Photobiomodulation and physical exercise on strength, balance and functionality of elderly women / Fotobiomodulação e exercício fisíco na força, equilíbrio e funcionalidade de mulheres idosas / Fotobiomodulación y ejercicio físico en la fuerza, equilibrio y funcionalidad de mujeres mayores

Abstract Introduction: Aging is associated with structural changes in muscle tissue, which leads to the loss of functional independence. The preservation of the muscle strength through strength training, and recently, low-level laser therapy (LLLT), has high clinical significance. Objective: to investigate the effects of photobiomodulation (PBM - 808 nm, 100 mW, 35.7 W/cm2 and 7 J) associated with a strength training program on quadriceps muscle strength, balance and functional capacity in elderly women. Methods: Thirty-five healthy women between 60 to 70 years old were divided into two groups: Placebo Group (n = 13) and Active Group (n = 14). The exercise protocol consisted of knee flexion-extension exercise followed by application of PBM placebo or active, twice a week for 8 consecutive weeks. Results: showed a significant increase in 6MWT (p = 0.001), SPPB (p = 0.006) and 1-MR (p = 0.001) in both groups. The strength training program associated with PBM active improved a significant increase, relative to baseline, to the right medial/lateral stability index (p = 0.007) and decrease in the Fall Risk Test (p = 0.005). Conclusion: the strength training produced a significant increase of muscle strength and functionality and when combined with the PMB it was significant in the improvement of postural stability and decrease of fall risk.

Resumo Introdução: O envelhecimento está associado a mudanças estruturais no tecido muscular, que levam à perda da independência funcional. A preservação da força muscular através do treinamento de força e, recentemente, da terapia laser de baixa intensidade (TLBI), têm alta significância clínica. Objetivo: investigar os efeitos da fotobiomodulação (808 nm, 100 mW, 35,7 W/cm2 e 7 J) associada a um programa de força muscular direcionado à força do músculo do quadríceps, equilíbrio e capacidade funcional de mulheres idosas. Métodos: 35 mulheres saudáveis entre 60 e 70 anos de idade foram divididas em dois grupos: Grupo Placebo (n = 13) e Grupo Ativo (n = 14). O protocolo de exercício consistiu no exercício de flexão e extensão de joelhos seguido da aplicação da fotobiomodulação placebo ou ativa, 2 vezes por semana por 8 semanas consecutivas. Resultados: mostraram um aumento significativo no TC6 (p = 0,001), SPPB (p = 0,006) e 1-RM (p = 0,001) em ambos os grupos. O programa de treinamento de força associado a fotobiomodulação ativa promoveu um significativo aumento relativo à avaliação inicial, no índice de estabilidade medial/lateral direito (p = 0,007) e diminuição no Teste de Risco de Queda (p = 0,005). Conclusão: o treinamento de força produziu um significativo aumento da força muscular e da funcionalidade e, quando combinado com a fotobiomodulação, foi significativo em promover estabilidade postural e diminuição do risco de queda.

Resumen Introducción: Envejecimiento está asociado a cambios estructurales en el tejido muscular, que llevan a la perdida de la independencia funcional. La preservación de la fuerza muscular a través del entrenamiento de fuerza, y recientemente, la terapia láser de baja intensidad (TLBI), tiene alta significancia clínica. Objetivo: investigar los efectos de la fotobiomodulación (808nm, 100mW, 35,7 W/cm2 y 7J) asociado a un programa de fuerza muscular del músculo cuádriceps, equilibrio y capacidad funcional de mujeres mayores. Métodos: 35 mujeres sanas entre 60 y 70 años de edad fueran repartidas en dos grupos: Grupo Ejercicio y Láser Placebo (n = 13) y Grupo Ejercicio y Láser Activo (n = 14). El protocolo de ejercicio consistió en flexión extensión de rodillas seguido de la aplicación de la fotobiomodulación placebo o activa, 2 veces en la semana durante 8 semanas consecutivas. Resultados: mostraron un aumento significativo en el TC6 (p = 0,001), SPPB (p = 0,006) y 1-RM (p = 0,001) en los dos grupos. El programa de entrenamiento de fuerza asociado a la fotobiomodulación activa promovió un aumento significativo, relativo a la evaluación inicial, en el índice de estabilidad medial / lateral derecho (p = 0,007) y disminución en la prueba de riesgo de caída (p = 0,005). Conclusión: El entrenamiento de fuerza produjo un aumento significativo de la fuerza muscular y funcionalidad, incluso cuando se combinó con la fotobiomodulación fue significativo en promover estabilidad postural y disminución del riesgo de caída.

The effects of low level laser therapy on injured skeletal muscle

The main purpose of the present study was to investigate the effects of low-level laser therapy (LLLT) used in two different fluencies on injured skeletal muscle after cryolesion by means of histopathological analysis and immunohistochemistry for COX-2. A total of sixty male Wistar rats were randomly distributed into three groups: injured animals without any treatment; 808 nm laser treated group, at 10 J/cm² and 808 nm laser treated group, at 50 J/cm². Each group was divided into two different subgroups (n=10) on days 6 and 13 post-injury. The results showed that the animals irradiated with laser at 10 J/cm² or 50 J/cm² presented the areas with cell infiltrate and pointed out to minor and mild areas with destroyed zones compared with the control group. Also, a COX-2 downregulation was noticed in the groups exposed to laser at two fluences evaluated in this study. Significant statistically differences (p<0.05) were noticed to collagen deposition in the laser treated animals, with the fluence of 50 J/cm² when compared to the other groups on day 13 post-surgery. Taken together, these results suggested that laser therapy could have positive effects on muscle repair in the rats after cryolesion.

Effects of low-level laser therapy on biceps braquialis muscle fatigue in young women.

OBJECTIVE: This study aims to investigate the effects of low-level laser therapy (LLLT) on biceps brachi muscular fatigue in 20 young females. BACKGROUND DATA: Exhausting physical activity leads to muscular fatigue, which could decrease muscular strength, and may cause impairment in motor control and muscle pain. Several biochemical and biophysical resources have been studied in an attempt to accelerate the recovery of muscle fatigue. Among these, LLLT is emphasized. METHODS: Twenty subjects were randomized in one laser group and one placebo group in two sessions of a crossover design experimental procedure; the second session taking place within 7 days of the first. In the first session, subjects underwent a collection of surface electromyographic (SEMG) data of the biceps brachii muscle, followed by active or placebo LLLT at the same muscle, followed then by another EMG sample of biceps brachii. Blood samples were collected five times during the experimental procedure. Second session procedures were identical to the first, with exception of LLLT, which was the opposite of the first session. The fatigue protocol consisted of 60 sec of elbow flexion-extension movement performed with 75% of one maximum repetition. Blood lactate, EMG fatigue, and the number of elbow flexion-extension repetitions during the fatigue protocol were used to evaluate the effects of laser therapy (808 nm wavelength, 100 mW output power, power density of 35.7 W/cm(2), 70 sec each point and 7 J/point on eight points). RESULTS: No statistical differences were found for eletromyographic fatigue and blood lactate values between groups. Mean numbers of elbow flexion-extension repetitions were 22.6 ± 7.58 after placebo, and 25.1 ± 9.89 after active LLLT group, but these differences were not statistically significant (p=0.342). CONCLUSIONS: LLLT had limited effects on delaying muscle fatigue in a young female sample, although a tendency was observed in the active laser group toward showing lower electromyography fatigue of biceps brachii muscle. No intergroup differences were found in the number of muscle contractions and lactate concentration.

Low-level laser therapy, at 60 J/cm2 associated with a Biosilicate(®) increase in bone deposition and indentation biomechanical properties of callus in osteopenic rats.

We investigate the effects of a novel bioactive material (Biosilicate(®)) and low-level laser therapy (LLLT), at 60 J/cm(2), on bone-fracture consolidation in osteoporotic rats. Forty female Wistar rats are submitted to the ovariectomy, to induce osteopenia. Eight weeks after the ovariectomy, the animals are randomly divided into four groups, with 10 animals each: bone defect control group; bone defect filled with Biosilicate group; bone defect irradiated with laser at 60 J/cm(2) group; bone defect filled with Biosilicate and irradiated with LLLT, at 60 J/cm(2) group. Laser irradiation is initiated immediately after surgery and performed every 48 h for 14 days. Histopathological analysis points out that bone defects are predominantly filled with the biomaterial in specimens treated with Biosilicate. In the 60-J/cm(2) laser plus Biosilicate group, the biomaterial fills all bone defects, which also contained woven bone and granulation tissue. Also, the biomechanical properties are increased in the animals treated with Biosilicate associated to lasertherapy. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation as well as indentation biomechanical properties.

Comparative effects of low-intensity pulsed ultrasound and low-level laser therapy on injured skeletal muscle.

OBJECTIVE: The main purpose of this study was to compare the effects of low-intensity pulsed ultrasound (US) and low-level laser therapy (LLLT) on injured skeletal muscle after cryolesion by means of histopathological analysis and immunohistochemistry for cyclo-oxygenase-2 (COX-2). BACKGROUND AND METHODS: Thirty-five male Wistar rats were randomly distributed into four groups: intact control group with uninjured and untreated animals; injured control group with muscle injury and no treatment; LLLT-treated group with muscle injury treated with 830-nm laser; and US-treated group with muscle injury treated with US. Treatments started 24 h postsurgery and were performed during six sessions. RESULTS: LLLT-treated animals presented minor degenerative changes of muscle tissue. Exposure to US reduced tissue injuries induced by cryolesion, but less effectively than LLLT. A large number of COX-2 positive cells were found in untreated injured rats, whereas COX-2 immunoexpression was lower in both LLLT- and US-treated groups. CONCLUSION: This study revealed that both LLLT and US therapies have positive effects on muscle metabolism after an injury in rats, but LLLT seems to produce a better response.