For measuring leg length, the gold standard is a standing x-ray. However, this may be cost-prohibitive, so we typically start with a cloth measuring tape. We’ll start at the hip and down the leg to the ankle bone for the true leg length. For the functional leg length, we’ll start at the belly button and go down to the ankle bone. If the discrepancy between the two measurements is more than 1 cm, we will correct with a plastic shim which is typically half of the discrepancy.