These findings could possibly differ from the present study due to the remobilization process exposure times that surpassed that of this study and of its immobilization period. Muscle stiffness represents an important property done to be studied, since the reduction of its values indicates that the muscle is stretching more in the presence of a smaller load, which also renders it more susceptible to injuries.5,7 Considering the deformation of structural proteins of the muscle fiber during the mechanical trial, among the structures that are accountable for this tensile resistance behavior, special emphasis should be placed on the extracellular matrix and titin24, a structural protein of sarcomere that assists in the natural passive resistance of the muscle.
These two structures are considered responsible for the viscoelastic resistance of the musculotendinous complex.17 Immobilization reduces the extensibility of sarcomeric proteins (titin) and their isoforms (�� and ��)2, besides promoting modifications in the extracellular matrix.17 However, in this study, the immobilization protocol was probably not sufficient to cause changes in this property both in the adult group and in the older group. Carvalho et al.15 found reduction of stiffness, load and stretching at the maximum limit resulting from immobilization for 14 days. The free remobilization process over a 10-day period was sufficient to restore these values. CONCLUSION It is concluded that immobilization is able to induce alterations in the mechanical properties, reducing the muscle’s ability to bear loads both in adult and in older animals.
Free remobilization did not demonstrate any effects in the short post-immobilization period in either age group, while remobilization by physical exercise presented a tendency for an increase in the LML, which was not sufficient to restore it to normal levels. We can conclude that the age or aging factor can interfere in a negative manner in the recovery response of the muscle tissue with regards to the mechanical property of SML in the post-immobilization period. Acknowledgments We are grateful to CAPES and to the Dean’s Office for Graduate Studies (Pr��-reitoria de P��s-gradu??o) of UNESP for granting a Masters scholarship, to Prof. Dr. Ant?nio Carlos Shimano and Prof.
Rodrigo Okubo, to the technician of the Histology and Histochemistry Laboratory, Sidney Siqueira Leiri?o, and to the coordinators of the Masters course in Physiotherapy of FCT/UNESP. Footnotes All the authors declare that there is no potential conflict of interest referring to this article. Study conducted at the Histology Anacetrapib and Histochemistry Laboratory of the Physiotherapy Department, Faculdade de Ci��ncias e Tecnologia �C FCT/UNESP, Presidente Prudente.
Childhood cancer is rare and was estimated by the Brazilian National Cancer Institute (INCA), in the biennium 2008/2009, at about 9,890 new cases.