Measuring postural stability with an inertial sensor: validity and sensitivity.

Area of Science:

• Biomechanics
• Sensor Technology
• Human Movement Analysis

Background:

• Postural sway assessment is crucial for understanding balance.
• Existing methods like forceplates and motion capture can be cumbersome.
• Inertial sensors offer a potentially portable and accessible solution for balance assessment.

Purpose of the Study:

• To evaluate the concurrent validity of a novel inertial sensor for measuring postural sway.
• To assess the sensitivity of the inertial sensor to variations in balance tasks.
• To explore the potential application of this sensor in clinical populations, such as those with mild traumatic brain injury.

Main Methods:

• Laboratory-based, repeated-measures study with ten healthy participants.
• Concurrent validity assessed by comparing inertial sensor data with forceplate and rigid-body kinematics.
• Sensitivity evaluated across eight different balance tests with manipulated stance, surface, and visual conditions.

Main Results:

• The inertial sensor demonstrated strong correlations with forceplate (r=0.793) and rigid-body kinematics (r=0.887).
• Significant differences in postural sway were detected across various balance tests.
• Root-mean-square sway increased with task difficulty, from 0.0368 (two legs, eyes-open) to 0.911 (tandem stance, eyes-closed, foam pad).

Conclusions:

• The inertial sensor is a valid and sensitive tool for assessing postural sway in healthy young adults.
• This technology shows potential for future research into balance impairments, particularly in mild traumatic brain injury.
• The sensor's ability to detect subtle balance differences offers new avenues for clinical assessment.