Adaptações biomecânicas do osso cortical de camundongos submetidos à três diferentes modalidades de exercício

Abstract

Objective To compare the adaptive effects of three non-weight bearing exercise on bone mechanical properties. Methods 24 male Balb/c mice (22-25g), were randomly divided into four groups (n=6): sedentary group (S); swimming group (N) which performed sessions five times per week for 60 min progressively; resistance group (R), which performed climbing exercise with progressive load, three times per week; and combined group (C), which performed the same protocols aforementioned being three times a week according to N protocol and two times a week the R protocol during eight weeks. Biomechanical tests, load until failure and stiffness evaluation of shinbone was performed after animals have been sacrificed. Results Stiffness values were statistically higher only in the isolated modalities groups (N and R, 41.68 ± 10.43 and 41.21 ± 11.38 N/mm, respectively) compared with the S group (28.48 ± 7.34 N/mm). However, taking into consideration the final body mass, relative values, there was no difference in the biomechanical tests among the groups. Conclusion Data from the present investigation demonstrated a favorable influence of muscle contraction in lower impact isolated exercise modalities on absolute stiffness values, i.e.groups N and R, whereas the combined group (C) did not present any statistical significant difference compared to sedentary group. Level of Evidence II, Prospective Comparative Study.

Effects of simvastatin associated with exercise on the mechanical resistance of muscle and bone in rats

“…The muscular action in physical exercise promotes a mechanical stimulation to the bones, which, due to their piezoelectric properties, respond positively to this stimulus. 9 In turn, simvastatin did not affect bone stimulation; both groups presented similar BMD and mechanical properties. In the present study, physical exercise, as a strong factor influencing bone tissue, may have suppressed the simvastatin response.…”

<b>Avaliação biomecânica dos ossos III/IV metacarpianos com falhas ósseas induzidas experimentalmente, tratados com mantas ósseas a base de quitosana, hidroxiapatita e colágeno, em ovinos<b>

“…Com o avanço da idade, ocorre o predomínio da atividade osteoclástica aumentando o processo de desmineralização óssea, a qual é atribuída principalmente a degeneração dos constituintes trabeculares da estrutura óssea. Embora haja alguma compreensão acerca das modificações ósseas em função de estímulos mecânicos, ainda não se sabe quais são os níveis e as frequências de estimulação mecânica necessárias para desencadear o processo de controle/regulação da modelagem e remodelagem óssea (HOLANDA, 1999;BARROS, 2008;FRAJACOMO et al, 2013).…”

Terapia por ondas de choque eletrohidráulicas aumenta a atividade de ERK-1/2 e Akt em tíbias íntegras de ratos por 21 dias após estímulo inicial

“…Sabe-se que o estímulo mecânico gerado pela força gravitacional e atividade física são essenciais para manutenção da homeostase (formação e reabsorção) óssea (Duncan e Turner, 1995, Frajacomo et al, 2013. Neste sentido a TOC tem sido utilizada nos últimos anos como método alternativo de estímulo mecânico inclusive para estimular a consolidação óssea em pacientes com pseudoartrose (Schaden et al, 2011, Xu et al, 2009.…”