What are the typical functional mobility milestones for infants as described?

What are the typical functional mobility milestones for infants as described?

• A. Crawls at 9 months; walks at 12-14 months.
• B. Crawls at 3 months; walks at 9 months.
• C. Stands unaided at 4 months and walks at 8 months.
• D. Rolls over but does not crawl or walk until 24 months.

Answer: (A)

Typical gross motor development in infancy follows a relatively predictable sequence. Infants progress from rolling and moving in prone or supine positions to crawling, then standing with support, cruising, and finally independent walking. Crawling around nine months and walking around twelve to fourteen months fit the common window for functional mobility, making this option the best match for typical development. The other possibilities describe skills that usually occur much earlier or much later than is typical—for example, crawling at three months, standing unaided at four months, or walking at eight months are not typical milestones, and delaying crawling or walking until around two years is also outside the usual range.

Typical gross motor development in infancy follows a relatively predictable sequence. Infants progress from rolling and moving in prone or supine positions to crawling, then standing with support, cruising, and finally independent walking. Crawling around nine months and walking around twelve to fourteen months fit the common window for functional mobility, making this option the best match for typical development. The other possibilities describe skills that usually occur much earlier or much later than is typical—for example, crawling at three months, standing unaided at four months, or walking at eight months are not typical milestones, and delaying crawling or walking until around two years is also outside the usual range.