Biomechanical influences on head posture and the respiratory movements of the chest.

PURPOSE The head represents 6% of total body weight, therefore it can significantly affect the biomechanics of human posture control, movements and activities. When set out of vertical body axis, head position interferes with the work of the other links in the kinematic chain. The aim of our study was to evaluate the effect of head posture on the breathing activities of the chest. MATERIAL AND METHODS The research was conducted on a group of 65 patients (51 years ± 9.8 years), including 48 women and 17 men. Head posture and chest movements were assessed using a photogrammetric method. RESULTS The results confirmed the existence of a negative correlation between head position in the sagittal plane and movements of lower ribs. Forward head posture resulted in lower amplitude of costal arch motion: for the transverse plane Spearman's R = -0.296, for the frontal plane; -0.273, -0.289. Tilting the head in the frontal plane also influenced the change in the biomechanics of breathing and contributed to a reduction of respiratory movements of the lower ribs Spearman's R = -0.260. CONCLUSIONS Changing the position of the head causes disturbances in the three-dimensional shape of the chest and its respiratory movements.