A new process to measure postural sway using a Kinect depth camera during a Sensory Organisation Test

Area of Science:

• Biomechanics
• Human Movement Analysis
• Rehabilitation Technology

Background:

• Posturography quantifies balance and postural control using specialized, often costly, equipment.
• Existing methods for measuring ground reaction forces are not widely accessible due to size and expense.
• There is a need for more affordable and portable solutions for assessing postural control.

Purpose of the Study:

• To propose and validate an alternative posturography method using an inexpensive Kinect depth camera.
• To measure postural sway by tracking the Centre of Mass (CoM) trajectory from skeletal joint data.
• To compare the novel method's results with a gold-standard system, the NeuroCom SMART Balance Master.

Main Methods:

• Utilized the skeletal output from a Kinect depth camera to determine the Centre of Mass (CoM).
• Tracked the relative positions of three key joints to calculate CoM trajectories.
• Conducted a pilot study with 15 healthy individuals performing Sensory Organisation Test (SOT) tasks.
• Compared CoM trajectories and calculated postural sway against the NeuroCom SMART Balance Master using Bland-Altman plots.

Main Results:

• The Kinect-based method demonstrated good agreement with the NeuroCom system for eyes-open tasks on firm support.
• Agreement decreased as Sensory Organisation Test (SOT) tasks became more challenging.
• Discrepancies may stem from differing Centre of Mass (CoM) calculation approaches between the methods.

Conclusions:

• The proposed Kinect-based method provides a foundation for a portable and cost-effective postural control assessment device.
• Further research with larger cohorts, including fall-prone individuals and marker-based validation, is warranted.
• This approach offers a promising, accessible alternative for clinical and research applications in balance assessment.