Functional status and muscle strength in people with Duchenne muscular dystrophy living in the community

Abstract

Objective: To describe activity limitation of people with Duchenne muscular dystrophy who are living in the community and to correlate it with age and muscle strength. Design: Descriptive, correlational. Subjects: Twenty-seven children with Duchenne muscular dystrophy aged 7-14 years who are living in the community. Methods: The subjects' activity limitation was evaluated using the Functional Independence Measure and the muscle strength of their major upper and lower limb muscles was evaluated with manual muscle testing. The Functional Independence Measure was correlated with age and manual muscle testing, and the pattern of activities of daily living limitations and factors related to it were analysed. Results: There were significant correlations between age and averaged MMT score (Spearman's rho = -0.63, p < 0.01), age and Functional Independence Measure motor score (rho = -0.52, p < 0.01), and Functional Independence Measure motor score and averaged manual muscle testing (rho = 0.77, p < 0.01). At similar manual muscle testing level, children with good cognitive function (Functional Independence Measure cognitive score ≥26) showed significantly higher Functional Independence Measure motor scores than those with poor cognitive function (Mann-Whitney U test, p < 0.01). For individual Functional Independence Measure items, eating and bowel management were the easier, whereas transfer and stair climbing were the more difficult. Patients with mean muscle strength ≥grade 3 were rated as relatively independent, while those with a mean muscle strength < 0.05). Conclusion: Activities of daily living in patients with Duchenne muscular dystrophy are related to age and muscle strength, and manual muscle testing grade 3 is an important cut-off point to predict their disability. © 2004 Taylor & Francis.