Measuring Lumbar Motion Angle With a Small Accelerometer: A Reliability Study

Area of Science:

• Biomechanics
• Kinesiology
• Medical Instrumentation

Background:

• Accurate measurement of lumbar motion is crucial for assessing spinal health and function.
• Wearable accelerometers offer a portable and potentially cost-effective method for motion analysis.

Purpose of the Study:

• To evaluate the reliability of lumbar motion angle measurements using accelerometers in the sagittal plane.
• To determine the optimal number of measurements for dependable data acquisition.

Main Methods:

• 102 healthy adults underwent lumbar motion angle assessment using accelerometers placed at key spinal and lower limb locations.
• Measurements included forward/backward trunk bending and prone hip extension.
• Intraclass correlation coefficients and Bland-Altman analysis were employed.

Main Results:

• Intraclass correlation coefficients for intra-examiner reliability ranged from 0.6 to 0.8.
• Inter-examiner reliability showed coefficients from 0.5 to 0.7.
• Systematic biases were noted in trunk forward bending measurements for both intra- and inter-examiner assessments.

Conclusions:

• A single accelerometer measurement is insufficient for reliable sagittal plane lumbar motion analysis.
• Repeating measurements 2-4 times is recommended to achieve adequate reliability.