How do I know my baby’s legs aren’t forced into a squat? The way the knees are spread changes as Baby grows up.- Before he reaches 3-4 months, Baby’s knees should be open as wide as his pelvis, with his ankles on the same axis as his knees. When you hold him in your arms you can see he snuggles on your chest: this is the most physiological position for him. - At about 3-4 months, as Baby discovers new motor skills, he can grab his ankles and naturally open his pelvis, he can now «embrace» the wrapper with his knees. - The wrapper’s body type is also important for the position.