Independent Walking: 9 to 18 months
Once your baby gains control of her upper body, has learned to turn at the waist, and can alternate her legs, she's ready to bring all these motor skills together for the big finale: taking her first unaided steps. She'll adopt the distinct posture of a new walker: feet wide apart, legs slightly crouched, belly protruding, and arms held high. This strange gait provides a base of support. Upheld arms not only help your toddler achieve balance but stabilize her upper body, so she can concentrate on her lower half.
Because babies don't yet have the balance to stay on one leg for very long, they quickly slap their raised foot down and tend to toddle in short steps. Learning to walk is such a demanding task that it's not unusual for a baby to lose some previous motor skills temporarily. Researchers have found, for example, that new walkers revert to double-handed reaching even though they've mastered single-handed grabbing months before. The theory is that the brain needs to reorganize itself as a new skill is learned. After a few weeks, when arms are no longer held high during walking, toddlers return to one-handed reaching.
Skill builder: Give your baby plenty of safe areas to walk in at home so she can learn to negotiate all kinds of floors. Barefoot is best indoors. Once she's somewhat steady on her feet, dress her in soft, flexible shoes and let her walk outside on grass. Soon your toddler will be hard to stop, as she parlays her walking skills into running, climbing, jumping, hopping, and, maybe someday, kickboxing.