# Should My Child Have a WHO-GMM Assessment?

Canonical: https://pinnacleblooms.org/ask/should-my-child-have-a-who-gmm-assessment-and-what-does-it-involve
Publisher: Pinnacle Blooms Network / Bharath Healthcare Laboratories Private Limited

The WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM) is a reference framework describing the wide, normal age ranges for six motor milestones — sitting, crawling, standing and walking — not a stand-alone test. Most children don't need a separate WHO-GMM assessment; clinicians use the windows as one lens within a fuller developmental check. It's most useful when there is a specific concern, such as a child clearly past a window or losing a skill, in which case a proper review is wise.

*Curious whether your little one's rolling, sitting and walking are on track? Here's what the WHO gross-motor windows really tell you.*

## In short
The [WHO Windows of Achievement for Gross Motor Milestones](/who-gmm) (WHO-GMM) is a reference framework — not a stand-alone test — that describes the broad *age ranges* in which healthy children typically reach six motor milestones: sitting without support, hands-and-knees crawling, standing with assistance, walking with assistance, standing alone, and walking alone. Most children do not need a separate "WHO-GMM assessment"; rather, a clinician uses these windows as one lens within a fuller developmental check. It is worth a look if your child seems clearly behind on gross-motor steps, but the windows are deliberately wide because healthy babies vary a great deal.

## What the windows actually involve
The WHO milestones come from a large multi-country study of healthy children, so each milestone is given as a *window* (for example, walking alone anywhere from roughly the end of the first year into the second), not a single deadline:

- **Six gross-motor milestones** — observed through everyday movement, not a pass/fail exam.
- **Wide, overlapping ranges** — designed to reflect normal variation across babies and cultures.
- **Observation, not equipment** — a clinician watches how your child moves, holds posture, bears weight and transitions between positions.
- **One piece of the picture** — gross motor is read alongside fine motor, communication, social and play development.

So the honest answer to "should my child have one?" is: the windows are most useful when there is a *specific* concern — your child is well past a window, has lost a skill, or moves very differently on one side. In those cases the windows become a helpful prompt to seek a proper review.

## When to seek a check
Book a developmental review if your child is clearly past a window (for example, not sitting with support well beyond the typical range, or not walking by around 18 months), has stiff or floppy muscle tone, strongly favours one side, or has lost a skill they once had. Persistent, marked delay deserves prompt attention — early movement support is gentle and effective.

## The Pinnacle way
Developmental measurement supports care planning; diagnosis requires an appropriately qualified healthcare professional., under the care of a qualified clinician — never from an online chart or a single milestone window. Our clinicians use a structured, clinician-administered assessment that places gross-motor progress within your child's whole developmental picture, measured against *their own* baseline so real gains become a clear line. Backed by 2.5 billion+ data points and 25 million+ therapy sessions across 70+ centres, we turn each review into practical [occupational and physical movement support](https://www.pinnacleblooms.org/best-occupational-therapy-center-india-proven-improvement-rate) you can use at home. You can read how the measure works here: [what the AbilityScore is and how it's calculated](/ask/what-is-the-abilityscore-and-how-is-it-calculated).

## Trusted sources
WHO Motor Development Study and Windows of Achievement for six gross-motor milestones; WHO and Nurturing Care guidance on early childhood development; CDC and HealthyChildren (AAP) developmental milestone resources for movement.

**Next step —** Not sure if your child's movement is on track? [Book a developmental assessment](https://www.pinnacleblooms.org/enroll-autism-speech-aba-therapies-india) with a Pinnacle clinician for clear, reassuring answers and a plan if needed.

This is general information, not a diagnosis — individual assessment and diagnosis require an appropriately qualified healthcare professional.

## Sources
- WHO motor development milestones and windows of achievement: https://www.who.int/tools/child-growth-standards/standards/motor-development-milestones
- CDC developmental milestones, including movement: https://www.cdc.gov/child-development
- HealthyChildren (AAP) guidance on early movement development: https://www.healthychildren.org
- Nurturing Care Framework for early childhood development: https://nurturing-care.org

## Connected topics and perspectives
- Assessments: https://pinnacleblooms.org/ask/assessments
- Parent: https://pinnacleblooms.org/ask/lens/stakeholder/parent
- Assessment: https://pinnacleblooms.org/ask/lens/intent/assessment
- Measure: https://pinnacleblooms.org/ask/lens/lifecycle/measure
- Screen: https://pinnacleblooms.org/ask/lens/route/screen
- Early Clarity: https://pinnacleblooms.org/ask/lens/empowerment/early_clarity

## Related question paths

### Understand the subject
- What is the WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM)?: https://pinnacleblooms.org/ask/what-is-the-who-windows-of-achievement-for-gross-motor-milestones-who-gmm-and-what-does-it-assess
- At What Age Is the WHO-GMM Used for a Child?: https://pinnacleblooms.org/ask/at-what-age-is-the-who-gmm-developmental-assessment-used-for-a-child

### Understand assessment
- When is the WHO-GMM indicated, and what are its strengths and limits?: https://pinnacleblooms.org/ask/when-is-the-who-gmm-indicated-and-what-are-its-strengths-and-limits-in-early-childhood
- How does the WHO-GMM compare with the AbilityScore developmental assessment?: https://pinnacleblooms.org/ask/how-does-the-who-gmm-compare-with-the-abilityscore-developmental-assessment

### Explore therapy & support
- How do I check if my child's motor development is on track?: https://pinnacleblooms.org/ask/how-do-i-check-if-my-child-s-motor-development-is-on-track
- How Is a Child's Motor Development Assessed?: https://pinnacleblooms.org/ask/how-is-a-child-s-motor-development-assessed