Assessing gross motor function in cerebral palsy - What standardized scores do not tell us

Sep 29, 2026

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Commentary on the original article by Duran et al. addressing how standardized gross motor function scores in cerebral palsy (CP) may not reflect capacities that matter in daily life. The author highlights strengths and clinical utility of GMFM-66 centile curves while noting the complexity and limited generalizability given therapy intensity differences across settings. The discussion contrasts capacity-focused standardized assessment with contemporary ICF-informed emphasis on everyday activity performance, and proposes complementing reference centiles with controlled studies and parent-report measures such as GM-FR.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Conflicts of interest and data availability

Author background and references

GMFM-66: clinical value and analytical approach

Therapy intensity and generalizability

Capacity-based scoring vs everyday functioning (ICF)

GM-FR as a complementary measure

Implications for future controlled research

CONFLICT OF INTEREST STATEMENT The author has stated that they had no interests which might be perceived as posing a conflict or bias. DATA AVAILABILITY STATEMENT Data sharing is not applicable as no datasets were generated or analysed in this work. ORCID Laura A. Prosser [https://orcid.org/0000-0002-8427-3051](https://orcid.org/0000-0002-8427-3051) REFERENCES 1. Dan B, Rosenbaum P, Carr L, Gough M, Coughlan J, Nweke N. Proposed updated description of cerebral palsy. Dev Med Child Neurol. 2025; 67: 700–9. 2. MacWilliams BA, Prasad S, Shuckra AL, Schwartz MH. Causal factors affecting gross motor function in children diagnosed with cerebral palsy. PLoS One. 2022; 17: e0270121. 3. Staudt LA, Sargent B, Chen L, Fowler EG. Selective Control Assessment of the Lower Extremity for Infants and Toddlers (Mini-SCALE): Development and validation of a clinical assessment. Dev Med Child Neurol. 2026; 68: 211–7. 4. Peyton C, Aaby D, Barbosa VM, Boswell L, de Regnier RA, Bos AF, et al. Baby Observational Selective Control AppRaisal (BabyOSCAR): Scores at 3 months predict functional ability, spastic cerebral palsy distribution, and diagnosis at 2 years. Dev Med Child Neurol. 2024; 66: 1521–8. 5. Fowler EG, Staudt LA, Greenberg MB, Oppenheim WL. Selective Control Assessment of the Lower Extremity (SCALE): development, validation, and interrater reliability of a clinical tool for patients with cerebral palsy. Dev Med Child Neurol. 2009; 51: 607–14. | Received: 5 August 2025
DOI: 10. 1111/dmcn.16480 | Accepted: 7 August 2025 | | | --- | --- | --- | | Assessing gross motor function in cerebral palsy: What standardized scores do not tell us | | | | Peter Rosenbaum
McMaster University – Paediatrics, CanChild, Hamilton, Ontario, Canada
Developed in the late 1980s, the Gross Motor Function Measure (GMFM)1 was among the first formally validated clinical tools to evaluate change over time in gross motor function in young people with cerebral palsy (CP). Its current interval-level version has 66 items and is widely used around the world. Duran et al.2 offer an elegant, innovative but complex statistical approach to the analysis of GMFM-66 change scores using extensive longitudinal data available in their Centre for Prevention and Rehabilitation at the University of Cologne: ‘The centile curves … agreed very well with the reference curves of Hanna et al. and Smits et al. It therefore seems clearer in everyday clinical practice to use only one GMFM-66 centile curve.’ The main advantage of their findings appears to be that these data expand the age range of previous studies.
Reading this paper elicited several reflections. The first is delight that the GMFM (with which our research group [CanChild Centre] is closely connected) continues to be both used and further explored, as has happened in this study. Atthe same time, as a clinician and health services researcher, I find both the methods and the potential application of the | | approach that has been validated here to be complex and likely beyond the scope of many frontline clinicians.
A second observation is that the extent and relative intensity of therapy services for young people with CP reported here is considerably greater than are available in most places. Thus, if in fact physiotherapy is making a major difference to the functional status of these children and adolescents, the findings from this study may have limited generalizability across the world, where therapy resources are much more limited.
This leads to my third and, I believe, most important thought. When the GMFM was created over 35 years ago, clinicians and health services researchers alike implicitly believed that whatever we were assessing, we needed an account of capacity ([i.e. best](i.e. best) performance under standard conditions) . Our interventions were directed at what the World Health Organization's International Classification of Functioning, Disability and Health (ICF) frame

FAQs

What is the central message about GMFM-66 standardized scores in CP?

Standardized scores and centile curves can be valuable, but they may not capture what patients’ daily-life functioning actually reflects. The author emphasizes the gap between best performance under standard conditions and meaningful everyday activity outcomes.

Why does the author question generalizability of the study’s findings?

The commentary notes that reported therapy intensity is higher than what is available in many settings. If therapy differences drive outcomes, the results may not generalize globally where resources are more limited.

How does the commentary relate the GMFM framework to the ICF?

The author explains that the original GMFM development targeted body structure and function, whereas modern thinking influenced by the ICF shifts toward everyday performance of activities in real environments, with less focus on score changes in standardized tests.

Sep 29, 2026

Upload by Jake