Orthotics are more commonly known as arch supports, yet this is only one role they fill. When walking or running, arch supports ensure the alignment of your lower back, ankles, knees, and hips as well. To choose the best orthotics it helps to match them with your shoes. In some cases, they may need to be trimmed in order to fit into your shoes properly. Every time you trim some off, check to see how well the supports fit. Continue to do this until they fit perfectly. Once you have made your choice it helps to wear them around the house first.