Chronic pain, resulting from nerve compression, is a common clinical presentation. One means of conservative treatment is low-level laser therapy, although controversial. The aim of this study was to evaluate the effects of two doses of low-level laser, at 830 nm, on pain reduction in animals subjected to sciatica. Eighteen rats were used, divided into three groups: GS (n=6), sciatica and simulated treatment; G4J (n=6), sciatica and treatment with 4 J/cm 2 ; and G8J (n=6), sciatica and irradiation with 8 J/cm 2 . The right sciatic nerve was exposed and compressed using catgut thread. Five days of treatment were started on the third postoperative day. Pain was assessed by means of the paw elevation time during gait: before sciatica, before and after the first and second therapies, and the end of the fifth therapy. Low-level laser was effective in reducing the painful condition. Key words: pain measurement, sciatica, low level laser therapy.Laser de baixa potência, 830 nm, na redução da dor em ratos submetidos à modelo experimental de ciatalgia RESUMO A dor crônica, resultante de compressão nervosa, é uma apresentação clínica frequente. Um dos meios de tratamento conservador, é o laser de baixa potência, apesar de controvérsias. O objetivo do estudo foi avaliar os efeitos de duas doses de laser de baixa potência, 830 nm, na redução da dor em animais submetidos à ciatalgia. Foram utilizados 18 ratos, divididos em 3 grupos: GS (n=6) ciatalgia e simulado o tratamento; G4J (n=6) ciatalgia e tratado com 4 J/cm 2 , G8J (n=6) ciatalgia e irradiado com 8 J/cm 2 . O nervo isquiático direito foi exposto e realizada a compressão com fio catgut. No 3° dia pós-operatório, iniciou-se o tratamento, durante 5 dias. Verificou-se a dor, por meio do tempo de elevação da pata, na marcha: anterior à ciatalgia, pré e pós 1ª e 2ª terapias, e ao final da 5ª terapia. O laser de baixa potência foi eficaz na redução do quadro álgico. Palavras-chave: medição da dor, ciática, terapia a laser de baixa intensidade.

Objective: To evaluate the efficacy of physical exercise (swimming and jumping), with and without overload, working in reducing the pain of rats undergone to an experimental model of sciatica. Methods: 24 rats were divided into four groups: Placebo (PG), Swimming Group (SG) Swimming 10% Group (SG10) and Jump Group (JG). All groups were submitted to the experimental sciatica model and assessed for pain post-exercise for the Functional Disability Test and the Von Frey filament. Results: In comparison within groups there were significant differences in the moments after injury with the pre-injury, for both assessment instruments. With Von Frey filament was observed a significant difference in group GN10 and GS in the final moments of evaluation. In comparisons between groups were not statistically significant differences obtained with any assessment instrument. Conclusion: Treatment with physical exercise was not effective in reducing pain in rats subjected to experimental sciatica model.

This study aimed at evaluating and comparing the effects of low-level laser therapy (LLLT) and a forced swimming training in a joint nociception model on Wistar rats, in order to functionally register pain by observation of paw elevation time (PET) during gait on a metal cylinder. Thirty-two Wistar rats were divided into four groups: CG -untreated animals submitted to nociception induction on right knee; LG -nociception and treated with 670 nm and 8 J/cm2 LLLT; SG -nociception and swimming for 10 minutes in water at 30-32° C; SLG -nociception and treated with swimming and laser. To achieve the nociception, 50 μL of 5% formalin were injected in the medial tibiofemoral space of each animal. Pain was assessed according to a functional incapacity test, which registered paw elevation time (PET) as well as their gait for one minute on a metallic cylinder. The evaluations occurred before nociception induction (EV1), after 15 minutes (EV2) and after 30 minutes (EV3) of it, with treatment protocols being administered after EV2. The analyses showed that LLLT was the only group to present the restoration values in the EV3 when compared to EV1. SG was the only one which did not show any reduction when compared to EV2 and EV3. Hence, it can be inferred that, by functional evaluation, LLLT had some analgesic effects, while the swimming treatment produced pain increase, which was partially reversed by the use of LLLT.

O objetivo deste estudo foi analisar a influência da crioterapia na dor e edema advindos de sinovite induzida em ratos. Foram utilizados 12 ratos, distribuídos em dois grupos: Controle (GC) - submetido à indução de sinovite no joelho direito, e não tratado; e Tratamento (GT) - submetido à sinovite no joelho direito, e tratado com crioterapia. Para induzir a lesão, foi injetado no espaço tíbio-femoral formalina 5%. Para avaliação da dor foi utilizado o teste de incapacidade funcional, que avaliou a dor durante a marcha do animal (tempo de elevação da pata - TEP); e para quantificar o edema foi utilizado um paquímetro metálico, na região da interlinha do joelho. As avaliações ocorreram antes da injeção de formalina (AV1), 1 (AV2) e 2 horas (AV3) após. Após 10 minutos da lesão, o membro posterior direito foi submerso em água com gelo, à 5ºC por 20 minutos. A avaliação do TEP mostrou aumento de 194,03% (AV2) e 169,26% (AV3) para GC; e 134,25% (AV2) e 103,13% (AV3) para GT, com relação à AV1. Na comparação entre os grupos, em AV3, houve diminuição significativa para GT. A avaliação do edema mostrou aumento do diâmetro, para GC de 39,15% (AV2) e 42,39% (AV3); e 27,91% (AV2) e 14,50% (AV3) para GT, tendo como referência AV1; sendo que apenas GT apresentou diminuição significativa entre AV2 e AV3. Conclui-se que os efeitos em curto prazo, da crioterapia, foram significativos para reduzir a dor e edema, em ratos submetidos à indução de sinovite.

RESUMO | No tratamento de lesões tendíneas, o uso do ultrassom surge como possibilidade terapêutica, apesar de lacunas sobre seus efeitos clínicos. O objetivo foi avaliar dois protocolos de ultrassom terapêutico sobre dor e edema após trauma tendíneo. Vinte e um ratos Wistar foram submetidos a trauma no tendão calcâneo e divididos em três grupos: sham (GS); ultrassom contínuo (GUC); e ultrassom pulsado (GUP). O trauma ocorreu sobre a face lateral do tendão calcâneo direito, com energia de 0,40 J. A dor foi avaliada pelo teste de incapacidade funcional e o edema, pelo diâmetro laterolateral. Foram realizadas avaliações previamente à lesão; após 1 hora da indução da lesão; após o 1º tratamento; 2, 8 e 24 horas após lesão; e após o 5º dia. O tratamento ocorreu em 5 dias, com transdutor de 1 MHz, durante 3 minutos, sobre o local do trauma, com dose de 0,4 W/cm 2 SATA. Os resultados da incapacidade funcional para GS mostraram aumento da nocicepção. Para GUC houve aumento ao comparar a avaliação 1 (AV1) com as avaliações 2 (AV2), 3 (AV3) e 4 (AV4); ao comparar AV2 com as avaliações 5 (AV5) e 6 (AV6) houve diminuição de valores. Para GUP houve aumento ao comparar AV1 com AV2 e AV3, mas ao comparar AV2 com as seguintes, houve diminuição significativa a partir de AV4. Para o edema, os grupos tratados produziram aumento inicial, com redução nas últimas avaliações. O ultrassom terapêutico produziu diminuição de dor e edema, mais precocemente para a forma pulsada.Descritores | tendão do calcâneo; ultrassom; dor; regeneração.ABSTRACT | In tendon injuries treatment, the use of ultrasound appears as a therapeutic option, despite the lack of their clinical effects. The aim was to evaluate two therapeutic ultrasound protocols, continuous or pulsed, on the pain and swelling after tendinous trauma. Twenty-one Wistar rats were subjected to traumatic injury in the tendon and divided in three groups: sham (GS), continuous ultrasound (GUC), and pulsed ultrasound (GUP). The injury occurred on right Achilles tendon lateral aspect, with energy of 0.40 J. The pain was assessed by the functional disability test and edema by latero-lateral diameter. The evaluations were performed before the injury; after 1 hour of the lesion induction; after the 1st treatment; 2, 8 and 24 hours after injury; and after the 5th day. The treatment was made for 5 consecutive days, with transductor of 1 MHz, for 3 minutes on the trauma site, with a dose of 0.4 W/cm 2 SATA. The results of functional disability for GS showed increased nociception. For GUC, there was increased when comparing evaluation 1 (EV1) with evaluations 2 (EV2), 3 (EV3) and 4 (EV4); comparing EV2 to evaluations 5 (AV5) and 6 (AV6), there was decreased values. To GUP there was increased when comparing EV1 with EV2 and EV3, but when comparing EV2 with the following, there was a significant decrease starting from EV4. Edema, treatment groups produced an initial increase with a reduction in recent evaluations. The therapeutic ultrasound produced pain and edema reduction in rats with tendon traum...

Introduction:The protective effect of exercise on individuals with peripheral neuropathy is controversial. Objective: To assess the infl uence of physical training of moderate and progressive intensity on nociception of rats in an experimental sciatica model. Materials and Methods: The study assessed 18 rats divided into the following three groups: control group (CG); low-intensity swimming group (LISG); progressive-time swimming group (PTSG). To meet the physical training protocol, the animals were placed in a water tank for six weeks, three alternate days per week. In LISG group, the animals swam ten minutes per session, and, in PTSG group, the animals began swimming for ten minutes, and had a ten-minute increase per week. In CG group, the animals swam less than one minute per day, only to get used to the water environment. After fi nishing the swimming training, the experimental sciatica model protocol was started with constrictive ligature of the sciatic nerve with chromic catgut. Nociception was assessed using the functional disability test, which measures, in a one-minute interval, the time during which the animal holds its hind paw (THHP) in a guarded position. Assessments were performed preoperatively, and on the third, sixth, and tenth post-operative (PO) days. Results: All groups showed a signifi cant increase in THHP on third, sixth, and tenth PO days, as compared to preoperative values. In CG, no signifi cant change was observed in PO assessments, unlike what happened in LISG and PTSG groups. Conclusion: Exercise produced greater hyperalgesia.

INTRODUÇÃO: Ciatalgia origina-se da compressão do nervo isquiático e implica em dor, parestesia, diminuição da força muscular e hipotrofia. O exercício físico é reconhecido na prevenção e reabilitação de lesões, porém quando em sobrecargas pode aumentar o risco de lesões e consequente déficit funcional. OBJETIVO: Avaliar efeitos de treinamento aeróbico prévio a modelo experimental de ciatalgia em relação a parâmetros morfométricos dos músculos sóleos de ratos. MATERIAIS E MÉTODOS: 18 ratos divididos em três grupos: simulacro (mergulho, 30 segundos); exercício regular (natação, dez minutos diários); e treinamento aeróbico progressivo (natação em tempos progressivos de dez a 60 minutos diários). Ao final de seis semanas de exercício, os ratos foram submetidos ao modelo experimental da ciatalgia. No terceiro dia após a lesão, foram eutanasiados e tiveram seus músculos sóleos dissecados, pesados e preparados para análise histológica. Variáveis analisadas: peso muscular, área de secção transversa e diâmetro médio das fibras musculares. RESULTADOS: Observou-se diferença estatisticamente significativa para todos os grupos quando se comparou músculo controle e aquele submetido à lesão isquiática. A análise intergrupos não apresentou diferença estatisticamente significativa para nenhuma das variáveis analisadas. CONCLUSÃO: Tanto o exercício físico regular quanto o treinamento aeróbico não produziram efeitos preventivos ou agravantes às consequências musculares da inatividade funcional após ciatalgia.

The muscle tissue is endowed with plasticity that adapts to different stimuli. Immobilization causes damage to the musculature including atrophy, loss of muscle strength and extensibility. The stretching and ultrasound treatment modalities are used to speed up muscle repair process as they can increase protein synthesis and improve extensibility. Objective: To compare the use of therapeutic thermal and non thermal ultrasound, associated with stretching, in the remobilization of the soleus muscle of rats subjected to position of muscle shortening on aspects histomorphometric longitudinal muscle. Methods: 28 rats were immobilized for 15 days, later released from the apparatus and divided into four groups: group AG only remobilized by stretching for 10 days and the others were subjected to 10 days of therapeutic intervention 1MHz of ultrasound at 1.0W/cm² (GAUS 1.0), 0.5W/cm² (GAUS 0.5), and 0.2 W/cm² (GAUS 0.2), and further stretching to the soleus. At the end of treatment, the animals were sacrificed and their soleus muscles were removed for later histological analysis of longitudinal parameters (count of sarcomeres). Results: At intragroup analysis on the muscle length, only the group GAUS 0.5 did not present significant difference. The count of sarcomeres in the groups GA and GAUS 0.2 was statistically different. The size of the sarcomeres in both groups had no statistically significant difference. In inter-group analysis both groups had no statistically significant difference for any of the variables. Conclusion: The stretching was insufficient to reverse the effects of immobilization. When associated with therapeutic ultrasound, the dose 0.5 W/cm² recovered muscle length significantly, and the doses 1.0 and 0.5 W/cm² contributed to the significant increase of the number of sarcomeres in immobilized muscles.