Is it normal for a child to crawl in an unusual way (backward, on one leg, on the bottom) or not to crawl at all?
Applies to age: 6–18 months
In short
In the WHO study, some healthy children did not crawl on hands and knees (4.3%), and instead, for example, shuffled on their bottom or crawled on their stomach. The window for crawling on hands and knees is 5.2–13.5 months (1st–99th percentile).
What is normal
All claims: international norm
- In the WHO study, 4.3% of children (35 of 816) were not observed to crawl on hands and knees, so they were not included in the analysis of this milestone.
Source: WHO – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Some 35 children (4.3%) were never observed to crawl on hands and knees, and thus were not included in the analysis of this milestone.
WHO · open the source · accessed: 2026-10-14 · license [1]
- Other studies also report that crawling is sometimes skipped and the child moves in another way instead, for example shuffling on the bottom or crawling on the stomach (this was also the case in the WHO study).
Source: WHO – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Other studies also report that this milestone is sometimes not performed and that instead some other type of locomotion is used, such as bottom shuffle or crawling on the stomach, as was observed in the MGRS
WHO · open the source · accessed: 2026-10-14 · license [1]
- The window for healthy children to achieve crawling on hands and knees is 5.2–13.5 months (1st–99th percentile); the window for walking alone is 8.2–17.6 months.
Source: WHO – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
The estimated 1st and 99th percentiles in months are: 3.8, 9.2 (sitting without support), 4.8, 11.4 (standing with assistance), 5.2, 13.5 (hands-and-knees crawling), 5.9, 13.7 (walking with assistance), 6.9, 16.9 (standing alone) and 8.2, 17.6 (walking alone).
WHO · open the source · accessed: 2026-10-14 · license [1]
- The WHO developmental windows describe normal variation in the age at which healthy children reach milestones.
Source: WHO – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
The windows represent normal variation in ages of milestone achievement among healthy children.
WHO · open the source · accessed: 2026-10-14 · license [1]
When to worry
All claims: international norm
- The WHO achievement windows signal the need for appropriate screening when a child is late in reaching milestones.
Source: WHO – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
They are recommended for descriptive comparisons among populations, to signal the need for appropriate screening when individual children appear to be late in achieving the milestones, and to raise awareness about the importance of overall development in child health.
WHO · open the source · accessed: 2026-10-14 · license [1]
The sources in our registry do not say when to see a doctor.
international norm “International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.
Sources
- WHO (who.int)License: CC BY-NC-SA 3.0 IGO. Source: WHO (who.int). Content summarized and translated by the editors; changed relative to the original. WHO does not endorse this site or its content.