CORRELATION BETWEEN ELECTROMYOGRAPHIC ACTIVITY AND STRENGTH OF THE FLEXOR MUSCLES OF THE WRIST

INTRODUCTION: In analysing the electromyographic (EMG) signal, researchers are often led to interpret variations of the signal as variation in strength of muscle contraction. However, the relationship between the force exerted and the electrical activity of a muscle are not well established. This is due to the considerable variation of data acquisition and processing techniques, the detection site of the muscles analysed, as well as the alterations in their length and the type of contraction. The object of this paper was to evaluate the correlation between electrical activity and muscular strength. METHODS AND PROCEDURES: The flexor muscles of the wrist of the non dominant member of 21 female volunteers (mean age = 21 years, sd = ± 1.5) with no history of skeletal muscle dysfuntion, were analysed. The EMG signal was captured by active surface electrode (DELSYS), over the belly of the muscle in the longitudinal sense of the fibres, having a gain of 10 Hz. The electrode was coupled to a 16 channel 12/36 electromyograph (AqDados - LYNX TECNOLOGIA ELETRÔNICA LTDA), which permitted a gain of 50 Hz. The system bandwidth was 10 to 500 Hz, with an overall gain of 1,000. The data acquisition rate was 1,000 Hz. In order to eliminate possible interferences, a ground electrode was coupled to the distal segment of the forearm. Muscular strength was measured by means of a load cell (model MM/50 kg, KRATOS), placed perpendicularly in the center of the palm surface of the hand. The electrode and the load cell were connected to a 16 channel signal acquisition system (AQDADOS 4.0, LYNIX). The temperature of the room was kept at 23ºC, ± 1. The EMG registers and the strength were collected simultaneously. Result were obtained from the average of three repetitions, shown in RMS and Kgf respectively. The data was collected with the hand fixed to a device which limited the wrist to 45º of flexion and 45º of extension, providing an isometric contraction. RESULTS AND DISCUSSION: The results demonstrated a positive correlation between electromyographic activity and strength of contraction (r = 0.76) in the 45º flexion position, whereas, for the 45º extension position, the correlation was not significant (r = 0.23), considering the sample analysed. The data suggest that there is a positive correlation between EMG and strength, depending on the position of the muscle analysed

Comparação de diferentes procedimentos de estimulação elétrica neuromuscular utilizados no tratamento da incontinência urinária de esforço feminina : ensaio clínico randomizado

Neuromuscular electrical stimulation (NMES) is widely treatment for stress urinary incontinence (SUI) but there is no consensus in literature regarding the most effective treatment parameters. OBJECTIVE: To compare two NMESintra-vaginal protocols for the treatment of SUI in women. The study included 20 volunteers with an average age of 55.55±6.51 years and with the clinical diagnosis of SUI. Volunteers were randomly divided into two groups: group 1 (G1) received NMES with medium-frequency current and group 2 (G2) received NMES with low-frequency current. Functional assessments of pelvic floor muscles (PFM) were performed by perineometry. The severity of signs and symptoms were objectively evaluated using the 1 hour pad test and subjectively evaluated using a visual analog scale that measured the discomfort caused by the SUI. Shapiro-Wilk test was used to analyze data normality, and the Friedman test was used to analyze nonparametric data. For analysis of symptoms related to SUI the Fisher exact test and the Mann-Whitney test were used. Significance level of 5% was set for all data analysis. No significant differences (p>0.05) were found between groups for any of the variable assessed. The within group analysis of initial and final evaluations (after NMES) demonstrated significant differences (p0,05) entre os grupos em nenhuma variável avaliada. Na comparação intragrupos das avaliações iniciais e finais (após EENM), houve diferença significativa (p<0,05) na quantidade de urina perdida, no desconforto causado pela incontinência urinária e na pressão perineal. Os procedimentos de EENM utilizados neste estudo foram igualmente eficazes no tratamento da IU

Comparação de diferentes procedimentos de estimulação elétrica neuromuscular utilizados no tratamento da incontinência urinária de esforço feminina: ensaio clínico randomizado

BACKGROUND: Neuromuscular electrical stimulation (NMES) is widely treatment for stress urinary incontinence (SUI) but there is no consensus in literature regarding the most effective treatment parameters. OBJECTIVE: To compare two NMESintra-vaginal protocols for the treatment of SUI in women. METHODS: The study included 20 volunteers with an average age of 55.55±6.51 years and with the clinical diagnosis of SUI. Volunteers were randomly divided into two groups: group 1 (G1) received NMES with medium-frequency current and group 2 (G2) received NMES with low-frequency current. Functional assessments of pelvic floor muscles (PFM) were performed by perineometry. The severity of signs and symptoms were objectively evaluated using the 1 hour pad test and subjectively evaluated using a visual analog scale that measured the discomfort caused by the SUI. Shapiro-Wilk test was used to analyze data normality, and the Friedman test was used to analyze nonparametric data. For analysis of symptoms related to SUI the Fisher exact test and the Mann-Whitney test were used. Significance level of 5% was set for all data analysis. RESULTS: No significant differences (p&gt;0.05) were found between groups for any of the variable assessed. The within group analysis of initial and final evaluations (after NMES) demonstrated significant differences (p<0.05) in amount of urine lost, the discomfort caused by urinary incontinence and perineal pressure for both treatment groups. CONCLUSION: The two NMES protocols applied were equally effective in the treatment of SUI.CONTEXTUALIZAÇÃO: A estimulação elétrica neuromuscular (EENM) é amplamente utilizada no tratamento da incontinência urinária de esforço (IUE), no entanto não há consenso na literatura sobre os parâmetros de tratamento mais eficazes. OBJETIVO: Avaliar os procedimentos de EENM intravaginal no tratamento de mulheres com IUE. MÉTODOS: Participaram do estudo 20 voluntárias com idade média de 55,55±6,51 anos, com diagnóstico clínico de IUE. As voluntárias foram divididas aleatoriamente em dois grupos: grupo 1 (G1), que recebeu EENM com corrente de média frequência, e grupo 2 (G2), com corrente de baixa frequência. A avaliação funcional dos músculos do assoalho pélvico (MAP) foi realizada por meio de perineometria, e a severidade dos sinais e sintomas da IUE foi avaliada, objetivamente, pelo pad test de uma hora e, subjetivamente, pela Escala Visual Analógica (EVA), que mediu o desconforto causado pela incontinência. Para a análise de normalidade dos dados, utilizou-se o teste Shapiro-Wilk, seguido do teste de Friedman para dados não paramétricos. Para a análise dos sintomas relacionados à IUE, usaram-se os testes Exato de Fisher e Mann-Whitney. Em todas as análises, considerou-se o nível de significância de 5%. RESULTADOS: Não houve diferença significativa (p&gt;0,05) entre os grupos em nenhuma variável avaliada. Na comparação intragrupos das avaliações iniciais e finais (após EENM), houve diferença significativa (p<0,05) na quantidade de urina perdida, no desconforto causado pela incontinência urinária e na pressão perineal. CONCLUSÃO: Os procedimentos de EENM utilizados neste estudo foram igualmente eficazes no tratamento da IUE

Comparação das forças ativa e passiva dos músculos do assoalho pélvico de mulheres com e sem incontinência urinária de estresse

Background: The reduction of the pelvic floor muscles (PFM) strength is a major cause of stress urinary incontinence (SUI). Objective: To compare active and passive forces, and vaginal cavity aperture in continent and stress urinary incontinent women. Method: The study included a total of thirty-two women, sixteen continent women (group 1 - G1) and sixteen women with SUI (group 2 - G2). To evaluate PFM passive and active forces in anteroposterior (sagittal plane) and left-right directions (frontal plane) a stainless steel specular dynamometer was used. Results: The anteroposterior active strength for the continent women (mean +/- standard deviation) (0.3 +/- 0.2 N) was greater compared to the values found in the evaluation of incontinent women (0.1 +/- 0.1 N). The left-right active strength (G1=0.43 +/- 0.1 N; G2=0.40 +/- 0.1 N), the passive force (G1=1.1 +/- 0.2 N; G2=1.1 +/- 0.3 N) and the vaginal cavity aperture (G1=21 +/- 3 mm; G2=24 +/- 4 mm) did not differ between groups 1 and 2. Conclusion: The function evaluation of PFM showed that women with SUI had a lower anteroposterior active strength compared to continent women.Contextualização: A redução da força dos músculos do assoalho pélvico (MAP) é a maior causa da incontinência urinária de estresse \ud (IUE). Objetivo: Comparar as forças ativa e passiva e a abertura da cavidade vaginal em mulheres continentes e com IUE. Método: O \ud estudo incluiu um total de 32 mulheres, 16 mulheres continentes (grupo 1 - G1) e 16 mulheres com IUE (grupo 2 - G2). Um espéculo \ud dinamométrico de aço inoxidável foi usado para avaliar as forças ativa e passiva dos MAP nas direções ântero-posterior (plano \ud sagital) e látero-lateral (plano frontal). Resultados: A força ativa ântero-posterior nas mulheres continentes (0,3±0,2 N) foi maior que \ud nas mulheres com IUE (0,1±0,1 N). Não houve diferença entre o G1 e o G2 nos valores de força ativa látero-lateral (G1=0,43±0,1 N; \ud G2=0,40±0,1 N), força passiva (G1=1,1±0,2 N; G2=1,1±0,3 N) e abertura da cavidade vaginal (G1=21±3 mm; G2=24±4 mm). \ud Conclusão: A avaliação da função dos MAP mostrou que mulheres com IUE tiveram uma menor força ativa ântero-posterior quando \ud comparadas com as mulheres continentes