Acute effects of gastrocnemius muscle stretching after contusion in rats

Abstract

| The aim of this study was to evaluate the acute effects of stretching after gastrocnemius contusion in rats. Thirty-three male Wistar rats were selected (8 weeks, 219±35 g) and divided into 4 groups: Control (CG, n=3) -intact; Lesion (LG, n=10); Stretching (SG, n=10): Lesion and Stretching (LSG, n=10). The right gastrocnemius (RG) was submitted to contusion. Stretching on RG was performed manually, with 4 repetitions of 30 seconds each day, for 5 consecutive days, beginning 72 hour after contusion. One week later, rats were weighed and both paws were removed for investigation of muscle length, serial sarcomere number and sarcomere length. The final body weight increased in all groups. The muscle weight and length, as well as the serial sarcomere number (SSN) of LG, were higher than SG. However, the SSN of LSG was higher than SG. The sarcomere length of SG was the highest among all groups. It was concluded that the contusion and stretching did not affect body weight gain. The stretching induced sarcomerogenesis in injured muscle, but did not modify the healthy muscle.

Effects of GaAs laser and stretching on muscle contusion in rats

“…To our knowledge, only two studies have described the effect of stretching in injured muscle, which showed new myofibrils and also sarcomerogenesis after 14 days of performance of a stretching protocol 16,17 .…”

“…However, it is not yet known exactly how this therapy combination affect muscle repair 4,5,7,17,18 .…”

“…Only limited evidence was found to support the use of laser or stretching 7,17,19 . Thus, this study aimed to investigate the rat's tibialis anterior muscle morphology submitted to contusion and treated with GaAs laser and/or stretching.…”

Effects of Ultrasound and Stretching on Skeletal Muscle Contusion in Rats: Immunohistochemistry Analysis

“…Experimental animal models contribute to understanding the effects of lengthening stimulus, such as stretching, in the cellular mechanisms of skeletal muscle healing after contusion (Hwang et al, 2006;de Macedo et al, 2014de Macedo et al, , 2016. The involvement of desmin and laminin in force transmission has been described in the literature (De Deyne, 2001).…”

“…The involvement of desmin and laminin in force transmission has been described in the literature (De Deyne, 2001). An increase in sarcomerogenesis and an antifibrotic effect after a stretching protocol of injured rat gastrocnemius has been reported (de Macedo et al, 2014(de Macedo et al, , 2016. Although the proteins desmin and laminin involved in the sarcomerogenesis and muscle healing, have not yet been investigated (Yu & Thornell, 2002;Cação-Benedini et al;Gianelo et al, 2016).…”