title: Effects of short duration static stretching on the denervated and reinnervated soleus muscle morphology in the rat.
abstract: OBJECTIVE
  To investigate the effect of short duration static stretching of denervated and reinnervated muscle using a histochemical study on the soleus muscle of the rat.
  
  
  METHODS
  Prospective randomized trial.
  
  
  METHODS
  University medical school in Japan.
  
  
  METHODS
  Fifty-four 8-week-old female Wistar rats with a mean weight +/- standard deviation of 185.8+/-9.9g.
  
  
  METHODS
  After a cold injury was applied to the rat right sciatic nerve, the bilateral soleus muscles were maximally stretched in the dorsiflex posture of the ankle joints for 40 minutes a day, 6 times a week (group S). Rats were compared with nonstretched rats (group D) for up to 4 weeks. Main outcome measures Muscle fiber cross-sectional areas, muscle fiber types, and sciatic nerve morphology.
  
  
  RESULTS
  No apparent difference in the morphologic changes of the sciatic nerve was found between groups D and S. The mean fiber size progressively declined to a minimum 2 weeks after the injury and reversed in the following weeks. At weeks 1 and 2, the mean type I fiber size in group S was significantly larger than in group D (P<.05). The number ratio of the type II to total fibers increased until 3 weeks in group D, whereas the ratio in group S was increased at 2 weeks, and successively decreased.
  
  
  CONCLUSIONS
  The mechanical stimuli of static stretching could prevent atrophy of the type I fibers in the denervated muscle and affect the reinnervated muscle fiber-type composition.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005260:Female; D005615:Freezing; D009121:Muscle Denervation; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000294:innervation / Q000473:pathology*; D009133:Muscular Atrophy; D011446:Prospective Studies; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000293:injuries