Effect of one stretch a week applied to the immobilized soleus muscle on rat muscle fiber morphology

Abstract

We determined the effect of stretching applied once a week to the soleus muscle immobilized in the shortened position on muscle fiber morphology. Twenty-six male Wistar rats weighing 269 ± 26 g were divided into three groups. Group I, the left soleus was immobilized in the shortened position for 3 weeks; group II, the soleus was immobilized in the shortened position and stretched once a week for 3 weeks; group III, the soleus was submitted only to stretching once a week for 3 weeks. The medial part of the soleus muscle was frozen for histology and muscle fiber area evaluation and the lateral part was used for the determination of number and length of serial sarcomeres. Soleus muscle submitted only to immobilization showed a reduction in weight (44 ± 6%, P = 0.002), in serial sarcomere number (23 ± 15%) and in cross-sectional area of the fibers (37 ± 31%, P < 0.001) compared to the contralateral muscles. The muscle that was immobilized and stretched showed less muscle fiber atrophy than the muscles only immobilized (P < 0.05). Surprisingly, in the muscles submitted only to stretching, fiber area was decreased compared to the contralateral muscle (2548 ± 659 vs 2961 ± 806 µm 2 , respectively, P < 0.05). In conclusion, stretching applied once a week for 40 min to the soleus muscle immobilized in the shortened position was not sufficient to prevent the reduction of muscle weight and of serial sarcomere number, but provided significant protection against muscle fiber atrophy. In contrast, stretching normal muscles once a week caused a reduction in muscle fiber area.

Effects of GaAs laser and stretching on muscle contusion in rats

“…Stretching skeletal muscle is very important not only to increase the joint range of motion, but also to prevent and treat injuries, thus being a tool of therapeutic intervention for physical rehabilitation and sports medicine 12 . Static stretch of skeletal muscle cells in vitro or in vivo results in well-defined changes in cellular growth, morphology, and metabolism 13 , which includes muscle hypertrophy, prevents muscle atrophy and implicates in the modulation of muscle fiber behavior 14 .…”

Efeito agudo da técnica de reeducação postural global na postura de mulheres com encurtamento da cadeia muscular anterior

“…Já a distância fio de prumo-trago diminuiu 2,1 ± 0,2 cm (6,2 ± 1 cm vs 8,3 ± 2 cm, p = 0,005), e a distância fio de prumo-acrômio diminuiu 2,2 ± 0,3 cm (3,3 ± 1 cm vs 5,5 ± 1 cm p = 0,005), após a técnica de RPG. A diferença relativa entre o pré e o pós para ambos os grupos, está descrita na Tabela 1. sabido que esse fenômeno pode ocorrer efetivamente durante o alongamento crônico, isto é, realizado ao longo de semanas (30)(31)(32). Outra hipótese a ser considerada, é que a simples descompressão das estruturas vertebrais ocorrida pela tração axial foi capaz de modificar a posição da cabeça após a técnica de RPG.…”

Effect of Gonadal Hormones on the Cross‐Sectional Area of Pubococcygeus Muscle Fibers in Male Rat

“…Now we can add that these hormones can also avoid the reduction of the CSA of Pcm fibers after 6 weeks of castration. According to some studies, the CSA of muscle fibers is generally correlated with their activity, which is promoted by the activity of the respective motoneuron (Witzmann et al, 1982;Deschenes et al, 1997;Nnodim, 1999Nnodim, , 2001Brown et al, 2001;Dedkov et al, 2001;Gomes et al, 2004;Dow et al, 2004Dow et al, , 2006. Thus, doses of gonadal hormones that promote an increment in the size of the soma of the levator ani motoneurons are also effective in increasing the CSA of the fibers of this muscle (Jordan et al, 1995).…”