Measuring skeletal muscle morphology and architecture with imaging modalities in children with cerebral palsy: a scoping review

Aim: To investigate the use of ultrasound and magnetic resonance imaging (MRI) methodologies to assess muscle morphology and architecture in children with cerebral palsy (CP). Method: A scoping review was conducted with systematic searches of Medline, Embase, Scopus, Web of Science, PubMed, and PsycInfo for all original articles published up to January 2019 utilizing ultrasound and/or MRI to determine morphological and architectural properties of lower limb skeletal muscle in children with CP. Results: Eighty papers used ultrasound (n=44), three-dimensional ultrasound (n=16), or MRI (n=20) to measure at least one muscle parameter in children and adolescents with CP. Most research investigated single muscles, predominantly the medial gastrocnemius muscle, included children classified in Gross Motor Function Classification System levels I (n=62) and II (n=65), and assessed fascicle length (n=35) and/or muscle volume (n=35). Only 21 papers reported reliability of imaging techniques. Forty-six papers assessed measures of Impairment (n=39), Activity (n=24), and Participation (n=3). Interpretation: Current research study design, variation in methodology, and preferences towards investigation of isolated muscles may oversimplify the complexities of CP muscle but provide a foundation for the understanding of the changes in muscle parameters in children with CP.