Whole body vibration involves the exposure of the entire human body to direct contact with environmental vibration. Chronic mechanical vibrations, combined with the physical attributes of the human body, can amplify the incoming energy and present the potential for negative health effects. Vibration exposure can, thus, result in adverse health effects such as spinal injuries, abdominal neurological and cardiovascular disorders. These can manifest indirectly as an accident causal factor. The aim of our research is to study the impact of vibration fluctuations of different frequencies on the structural and functional condition and mechanisms of bone remodelling. An experimental study was, therefore, conducted on mature male rats. For assessment of bone metabolism in the venous blood of rats, osteocalcin level was determined, while fragments of rats’ lumbar vertebrae were subsequently taken for histologic examination. Our work revealed that with the increase of vibration frequency, an increase of osteocalcin level in the blood of experimental animals comes about. Moreover, we noted after terminating vibration fluctuations on the 56th day of the experiment, osteocalcin levels are gradually reduced. In addition, in the course of histological study of specimens of lumbar vertebrae bone tissue, even as early as of the 28th day of the experiment, evidences of acute impairment of the bone tissue and initial signs of its remodelling are clearly traced. Indeed, on the 56th day, the remodelling processes represented by enhanced regeneration in the zone of the cartilage plate, increased in proliferation activity. We also saw hyperplasia of chondrocytes, hypertrophy of the respective zones of cartilage tissue, zones of forming immature bone tissue on the areas of previous damage, focal replacement fibrosis and angiomatosis. Hence, with increasing vibratory acceleration of 0,5 g, the rate of bone metabolism grows, osteoblast activation processes are accelerated and the impairment of collagen and calcium loss is increased. All this leads subsequently to the occurrence of osteoporosis.

Study of the influence of vibration oscillations of different frequency, amplitude and vibration acceleration on the structural and functional state and mechanisms of muscle tissue remodelling. An experimental study was conducted on sexually mature male rats. The rats of the four experimental groups were subjected to vertical vibration oscillations of 15, 25, 50 and 75 Hz, respectively. It has been established that pathological changes in muscle tissue in the form of different variants of damage and remodelling tend to increase, which correlates with the frequency of vibration, amplitude and vibration acceleration level, as in the 2nd group, where the maximum permissible vibration levels did not exceed the established allowable norms, and in other groups of animals, where the permissible levels of total vibration were exceeded. By increasing vibration acceleration for more than 1.25 m/s2 (0.13 g, frequency more than 25 Hz and amplitude of 2 mm), severe damages are observed in the form of alterative changes of muscle fibres with the disappearance of transverse strain, homogenization of sarcoplasm, fragmentation with dissociation fibres on separate beams, partial and subtotal myocytolysis, and necrosis of separate fibres. Inflammation is rapidly increasing with the increase in the frequency of vibration and the level of vibration acceleration for more than 5.0 m/s2 (0.51 g).

Objectives Osteoporosis often occurs in individuals of different age groups, frequently during menopause and after ovariectomy. It increases the risk of pathological fractures almost twice. The aim of our research was to assess bone metabolism, nanocomposite structure of the tibia under conditions of ovariectomy and zoledronic acid treatment. Methods X-ray diffraction has been performed for nanostructure analysis of mineral crystallites and crystal lattice of hydroxyapatite in the tibia samples of ovariectomized rats with additional application of bisphosphonate zoledronic acid (0.025 mg/kg). Markers of remodeling – osteocalcin, alkaline phosphatase, tartrate resistant acid phosphatase 5b – were determined. Quantitative amount of calcium in the bones was detected by atomic absorption method. Results Zoledronic acid prevented loss of mineral mass after ovariectomy. Rats after ovariectomy, treated with zoledronic acid, showed statistically higher (р<0.05) values of crystalline phase and calcium content compared with the SHAM-surgery and ovariectomy groups (р<0.05). Zoledronic acid inhibited bone remodeling, which is proved by tartrate resistant acid phosphatase 5b reduction and inhibition of osteoclasts during the experiment. Conclusions These results enable to suggest that zoledronic acid can improve mineral mass of the bone during menopause in individuals of different age groups.

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