The use of nonlinear analysis in understanding postural control: A scoping review.

Nonlinear analyses have emerged as an approach to unraveling the intricate dynamics and underlying mechanisms of postural control, offering insights into the complex interplay of physiological and biomechanical factors. However, achieving a comprehensive understanding of the application of nonlinear analysis in postural control studies remains a challenge due to the various nonlinear measurement methods currently available. Thus, this scoping review aimed to identify existing nonlinear analyses used to study postural control in both dynamic and quiet tasks, and to summarize and disseminate the available literature on the use of nonlinear analysis in postural control. For this purpose, a scoping review was conducted and reported following the PRISMA Extension for Scoping Reviews (PRISMA-ScR) Checklist and Explanation. Searches were conducted up to July 2023 on PubMed/Medline, Embase, CINAHL, Web of Science, and Google Scholar databases, resulting in the inclusion of 397 unique studies. The main classes employed among the studies were entropy-based, fractal-based, quantification of recurrence plots, and quantification of stability, with a total of 91 different algorithms distributed among these classes. The most common condition used to study postural control was quiet standing, followed by dynamic standing and gait tasks. Although various algorithms were utilized for this purpose, sample entropy was employed in 43% of studies to explore mechanisms related to postural control. Among them, 28% were in quiet standing, 3.27% were in dynamic standing, and 4.78% to study postural control during the gait. The results also provide insights into nonlinear analysis for future studies, concerning the complexity and interactions within the postural control system across various task demands.

Effects of different fluences of low-level laser therapy in an experimental model of spinal cord injury in rats.

The aim of this study was to evaluate the in vivo response of different fluences of low-level laser therapy (LLLT) on the area of the injury, inflammatory markers, and functional recovery using an experimental model of traumatic spinal cord injury (SCI). Thirty two rats were randomly divided into four experimental groups: control group (CG), laser-treated group 500 J/cm2 (L-500), laser-treated group 750 J/cm2 (L-750), and laser-treated group 1000 J/cm2 (L-1000). SCI was performed by an impactor equipment (between the ninth and tenth thoracic vertebrae), with a pressure of 150 kdyn. Afterwards, the injured region was irradiated daily for seven consecutive sessions, using an 808-nm laser, at the respective fluence of each experimental groups. Motor function and tactile sensitivity were performed on days 1 and 7 post-surgery. Animals were euthanized on the eighth day after injury, and the samples were retrieved for histological and immunohistochemistry analyses. Functional evaluation and tactile sensitivity were improved after LLLT, at the higher fluence. Additionally, LLLT, at 750 and 1000 J/cm2, reduces the lesion volume and modulates the inflammatory process with decrease of CD-68 protein expression. These results suggest that LLLT at higher doses was effective in promoting functional recovery and modulating inflammatory process in the spinal cord of rats after SCI.

Low level laser therapy accelerates bone healing in spinal cord injured rats.

Bone loss occurs rapidly and consistently after the occurrence of a spinal cord injury (SCI), leading to a decrease in bone mineral density (BMD) and a higher risk of fractures. In this context, the stimulatory effects of low level laser therapy (LLLT) also known as photobiomodulation (PBM) have been highlighted, mainly due to its osteogenic potential. The aim of the present study was to evaluate the effects of LLLT on bone healing using an experimental model of tibial bone defect in SCI rats. Twenty-four female Wistar rats were randomly divided into 3 groups: Sham group (SG), SCI control group (SC) and SCI laser treated group (SL). Two weeks after the induction of the SCI, animals were submitted to surgery to induce a tibial bone defect. Treatment was performed 3days a week, for 2weeks, at a single point over the area of the injury, using an 808nm laser (30mW, 100J/cm(2); 0.028cm(2), 1.7W/cm², 2.8J). The results of the histological and morphometric evaluation demonstrated that the SL group showed a larger amount of newly formed bone compared to the SC group. Moreover, a significant immunoexpression of runt-related transcription factor 2 (RUNX2) was observed in the SL group. There was no statistical difference in the biomechanical evaluation. In conclusion, the results suggest that LLLT accelerated the process of bone repair in rats with complete SCI.

Investigation of the Comparative Effects of Red and Infrared Laser Therapy on Skeletal Muscle Repair in Diabetic Rats.

OBJECTIVE: The aim of this study was to evaluate the in vivo response of 2 different laser wavelengths (red and infrared) on skeletal muscle repair process in diabetic rats. DESIGN: Forty Wistar rats were randomly divided into 4 experimental groups: basal control-nondiabetic and muscle-injured animals without treatment (BC); diabetic muscle-injured without treatment (DC); diabetic muscle-injured, treated with red laser (DCR) and infrared laser (DCIR). The injured region was irradiated daily for 7 consecutive days, starting immediately after the injury using a red (660 nm) and an infrared (808 nm) laser. RESULTS: The histological results demonstrated in both treated groups (red and infrared wavelengths) a modulation of the inflammatory process and a better tissue organization located in the site of the injury. However, only infrared light significantly reduced the injured area and increased MyoD and myogenin protein expression. Moreover, both red and infrared light increased the expression of the proangiogenic vascular endothelial growth factor and reduced the cyclooxygenase 2 protein expression. CONCLUSION: These results suggest that low-level laser therapy was efficient in promoting skeletal muscle repair in diabetic rats. However, the effect of infrared wavelength was more pronounced by reducing the area of the injury and modulating the expression proteins related to the repair.

Musculoskeletal Atrophy in an Experimental Model of Knee Osteoarthritis: The Effects of Exercise Training and Low-Level Laser Therapy.

OBJECTIVE: The aim of this study was to evaluate the effects of an exercise training protocol and low-level laser therapy (and the association of both treatments) on musculoskeletal atrophy using an experimental model of knee osteoarthritis (OA). DESIGN: Fifty male Wistar rats were randomly divided into five groups: control group, knee OA control group, OA plus exercise training group, OA plus low-level laser therapy group, and OA plus exercise training associated with low-level laser therapy group. The exercise training and the laser irradiation started 4 wks after the surgery, 3 days per week for 8 wks. The exercise was performed at a speed of 16 m/min, 3 days per week, 50 mins per day, for 8 wks. Laser irradiation was applied at two points of the left knee joint (medial and lateral), for 24 sessions. RESULTS: The results showed that both trained groups (irradiated or not) presented a significant increase in the muscle cross-sectional area and a decrease in muscle fiber density compared with the knee OA control group. Moreover, both trained and laser-irradiated groups demonstrated decreased muscle-specific ring-finger protein 1 and atrogin-1 immunoexpression. CONCLUSIONS: These results suggest that exercise training and low-level laser therapy were effective in preventing musculoskeletal alterations related to atrophy caused by the degenerative process induced by knee OA.

Dor, qualidade de vida, autopercepção de saúde e depressão de pacientes com fibromialgia, tratados com hidrocinesioterapia / Pain, quality of life, self perception of health and depression in patients with fibromyalgia, submited to hydrocinesiotherapy

OBJETIVOS: Analisar os efeitos do tratamento hidrocinesioterapêutico na qualidade de vida, percepção de dor e gravidade de episódios depressivos em um grupo de pacientes com fibromialgia. MATERIAIS E MÉTODOS: Foram avaliados 64 indivíduos do sexo feminino, separados em dois grupos: hidrocinesioterapia (n = 33; 58,2 ± 10,6 anos) e grupo controle (n = 31; 59,6 ± 9,4 anos), com diagnóstico de fibromialgia. Os indivíduos foram avaliados através da Escala Analógica Visual de Dor (EVA), o Fibromyalgia Impact Questionnaire (FIQ), e o Inventário de Beck. Os participantes foram submetidos a um tratamento hidrocinesioterápico numa piscina aquecida a 33ºC com duas sessões de 45 minutos por semana, ao longo 15 semanas, num total de 30 sessões. Os exercícios subaquáticos foram: de condicionamento cardiovascular, de força, de mobilidade, de coordenação, de equilíbrio, de alongamento e de relaxamento muscular. Utilizou-se a ANOVA 2×2 e Kruskal-Wallis para análise estatística. RESULTADOS: Foram observadas melhorias estatisticamente significativas na percepção da intensidade da dor (Δ% = -28,2%, p < 0,01), na qualidade de vida (Δ% = -32,4%, p < 0,05) e nos sintomas de depressão (Δ% = -35,4%, p < 0,05) favoráveis ao grupo hidrocinesioterapia comparado ao grupo controle. CONCLUSÕES: O estudo sugere que a hidrocinesioterapia mostrou-se eficaz como terapia alternativa da fibromialgia. No entanto, recomenda novos estudos que testem as associações existentes entre as variáveis analisadas e os programas de intervenção, utilizando as atividades aquáticas, bem como a modificabilidade dos parâmetros de saúde física e psíquica quando estes indivíduos são submetidos a programas de curta, média e longa duração.

OBJECTIVES: The aim of this study was to analyze the effects of treatment by hydrotherapy on quality of life, perception of pain and the severity of depression in a group of patients with fibromyalgia. MATERIALS AND METHODS: We evaluated 64 females divided into two groups: hydrocinesiotherapy (n = 33, 58.2 ± 10.6 years) and control group (n = 31 with 59.6 ± 9.4 years) with clinical diagnosis of fibromyalgia. Individuals were assessed by Visual Analog Scale of Pain (VAS), the Fibromyalgia Impact Questionnaire (FIQ) and the Beck Depression Inventory. Participants underwent a treatment in a hydrotherapy pool heated to 33ºC over a period of 15 weeks, two sessions per week of 45 minutes, a total of 30 sessions. The exercises were underwater: cardiovascular conditioning, strength training, mobility, coordination, balance and still, stretching exercises and muscle relaxation. The ANOVA 2×2 and Kruskall-Wallis was used for statistical analysis RESULTS: There were statistically significant improvements in the perception of pain intensity (Δ% = -28.2%, p < 0, 01), quality of life (Δ% = -32.4%, p < 0, 05) and depression symptoms (Δ% = -35.4%, p < 0, 05) in favor of the Hydrotherapy group compared to the control group. CONCLUSIONS: The study suggests that hydrocinesiotherapy was effective as an alternative therapy for fibromyalgia, however further studies are recommended to test the associations between the variables and intervention programs and using the water activities, and the modifiability of the parameters of physical and mental health when these individuals undergo programs of short, medium and long duration.

Pain, quality of life, self perception of health and depression in patients with fibromyalgia, submited to hydrokinesiotherapy.

OBJECTIVES: The aim of this study was to analyze the effects of treatment by hydrotherapy on quality of life, perception of pain and the severity of depression in a group of patients with fibromyalgia. MATERIALS AND METHODS: We evaluated 64 females divided into two groups: hydrocinesiotherapy (n = 33, 58.2 ± 10.6 years) and control group (n = 31 with 59.6 ± 9.4 years) with clinical diagnosis of fibromyalgia. Individuals were assessed by Visual Analog Scale of Pain (VAS), the Fibromyalgia Impact Questionnaire (FIQ) and the Beck Depression Inventory. Participants underwent a treatment in a hydrotherapy pool heated to 33ºC over a period of 15 weeks, two sessions per week of 45 minutes, a total of 30 sessions. The exercises were underwater: cardiovascular conditioning, strength training, mobility, coordination, balance and still, stretching exercises and muscle relaxation. The ANOVA 2 × 2 and Kruskall-Wallis was used for statistical analysis RESULTS: There were statistically significant improvements in the perception of pain intensity (Δ% = -28.2%, p < 0, 01), quality of life (Δ% = -32.4%, p < 0, 05) and depression symptoms (Δ% = -35.4%, p < 0, 05) in favor of the Hydrotherapy group compared to the control group. CONCLUSIONS: The study suggests that hydrocinesiotherapy was effective as an alternative therapy for fibromyalgia, however further studies are recommended to test the associations between the variables and intervention programs and using the water activities, and the modifiability of the parameters of physical and mental health when these individuals undergo programs of short, medium and long duration.