC95 values (7.00° thoracic, 9.95° lumbar).
• Strong correlations (r > 0.9) between smartphone and inclinometer measurements for both spinal regions.

Conclusions:

• Smartphone inclinometer apps demonstrate good inter-rater reliability for spinal alignment.
• The validity of these smartphone measurements is also confirmed.
• This technology offers a reliable and valid method for assessing spinal alignment in specific postures.