title: Objective evaluation of muscle strength in infants with hypotonia and muscle weakness.
abstract: The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81 typically developing infants, 6-36 months of age, and 17 infants with Prader-Willi Syndrome (PWS) aged 24 months. The inter-rater reliability of the measurement method was good (ICC=.84) and the convergent validity was confirmed by high Pearson's correlations between muscle strength, age, height, and weight (r=.79-.85). A multiple linear regression model was developed to predict muscle strength based on age, height, and weight, explaining 73% of the variance in muscle strength. In infants with PWS, muscle strength was significantly decreased. Pearson's correlations showed that infants with PWS in which muscle strength was more severely affected also had a larger motor developmental delay (r=.75).
authors: Radboud University Nijmegen Medical Centre, Department of Rehabilitation, Pediatric Physical Therapy, Nijmegen, The Netherlands. l.reus@reval.umcn.nl
authors: Linda
authors: L
authors: Reus
authors: Leo A
authors: LA
authors: van Vlimmeren
authors: J Bart
authors: JB
authors: Staal
authors: Anjo J W M
authors: AJ
authors: Janssen
authors: Barto J
authors: BJ
authors: Otten
authors: Ben J
authors: BJ
authors: Pelzer
authors: Maria W G
authors: MW
authors: Nijhuis-van der Sanden
mesh_terms: D016022:Case-Control Studies; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D009123:Muscle Hypotonia / Q000175:diagnosis*; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000175:diagnosis*; D011218:Prader-Willi Syndrome / Q000175:diagnosis*; D015203:Reproducibility of Results