Reliability of the Clinical Measurement of Joint Motion and Muscle Length in the Upper and Lower Extremities of Children with Cerebral Palsy: A Systematic Review.

Reliability of joint motion and muscle length measurement in children with cerebral palsy was examined. Twenty-one studies of intraobserver and/or interobserver reliability were reviewed: joint motion of upper extremities in four and lower extremities in 13; muscle length of upper extremities in one and lower extremities in 15. Intraclass correlation coefficients for goniometric interobserver reliability varied widely for joint motion (range 0.38-0.92) and muscle length (range 0.20-0.95). Inclusion of an error measurement to provide clinicians with a value indicating true change was limited. Further research is required to determine intraobserver and interobserver reliability for these important pediatric clinical measurements.