Reliability of hand-held dynamometry for measurement of lower limb muscle strength in children with Duchenne and Becker muscular dystrophy

Abstract

Objective To determine the reliability of hand-held dynamometry (HHD) for lower limb isometric muscle strength measurement in children with Duchenne and Becker muscular dystrophy (DMD/BMD).  Methods A total of 21 children [20 males and one female; mean age was (7.88 ± 2.87) years, ranging between 3.96-14.09 years; mean age at diagnosis was (5.88 ± 2.88) years, ranging between 1.35-12.89 years; mean height was (120.64 ± 16.30) cm, ranging between 97-153 cm; mean body weight was (24.62 ± 9.05) kg, ranging between 14-50 kg] with DMD (19/21) and BMD (2/21) were involved from Rehabilitation Center of Children's Hospital of Fudan University. The muscle strength of hip, knee and ankle was measured by HHD under standardized test methods. The test-retest results were compared to determine the inter-test reliability, and the results among testers were compared to determine the inter-tester reliability.  Results HHD showed fine inter-tester reliability (ICC = 0.762-0.978) and inter-test reliability (ICC = 0.690-0.938) in measuring lower limb muscle strength of children with DMD/BMD. Results also showed relatively poor reliability in distal muscle groups (foot plantar flexion and dorsiflexion).  Conclusions HHD, showing fine inter-tester and inter-test reliability in measuring the lower limb muscle strength of children with DMD/BMD, can be used in monitoring muscle strength changing and assessing effects of clinical interventions.

DOI: 10.3969/j.issn.1672-6731.2015.05.009