CHANGES OF THE PENETRATION STRENGTH OF THE LUMBAR VERTEBRAE TRABECULAR BONE OF ATHLETES DURING TRAINING

INTRODUCTION: Great static and dynamic load during athletic trainings with weightlifting exercises influence the skeleton, especially spine, of athletes. Some athletes feel pain in lumbar region during such athletic training. Changes in vertebrae bone tissue are mentioned as one of the reasons for pain (1). The osteopenetromethry method has been used for the evaluation of vertebra trabecular bone during the previous years (2,3). The purpose of this study was to examine the changes of vertebra penetration strength (PS) in lumbar region of athletes during the athletic training with weight-lifting exercises using this method. METHODS:120 athletes (aged 18 to 26) from different sports (Tab.1) were examined. We examined PS of 3 to 5 lumbar vertebrae on the 1st, 7th, 14th, 21st and 28th day of athletic training, according to the method described by Logins (3). RESULTS:The PS of lumbar vertebrae of the athlets on the 1st training day was from 4.2 MPa up to 5.1 MPa. On the 7th day of training the decrease from 17% to 35% of the initial value of PS was denoted. According to the level of PS decrease, we conditionally divided the athlets into two groups. The PS of the first group athlets was decreased for 20% of the initial value. The PS decrease of the second group of athlets exceeded 20% of the initial value (Tab.2) [Tab.2.] On the 14th day of athletic training’s the rehabilitation of the initial level of PS of lumbar vertebrae was denoted for the first group athletes and stayed the same during all the time of intensive load (28 days). For the second group of athletes during the time of intensive load the decrease of PS of lumbar vertebrae was denoted up to 2.7±0.38 MPa on the 28th day of athletic training. CONCLUSIONS: The results of our investigation prove that intensive physical load during athletic training’s with weight-lifting exercise of athletes causes changes to the structural organization of vertebral trabecular bone and bone mineral content. If the load exceeds the functional possibilities of spine, the remarkable changes of the vertebral trabecular bone strength take place in 7th day of training. REFERENCE: 1. Silva MJ.Gibson JA.(1997) Bone 21(2):191-199. 2. Hvid I. (1988) Clin Orthop.227: 210-221. 3. Logins V (1996) Mechanics of Composit.Materials 4:564-573

Skriemelu kaulaudu biomehaniskas ipasibas

The expansion of spine degeneration diseases in industrially developed countries and increase of these diseases among middle aged people prove that new experimental and clinical researches are necessary for solvation of this problem. The effectiveness of treatment and prophylaxis are considerably decreased by late diagnostics of spine degeneration diseases. Knowledge about the changes of mechanical properties of vertebrae during the period of influence of old or under the influence of pathological processes are necessary for the development of early diagnostics. The goal of our work is to denote the acoustic and strength properties and its connectedness of vertebrae bone tissue in order to work out an early diagnostics method - osteopenetrometry - of spine degenerative diseases. Experimental researches for denoting ultrasound velocity, acoustic anizotropy and penetration strength are made with 60 saples of cortical and trabecular vertebrae bone tissue. The changes of penetration strength during the intensive load have been denoted in clinical observations of 120 athletes. The changes of penetration strength of vertebral trabecular tissue and intraosal circulation of blood have been denoted for 700 patients with different stages of degenerative diseases. Experimental researches showed that cortical and trabecular vertebrae bone tissue are characteristic with anizotropy and heterogeneousity of acoustic and strength properties for the age group from 20 to 40. The changes of acoustic, strength properties and acoustic anizotropy have been denoted during the period of becoming old (after 40). Decrease of ultrasound velocity was mostly observed in dorsal region of cortical bone tissue and in front region of trabecular bone tissue. The decrease of acoustic anizotropy has been denoted in front part of vertebrae of cortical and trabecular bone tissue. The high level of correlation of ultrasound velocity and penetration strength of vertebrae bone tissue prove that penetration strength could be used in diagnostics of changes of the strength of vertebrae bone tissue. It was ascertained that early stages of spine degeneration diseases are characteristic with a considerable decrease - about 30% to 50% in comparison with healthy people - of the strength trabecular bone tissue of vertebrae. Parallely with the decrease of penetration strength of trabecular bone of vertebrae, the changes of intraosal blood circulation - increase of intraosal pressure and intraosal venous stases - were denoted. Experimental researches and clinical observations showed that changes of strength of vertebrae bone tissue and intraosal blood circulation are the main factors in pathogenesis of early stages of spinal degenerative diseases. Osteopenetrometry could be used for early diagnostics of spinal degenerative diseases as well as for estimation of effectiveness of treatmentSeparate summary in Latvian, English, Russian, 29 p.Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi