Head position influence on stabilographic variables.

PURPOSE: Head constitutes 6% of our body weight and significantly influences human body motor system mechanics. From physiological point of view, it should be located at extension of body middle line. Its location being modified results in many consequences in motor system. Our research was aimed at assessing the influence of head position on human body balance stabilographic variables. METHODS: The research was made on a group of 62 patients: 45 women and 17 men, aged from 40 to 60 yrs, 46 yrs on average. Head position in sagittal and frontal plane was assessed with photogrammetric method. Chosen stability parameters were estimated with dynamometric platform PEL 38 and computer software TWIN 99. RESULTS: The results confirmed correlations between existing stabilographic values and head position in frontal plane only. Head position, when changed in this plane, increased the amplitude ( p = 0.001) and average speed of body gravity center trembilng ( p = 0.002). There were no significant relations found in sagittal plane ( p > 0.05). CONCLUSIONS: Our results show that the head position influences stabilographic variables. Its change in frontal plane decreases body posture stability to the largest extent.

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.