Visual feedback increases chest wall mobility measure: A cross-sectional study

Abstract Background: Visual feedback could optimize the evaluation of chest wall mobility. Objective: To compare chest wall mobility performed with and without visual feedback. Methods: Cross-sectional study, 64 healthy volunteers, average age 24 years old. The thorax circumference was measured at two locations, the axillary and xiphisternum regions, by a tape placed at the anterior axillary line and at the xiphoid process. The evaluations were performed: (i) after verbal explanation (without visual feedback), (ii) after verbal explanation plus visual feedback (with visual feedback); for this evaluation the volunteer remained in front of the computer, which provides visual feedback. Results: There was no difference between axillary measurement with vs. without feedback (7.5 ± 2.4 cm vs. 7.9 ± 3.3 cm, respectively, p = 0.215), but significant difference between xiphisternum measurement 7.1 ± 2.7cm with feedback vs. 6.5 ± 2.3cm without feedback, p = 0.043. Low intraclass correlation coefficients were observed for the axillary measurement [0.51 (0.19–0.72, p = 0.003) and for xiphisternum measurement [0.60 (0.35–0.76, p < 0.001) performed with and without feedback, respectively. Conclusion: Thoracic mobility presents great variability when compared with and without feedback, so the visual stimulus must be taken into account in this evaluation.