Objective: To compare agreement and intra-class correlation of King-Devick (K-D) Balance versus Sway Balance mobile applications. Background: Balance assessments are essential in concussion evaluation due to the high incidence of post-concussion balance deficits. Traditional modified Balance Error Scoring System is highly subjective. Objective quantitative balance evaluations K-D Balance and Sway Balance should be explored. Methods: Seventy subjects examined at UT Southwestern Medical Center underwent simultaneous K-D Balance and Sway-Balance assessments. Intra-class correlation coefficient (ICC) assesses test retest reliability of K-D Balance. Linear regression analysis and Bland-Altman Plot evaluate the agreement between K-D Balance and Sway Balance scores. Results: K-D Balance and Sway Balance scores showed no statistical difference (K-D 96.0±10; Sway 95.7±11; p = 0.379). ICC between K-D Balance scores was 0.71. Linear regression analysis demonstrated a significantly high correlation between the two balance devices (R2 = 0.926, p < 0.001). Bland-Altman Plot showed majority of data points fall within 95% limits of agreement. Conclusion: K-D Balance and Sway Balance showed a statistically significant level of agreement, each providing objective measures of balance performance and allowing clinicians to both quantify balance performance and to monitor balance over time.

Summary Points:

  • Compared the agreement between K-D Balance versus Sway Balance, which are both objective balance assessments as mobile applications.
  • There was a high level of correlation between the two balance tests.
  • Utilizing quantitative balance measures will likely prove helpful in assessing and monitoring balance over time.