Prevention of low back and pelvic girdle pain during pregnancy: a systematic review and meta-analysis of randomised controlled trials with GRADE recommendations.

BACKGROUND: Low back (LBP) and pelvic girdle pain (PGP) during pregnancy are related to high direct and indirect costs. It is important to clarify evidence regarding interventions to manage and prevent these conditions. OBJECTIVE: Investigate the efficacy and acceptability of the interventions to prevent LBP and PGP during pregnancy. DATA SOURCES: Searches were conducted up to January 6th, 2021 in the MEDLINE, PEDro, Cochrane Library, SPORTDiscus, CINAHL, AMED, Embase and PsycInfo databases STUDY ELIGIBILITY CRITERIA: (1) Pregnant women without LBP and/or PGP; (2) any prevention strategy on incidence of LBP and PGP and sick leave; (3) comparison to control; (4) quasi and randomised controlled trial. STUDY APPRAISAL AND SYNTHESIS METHODS: Two reviewers performed screening, data extraction and methodological quality assessments. Meta-analysis was performed and Relative Risks (RRs) and 95% confidence intervals (CIs) were reported. RESULTS: Six randomised controlled trials involving 2231 participants were included in the review. Evidence of moderate quality was found that "stand-alone" exercise is acceptable to pregnant women with lumbopelvic pain (LBPP) (RR 0.60 [95%CI 0.42-0.84]) and prevents episodes of LBP (RR 0.92 [95%CI 0.85-0.99]) in the long-term. Moderate to very-low quality evidence was found detailing the lack of efficacy of other interventions in the prevention of these problems in the short and long-term. LIMITATIONS: Small number of trials included. CONCLUSIONS: Efficacy of prevention strategies for episodes of LBPP and the use of sick leave during pregnancy is not supported by evidence of high quality. Current evidence suggests that exercise is acceptable and promising for the prevention of LBP in the long-term. However, further high-quality trials with larger samples are needed. CONTRIBUTION ON PAPER.

Acute toxicity and regenerative dose finding of an extract of Miconia ferruginata DC. in a mouse model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a severe disease with no cure caused by a genetic abnormality, promoting progressive muscle degeneration. Corticosteroids are used drugs in treatment associated with adverse effects. The extract of Miconia ferruginata (Melastomataceae) (MF) has demonstrated potent antioxidant and anti-inflammatory potential in vitro. This study used a DMD model (mdx) to determine the toxic dose of this plant and found a possible non-toxic dose with therapeutic effects. The mdx groups received an intraperitoneal injection of 0 (control group), 50, 100, 200, 300, and 2000 mg kg-1 of the aqueous leaf extract following a single-dose acute toxicity protocol and were observed for 14 days. The range of toxicity of the extract and LD50 were determined. Histopathological analysis, the quantification of fibrosis, and immunohistochemical analysis of the tissues were performed. The results demonstrated that 2000 mg kg-1 was highly toxic, inducing histopathological changes in the tissues evaluated, with 100% mortality in 48 hours. The other doses caused no behavioral changes or signs of toxicity. The MF extract led reduction in histopathological changes, fibrosis, and inflammation, a reduction in HSP70 and an increase in MCL-1 proteins. Doses of 50-200 mg kg-1 demonstrated regenerative tissue and anti-inflammatory potential.

Insulin resistance is improved in high-fat fed mice by photobiomodulation therapy at 630 nm.

Photobiomodulation therapy (PBMT) in the infrared spectrum exerts positive effects on glucose metabolism, but the use of PBMT at the red spectrum has not been assessed. Male Swiss albino mice were divided into low-fat control and high-fat diet (HFD) for 12 weeks and were treated with red (630 nm) PBMT or no treatment (Sham) during weeks 9 to 12. PBMT was delivered at 31.19 J/cm2 , 60 J total dose per day for 20 days. In HFD-fed mice, PBMT improved glucose tolerance, insulin resistance and fasting hyperinsulinemia. PBMT also reduced adiposity and inflammatory infiltrate in adipose tissue. Phosphorylation of Akt in epididymal adipose tissue and rectus femoralis muscle was improved by PBMT. In epididymal fat PBMT reversed the reduced phosphorylation of AS160 and the reduced Glut4 content. In addition, PBMT reversed the alterations caused by HFD in rectus femoralis muscle on proteins involved in mitochondrial dynamics and ß-oxidation. In conclusion, PBMT at red spectrum improved insulin resistance and glucose metabolism in HFD-fed mice.

Effects of two intensities of treadmill exercise on neuromuscular recovery after median nerve crush injury in Wistar rats.

Considering the potential action of exercise on neuroplasticity and the need to adapt protocols to enhance functional recovery after nerve injury, this study evaluated the effects of two intensities of treadmill exercise on nervous and muscular tissues and functional recovery after nerve crush injury. Wistar rats were distributed into sedentary group (SED), and 10 m/min (EG10) and 17 m/min (EG17) exercise groups. The exercise started one week after the injury. Ten daily sessions were performed with a 2-day interval after the fifth day. The flexor digitorum muscle and two segments of the median nerve were analysed histomorphometrically by light microscopy and computer analysis. Function was evaluated by grasping test, in 3 moments. Approval number: 016/2013. In the proximal segments of the median nerve, the diameter of myelinated fibres and axon, the myelin sheath thickness and the ratio of axon diameter to fibre diameter (g ratio) were significantly larger (P<0.05) in the EG10. The number of myelinated fibres was lesser in the EG17 than the other groups (P<0.05). No difference in the number of myelinated fibres among groups was observed in the distal segments, but the SED presented significantly larger axon and fibre diameters than those that performed exercise. The EG10 presented greater area and diameter of muscle fibres (P<0.05) and functional improvement observed on the 21st day after injury (P<0.05) compared with the EG17 and SED. Continuous exercise at 10 m/min accentuates nerve regeneration, accelerating functional recovery and preventing muscle atrophy.

Low-intensity training provokes adaptive extracellular matrix turnover of a muscular dystrophy model.

Recommendations of therapeutic exercise in Duchenne muscular dystrophy are still controversial. The hypothesis that a low-intensity training (LIT) protocol leads to muscle adaptations on mdx mice model was tested. Dystrophic male mice with 8 weeks old were separated in exercised (mdxE, n= 8) and sedentary (mdxC, n= 8) groups. Wild-type mice were used as control (WT, n= 8) group. Exercised group underwent a LIT protocol (9 m/min, 30 min, 3 days/wk, 60 days) on a horizontal treadmill. At day 60 all animals were analyzed regarding parameters of markers of muscle lesion and extracellular matrix turnover of muscle tissue by collagens fibers on tibial anterior muscle. Histomorphometry attested that centrally located nuclei fibers and the coefficient of variance of minimal Feret's diameter was similar in mdxE and mdxC groups (P= 1.000) and both groups presented higher mean values than WT group (P< 0.001). Fraction area of collagen fibers of mdxE group was lower than mdxC group (P= 0,027) and similar to WT group (P= 0,751). Intramuscular area of Col3 of the mdxE group was higher than mdxC and WT groups (P<0.001). Intramuscular area of Col1 on the mdxE group was similar to the mdxC group (P= 1.000) and both groups were higher than WT group (P< 0.001). LIT protocol had not influenced muscle injuries resulting from the dystrophin-deficiency membrane fragility. Although, LIT had provoked adaptations on extracellular matrix bringing higher elastic feature to dystrophic muscle tissue.