Is a heel wedge the same as a rearfoot post or do they at least produce the same effect? I haven’t been able to find a clear answer on this. I know that a medial heel wedge based on O’sullivan is on the outside of the bottom of the shoe on the medial side that corrects pes valgus. What about medial rearfoot post?

Heel wedges are a special type of orthotics that are inserted into shoes to help absorb forces at heel contact. They also help alter the alignment of the calcaneus. See Fig 1. Ref 1.

A medial heel wedge is also known as a Thomas heel and it helps correct calcaneal valgus by tilting the heel into varus and may also be helpful in treatment of symptomatic pes planus and plantar fascitis. Ref 2.

A rear heel wedge is not the same thing as a rearfoot post. A rearfoot post is described as a wedge of orthotic material added to the underside of the heel of a casted orthotic in order to increrase the contact area, stabilize the orthosis at heel contact and control excess rearfoot frontal plane movement. There can also be forefoot posts (improves medial column stability), bar posts (improves lateral column stability) in addition to rearfoot posts (as earlier described, imposes rearfoot control). See Fig 2. Ref 3.

Extrinsic rearfoot posts are available in different materials and rigidities depending on the patient’s weight and type of orthosis. Extrinsic  rearfoot posts invert or evert the orthosis heel by beveling the inferior surface to a specific degree. A varus rearfoot  post, for instance, inverts the heel while a valgus rearfoot post everts the heel. Ref 4.

Ref 1; Cikulin-Kulinski K. Physical Therapy Clinical Handbook for PTAs. 2017. 3rd Edition. Jones & Bartlett Learning. Part 3. Musculoskeletal Interventions. Table 3-37 Orthotics I: Orthopedic Shoes (continued). Pg 172.

Ref 2, Ref 3, Ref 4.