Reliability of the modified Gross Motor Function Measure-88 (GMFM-88) for children with both Spastic Cerebral Palsy and Cerebral Visual Impairment: A preliminary study.

Perez et al. (2015) tested whether the adapted GMFM-88 gives steady scores for kids who have both cerebral palsy and cerebral visual impairment. Two therapists watched the same children twice, one week apart, and scored 88 gross-motor items on video.

The team wanted to know: do the scores stay the same when the same rater watches again, and when a second rater watches?

Both test-retest and inter-rater reliability were excellent. ICC values ranged from 0.94 to 1.00, well above the usual 0.90 cutoff for clinical tools.

In plain words, the adapted GMFM-88 gives repeatable scores for children with CP plus CVI, so therapists can trust the numbers they record.

Laposa et al. (2017) is the direct next step. Using the same CP+CVI group, they showed children score higher on the adapted GMFM-88 than on the original version. The 2015 paper proves the tool is reliable; the 2017 paper proves it is also more accurate.

Hattier et al. (2011) adapted the Berg Balance Scale for clients with severe intellectual and visual disabilities and also found high reliability (ICC = 0.95). Both studies tell the same story: when you tweak a motor test for visual impairment, reliability stays strong.

Marsack-Topolewski et al. (2025) tested a game-based visual intervention for CVI and found no added benefit from adaptive algorithms. That null result does not clash with the GMFM-88 work; it simply shows visual-perception training is a different puzzle from motor measurement.

If you assess children who have both CP and cerebral visual impairment, switch to the CVI-adapted GMFM-88. The 2015 data give you confidence that scores will not bounce around because of rater differences or test-day noise. Use the tool for baseline, goal-setting, and progress tracking without worrying that visual deficits are skewing the numbers.