An image alignment guide for producing images for producing a knee brace has an arm carrying a focal angle tube, a mechanism for positioning the arm against the lateral side of the leg of a patient, and a mechanism for setting the level of the brace. The guide is used in method of preparing such images involving taking images with the image alignment guide against the lateral side of a patient's leg at an anterior-posterior mid-line thereof with the focal angle tube at the side of the knee and at a distance therefrom, respectively, measuring the length of the patient's leg from the patella center to a position on the leg at which a shell of a brace to be produced is to be located, measuring the crest of the tibia using a tibial contour guide and sending all images, readings and measurements obtained to a knee brace manufacturer.
