Balance Assessment using Microsoft Xbox Kinect

Abstract

Reduction in balance has been identified as an indicator of risk of fall, and thus, an accurate and cost effective balance assessment tool is essential for prescribing effective postural control strategies. PURPOSE: To establish the validity of the Microsoft Xbox Kinect (Kinect v2) in assessing the whole body center of mass (CoM) excursion and velocity during single leg balance and voluntary ankle sway tasks among young and elderly subjects. METHODS: Twenty subjects (10 young: age = 20.5±2.3 years, Height = 171.8±7.2 cm, Weight = 70.7±11.6 kg; 10 elderly: age = 70.6±9.5 years, Height = 169.1±8.7 cm, Weight = 74.0±17.8 kg), with no history of lower extremity injury, participated in this study. Subjects performed a total of six randomized trials; four single leg stand (SLS) and two ankle sway trials. A comparison between the balance outcome measures (anteroposterior (AP) and mediolateral (ML) CoM excursion and velocity and average sway length) from the Kinect v2 and a traditional three-dimensional motion analysis (3DMA) system was performed. RESULTS: Results from the SLS and voluntary ankle sway trials showed that consistency, agreement, and correlation between systems was excellent (ICC > 0.75) for all CoM related variables when all subjects were considered a single group as well as when the elderly and young groups were analyzed. Concordance between systems ranged from poor to almost perfect depending on the group, task, and variable assessed. CONCLUSION: This new technique, using a low cost motion analysis technology, may enable real time, objective assessments of balance parameters in the clinical and research environments, which represents a clear advancement in clinical balance assessment and home-based rehabilitation programs.