Background: Given the variety of available hand-held dynamometers and their different handle shapes, reliability studies are needed.Objectives: To compare the accuracy and reliability between three different hand-held dynamometers and analyze the influence of their handles on grip strength. Methods: The tests were performed with the Jamar ® dynamometer, the Takei ® dynamometer and the EMG System Manual Transducer with modified handle. Eighteen healthy volunteers aged 20.0±1.3 years without history of musculoskeletal disorders or trauma in the evaluated limbs were included. Data normality was tested using the Shapiro-Wilk test. To verify possible differences between the dynamometers, repeated measures ANOVA was administered, followed by Tukey post-hoc tests. Reliability between measurements was evaluated using intraclass correlation coefficient (ICC) and agreement was tested using Bland and Altman plots. The dynamometers calibration process was evaluated using linear regressions. Results: We observed statistically significant differences on the female group between the Jamar ® and the Takei ® dynamometers (females p<0.001 and males p=0.022) and the EMG System Manual Transducer (female p<0.001 and males p=0.007). However, the Takei ® dymamometer and the EMG System Manual Transducer were similar for both female (p=0.161) and male groups (p=0.850). Although acceptable values of intraclass correlation coefficients between measurements were identified, low agreement between the Jamar ® dynamometer and all other instruments was found. Conclusions: The results demonstrated that there is an influence of the dynamometer's handle shapes on the measurements of grip strength. Furthermore, the results demonstrated the need for previous calibration of this type of instrument.Keywords: dynamometer; grip strength; physical therapy.
ResumoContextualização: Dada a variedade de dinamômetros disponíveis para mensurar a força de preensão manual com diferentes formatos de empunhaduras, estudos de confiabilidade fazem-se necessários. Objetivos: Comparar a exatidão e a precisão das medidas de três dinamômetros distintos e analisar a influência do perfil de empunhadura de cada um. Métodos: Os testes foram realizados com os dinamômetros Jamar ® , Takei ® e o Transdutor Manual EMG System com empunhadura modificada. Foram avaliados 18 voluntários saudáveis, com idade de 20±1,3 anos, sem histórico de doença musculoesquelética ou traumas nos membros avaliados. A normalidade dos dados foi testada por meio do teste Shapiro-Wilk. Para verificar as possíveis diferenças entre as medições dos dinamômetros, aplicou-se uma ANOVA para medidas repetidas seguida do post-hoc de Tukey. A confiabilidade entre as medidas foi avaliada por meio do Coeficiente de Correlação Intraclasse (CCI), e a concordância foi testada utilizando o procedimento de Bland e Altman. Para o procedimento de calibração dos dinamômetros, procedeu-se à análise de regressão linear e de covariância. Resultados: Observou-se diferença estatisticamente significativa entre o dinam...