Kamdyn started army crawling around 11 months, about a month after she could sit up really well. She looked like a little inch-worm, scooting her body along.
In the months since then, about 6 months to be exact, we have encouraged her to use her knees more, even though she hates it. We have been using hip helpers to encourage her legs to stay together. Kamdyn has made great strides in upper body strength by pushing herself up to sitting, which I also think has to do with her improvements in fine motor skills. Now, her crawling is less army crawl/inch-worm and more of a modified crawl, where she uses her knees, but they are still pushed out to the side.
There you have the evolution of Kamdyn's crawl. And as you can see, the two great motivators are #1 FOOD and #2 keeping up with brother and sister.
Around 19 months old, Kamdyn took her first quadraped crawl. After about a month of practicing, here she is:
