The possibilities of change registration of mechanical properties of human axial system as a result of hypo-hyperkinetic strainregime
Abstrakt
Experimental study considers determination of change in transfer of vibratory load through human axial system as a result of monotonous stress, changes of form, tissues and weigh change during pregnancy and in hypo-hyperkinetic exercising regime of rhythmic gymnasts (RG). Experiment took place in two different strain regimes - in regime before and after the long-term monotonous load during car drive and before and after training strain of RG.
The method of detection was TVS (transfer of vibration through spine). The TVS is based on application of ? excitation pulses with half-length 5ms and then harmonic excitation continuously periodically changing from 5 Hz to 160 Hz on C7 and L5 vertebrae.
This wave is transferred along the axial system. The acceleration of all the spinous tips of the vertebrae, along which the waves spread between C7 and S1, is detected by accelerometric sensors.
Recent results of measurements proved, that due to the hypo-hyperkinetic strain, the transfer characteristics of mechanical waves through axial system of studied subject are changing. After both vibration and physical load there is a more significant dampening of the spinal tissues apparent, i.e. lower acceleration amplitude.
The tissues resonance frequency also shifts towards the lower value. On the other hand after long lasting relaxation on a bed an opposite tendency showed, the acceleration amplitude was higher, tissues were relaxed and dampening was lower.
The same tendency manifested among the pregnant women. The results show changes in mechanical properties of examined tissues before and after vibration or other type of load.