Therapeutic immobilization is a common treatment for the locomotor system; however, it causes loss of muscle due to disuse, leading to protein degradation and generating atrophy of muscle cells, ultimately changing functionality. In this sense, it is important for remobilization to be initiated early and performed with appropriate therapeutic strategies that enable tissue and functional recovery. One method of remobilization is physical exercise, among which whole body vibration (WBV) has been highlighted and mainly applied in people with reduced mobility. However, there are gaps on the morphological effects WBV has on muscle tissue, so in this study we analyzed the histomorphometry of the tibialis anterior muscle (TA) of Wistar rats remobilized using WBV. For the experiment, 32 male Wistar rats were used and divided into four groups (n = 8/group). Groups consisted of: control (CG), immobilized (IG), immobilized and remobilized freely (FG), and immobilized and remobilized with WBV (WG). After the experimental period, the TA was collected and processed for analysis in light microscopy. When compared to the control group, significant morphological changes were observed, which characterize muscle atrophy and reduction of all histomorphometric parameters of the TA of the immobilized animals. Remobilized animals showed improvement in all parameters, and the WBV was not different from the free remobilization, except for the reduction of central nuclei, which can be related to acceleration of the process of tissue regeneration. Thus, we can conclude that the WBV can have an impact on the acceleration of the muscle regenerative process, and may be beneficial in people with reduced mobility.

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Aim: To evaluate the effects of whole-body vibration in the sciatic nerve of oophorectomized Wistar rats, on nociceptive and morphological parameters, such as fiber, axon, and myelin sheath diameters, G ratio, number of nerve fiber and nuclei of Schwann cells, and percentage of connective tissue. Method: Sixty-four rats were used in the groups sham-operate and oophorectomy (n = 32/group); after surgical procedures, each group was subdivided into four: euthanized in the 12 th week, untreated and treated for four weeks; and euthanized in the 16 th week, untreated and treated for eight weeks. The treatment with vibration was performed with a 60 Hz frequencies, for 10 minutes, three days a week, with duration of 4 or 8 weeks. Nociception was evaluated later, in the right paw, by means of a digital analgesimeter, prior to surgery, at the beginning and at the end of the protocol. After the trial period, the sciatic nerve was dissected for examination of the general morphology of the tissue and morphometric analysis; later, the animals were euthanized. Results: Regarding nociception and the morphometry of the sciatic nerve, independent of oophorectomy and treatment time, there was no statistically significant difference within and between groups. Also, the general morphology of the tissue in all groups had characteristics that were preserved. Conclusion: The mechanical vibration did not alter the nociceptive threshold and the morphological aspects of nerve fibers in oophorectomized Wistar rats.

Objective  To evaluate the neuromuscular junctions (NMJs) and the type of muscle fibers of the soleus muscle of oophorectomized Wistar rats submitted to a mechanical vibration protocol. Methods  A total of 36 randomized rats were used in the pseudo-oophorectomy without and with treatment and oophorectomy without and with treatment groups. The treatment was performed with a vibratory platform, frequency of 60 Hz and duration of 10 minutes, 3 times a week, for 4 weeks. At the end of the intervention period, the animals were euthanized and the soleus muscles were collected and processed for analysis of the NMJs and fiber type. The data were analyzed for normality by the Shapiro-Wilk test and analysis of the 3-way variance using the post-hoc Tukey test, when necessary, and a significance level of 5% was adopted. Results  In the analysis of the NMJs, the oophorectomy group presented a smaller area than the pseudo-oophorectomy group, but the oophorectomy with treatment group was equal to the pseudo-oophorectomy with treatment group. For the larger diameter of the joints, the oophorectomy group was also different from the others; however, the oophorectomy and treatment animals were larger than those of the pseudo-oophorectomy and treatment group. There was no distinction of the types of fibers, with the muscle presenting fibers of the oxidative type. Conclusion  Hormonal deprivation reduced the area and diameter of the NMJs, with reversion of this process in the groups that underwent vibratory platform treatment for 4 weeks, and both surgery and treatment did not influence the type of soleus muscle fiber, composed of oxidative fibers.

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BACKGROUND AND OBJECTIVES:The vibrating platform can attenuate the deleterious effects of immobilization related to muscle atrophy. However, there is still a gap regarding the effect of this modality on hyperalgesia related to immobilization. The objective of this study was to analyze the effect of remobilization with whole-body vibration on the nociception of Wistar rats. METHODS: Sixteen rats were randomly distributed into two groups: the FRG group -immobilization and free remobilization and the VPRG -immobilization and remobilization with the vibrating platform. For remobilization with the vibrating platform, the frequency of 60Hz for 10 minutes, five days a week for two weeks was used. The nociception was evaluated on the right paw by a digital analgesiometer, before and at the end of the immobilization, and after two weeks of remobilization. RESULTS: There were differences between evaluations but not between groups, indicating that immobilization reduced the nociceptive threshold and free remobilization, and the remobilization associated with vibration improved the nociceptive threshold compared to the post-immobilization moment. However, they were not able to return to the initial parameters. CONCLUSION: Joint immobilization reduced the nociceptive threshold; however, two weeks of whole-body vibration remobilization were not able to revert the threshold in the immobilized groups.

Introduction and aim. The knee is one of the joints where immobilization is most used, however, it can cause morphological changes in the joint tissues and is a challenge to be overcome during rehabilitation. Whole-body vibration (WBV) is capable of generating repetitive oscillatory movements, which cause mechanical stimuli that interfere with tissue plasticity. The aim of this study was to analyze the knee morphology of Wistar rats submitted to remobilization with WBV. Material and methods. 32 male rats were used, divided into four groups (n=8): Control Group (G1), Immobilization Group (G2), Immobilized Group and Free Remobilization (G3), Remobilized Group with WBV (G4). For immobilization, a plastered apparatus was used for 15 days. G3 and G4 carried out free remobilization or with WBV, respectively, for 2 weeks. The knee joints were processed for light microscopy. Results. The WBV led to a reduction in the inflammatory infiltrate in the articular cavity and greater presence of adipocytes in the subintima of the synovial membrane. Conclusion. Remobilization with WBV induced a better tissue response in the synovial membrane when compared to free remobilization.

GR, Lucinéia de Fátima Chasko Ribeiro. Immobilization and experimental periodontitis in tibial anterior muscle of wistar rats. Abstract Introduction and objective. Periodontal disease (PD) is a chronic inflammation, locally attacking the supporting tissues of the tooth; this inflammatory condition can affect other systems, such as muscle tissue, which is also susceptible to several types of injury such as caused by immobilization. The aim of this study was to assess whether periodontal disease potentiates the deleterious effects of immobilization of the anterior tibial muscle of Wistar rats. Materials and method. Twenty animals were randomly assigned to four groups (n=5): Control Group (CG), Periodontal Disease Group (PDG), Immobilized Group (IG) and PD plus Immobilization Group (PDIG). PD was induced on day 1 of the experiment by placing a cotton thread in the first lower molars for 30 days, favouring the accumulation of bacterial plaque. On day 15, the right pelvic limb was immobilized for 15 days. On day 30, the animals were euthanized and the tibialis anterior muscle was collected with further processing for histomorphometric analysis. Results. In the cross-sectional area there were PDIG differences between CG and PDG. For the larger diameter, CG was higher than IG and PDIG. For the smaller diameter, PDIG presented a lower value among all the groups in the same way with the number of nuclei. For connective tissue, there was an increase in the amount between the CG and PDIG, IG and PDIG groups, as well as PDG and PDIG. Conclusion. Periodontal disease potentiated the deleterious effects of immobilization on the anterior tibialis muscle.