While scanning a AFO, many practitioners prefer using a fixture to support a patient's leg. During shape capture it's important to position yourself so you may freely rotate around while pointing the iPhone towards the patient.
Because a AFO is such a large shape, we recommend sitting on a swivel chair while scanning. Not only will this lower you to the patient's level, but will give you the freedom to move easily during a scan. While it's ultimately up to you to decide which technique works best, we believe following video will help get your started.