RELIABILITY OF THE GROSS MOTOR FUNCTION MEASURE IN CEREBRAL-PALSY

The Gross Motor Function Measure (GMFM), an instrument comprising five dimensions devised by Russell and co-workers (7) to measure gross mot or function in children with cerebral palsy (CP) or brain damage, enab les changes in performance status to be evaluated after therapy or whe n monitored over time. We analysed its inter-rater and intra-rater rel iability on the three most difficult dimensions. A video-recording of three children with CP performing test tasks was assessed on two occas ions at an interval of six months by each of the 15 physiotherapists u sing the GMFM manual but without previous experience or training in th e use of the instrument. Mean percentage scores were similar at the fi rst and second assessments. Both inter- and intra-rater reliabilities were good, inter-rater reliability being 0.77 and 0.88 at the first an d second assessments, respectively, and intra-rater reliability 0.68 a t the second assessment. The findings suggest the GMFM to be a useful and reliable instrument for assessing motor function and treatment out come in CP.