Fig. 2

Comparison of kinematic measurements of head motion during balance exercises between A preoperative VS subjects and healthy controls, B postoperative VS subjects and healthy controls, C preoperative and postoperative VS subjects. The kinematic measurements are arranged horizontally. The 10 exercises are arranged vertically and categorized into 3 groups: (i) tandem (purple), (ii) eyes-closed (yellow), and (iii) unstable surface (green). Asterisks indicate significance differences between two groups (*: < 0.05, ** < 0.01, and ***: < 0.001)