Developmental Milestone Source Bright Futures Category Physical Expected age 24 No additional description of this milestone is available. Represented Developmental Observations IDOB#5264008 Walks down stairs without support, putting both feet on each step IDOB#5263002 Walks down stairs with support, putting both feet on each step IDOB#5261000 Walks up stairs without support, putting both feet on each step IDOB#5259009 Walks up stairs with support, putting both feet on each step