ABSTRACT
Duchenne muscular dystrophy (DMD) and Spinal muscular atrophy (SMA) causes significant disability and progressive functional impairment. Readily available instruments that assess functionality, especially in advanced stages of the disease, are required to monitor the progress of the disease and the impact of therapeutic interventions. OBJECTIVE: To describe the development of a scale to evaluate upper limb function (UL) in patients with DMD and SMA, and describe its validation process, which includes self-training for evaluators. PATIENTS AND METHOD: The development of the scale included a review of published scales, an exploratory application of a pilot scale in healthy children and those with DMD, self-training of evaluators in applying the scale using a handbook and video tutorial, and assessment of a group of children with DMD and SMA using the final scale. Reliability was assessed using Cronbach and Kendall concordance and with intra and inter-rater test-retest, and validity with concordance and factorial analysis. RESULTS: A high level of reliability was observed, with high internal consistency (Cronbach a = 0.97), and inter-rater (Kendall W = 0.96) and intra-rater concordance (r = 0.97 to 0.99). The validity was demonstrated by the absence of significant differences between results by different evaluators with an expert evaluator (F = 0.023, p > .5), and by the factor analysis that showed that four factors account for 85.44% of total variance. CONCLUSIONS: This scale is a reliable and valid tool for assessing UL functionality in children with DMD and SMA. It is also easily implementable due to the possibility of self-training and the use of simple and inexpensive materials.
Subject(s)
Disability Evaluation , Muscular Atrophy, Spinal/physiopathology , Muscular Dystrophy, Duchenne/physiopathology , Adolescent , Case-Control Studies , Child , Child, Preschool , Disease Progression , Factor Analysis, Statistical , Female , Humans , Male , Observer Variation , Pilot Projects , Reproducibility of Results , Severity of Illness Index , Upper ExtremityABSTRACT
INTRODUCTION: In this study we aimed to determine the maximal isometric muscle strength of a healthy, normal-weight, pediatric population between 6 and 15 years of age using hand-held dynamometry to establish strength reference values. The secondary objective was determining the relationship between strength and anthropometric parameters. METHODS: Four hundred normal-weight Chilean children, split into 10 age groups, separated by 1-year intervals, were evaluated. Each age group included between 35 and 55 children. RESULTS: The strength values increased with increasing age and weight, with a correlation of 0.83 for age and 0.82 for weight. The results were similar to those reported in previous studies regarding the relationships among strength, age, and anthropometric parameters, but the reported strength differed. CONCLUSIONS: These results provide normal strength parameters for healthy and normal-weight Chilean children between 6 and 15 years of age and highlight the relevance of ethnicity in defining reference values for muscle strength in a pediatric population. Muscle Nerve 55: 16-22, 2017.
Subject(s)
Hand Strength/physiology , Isometric Contraction/physiology , Muscle Strength Dynamometer , Muscle Strength/physiology , Muscle, Skeletal/physiology , Adolescent , Anthropometry , Child , Female , Humans , Male , Reference Values , Reproducibility of ResultsABSTRACT
La distrofia muscular de Duchenne (DMD) y la Atrofia músculo espinal (AME) determinan discapacidad y compromiso funcional progresivo. Se requiere de instrumentos fácilmente disponibles, que evalúen la funcionalidad, especialmente en etapas avanzadas de la enfermedad, para monitorizar evolución e impacto de intervenciones terapéuticas. Objetivo: Reportar el desarrollo de escala para evaluar la función de las extremidades superiores (EESS) en pacientes con DMD y AME, y describir su proceso de validación que incluye autoentrenamiento para evaluadores. Pacientes y Método: El desarrollo de la escala incluyó revisión de escalas publicadas, aplicación exploratoria de escala inicial en niños sanos y con DMD, autoentrenamiento de evaluadores en aplicación de escala definitiva utilizando manual y vídeo tutorial y aplicación de escala en grupo de niños con DMD y AME. Se evaluó confiabilidad con coeficiente de Cronbach y de Kendall y concordancia con test-retest intra e inter-evaluadores, y validez con análisis de concordancia y factorial. Resultados: Se observó alto grado de confiabilidad, con alta consistencia interna (a de Cronbach = 0,97) y concordancia interevaluadores (W de Kendall = 0,96) e intraevaluadores (r = 0,97 a 0,99). La validez se demostró por la inexistencia de diferencias significativas entre resultados de distintos evaluadores con evaluador experto (F = 0,023, p > 0,5) y análisis factorial, que mostró que 4 factores explican el 85,44% de varianza total. Conclusiones: Esta escala de evaluación es un instrumento confiable y válido para evaluar la funcionalidad de EESS en niños con DMD y AME. Además, es de fácil implementación por la posibilidad de autoentrenamiento y el uso de materiales simples y de bajo costo.
Duchenne muscular dystrophy (DMD) and Spinal muscular atrophy (SMA) causes significant disability and progressive functional impairment. Readily available instruments that assess functionality, especially in advanced stages of the disease, are required to monitor the progress of the disease and the impact of therapeutic interventions. Objective: To describe the development of a scale to evaluate upper limb function (UL) in patients with DMD and SMA, and describe its validation process, which includes self-training for evaluators. Patients and Method: The development of the scale included a review of published scales, an exploratory application of a pilot scale in healthy children and those with DMD, self-training of evaluators in applying the scale using a handbook and video tutorial, and assessment of a group of children with DMD and SMA using the final scale. Reliability was assessed using Cronbach and Kendall concordance and with intra and inter-rater test-retest, and validity with concordance and factorial analysis. Results: A high level of reliability was observed, with high internal consistency (Cronbach a = 0.97), and inter-rater (Kendall W = 0.96) and intra-rater concordance (r = 0.97 to 0.99). The validity was demonstrated by the absence of significant differences between results by different evaluators with an expert evaluator (F = 0.023, p > .5), and by the factor analysis that showed that four factors account for 85.44% of total variance. Conclusions: This scale is a reliable and valid tool for assessing UL functionality in children with DMD and SMA. It is also easily implementable due to the possibility of self-training and the use of simple and inexpensive materials.
