We have a question from a ProLab client today:
Hi Larry,
I saw one of my partner's pts on Fri. who has had lateral column foot pain for several mos. She was treated in a CAM boot for 4 mos for a presumed stress fx, however, she has no callus formation on XR and has pain diffusely along the 4th and 5th met shafts as well as base (no cuboid pain and no pain localized to the styloid process). She has minimal STJ eversion and upon standing has ~4 degrees of calc varus b/l. When she walks she strikes inverted, stays inverted, and has minimal midfoot pronation. She does not have a cavus foot, just a varus heel and rigid STJ.
She just got custom orthotics in Dec. but there are no modifications to offload her lateral column. So I was thinking about doing a valgus forefoot wedge for sure and then considering a valgus rearfoot wedge but wasn't sure how to put that on the prescription. I'm sending in her current orthotics for modification so that means I can't do the lateral heel skive, right? So my question is: start over from scratch and do the skive or modify existing and if so, what do I put on the Rx for the rearfoot wedge?
ANSWER:
If she has a rigid rearfoot, the lateral skive and lateral wedging is unlikely to help this problem. Instead, our goal should be to transfer pressure off of the lateral column and put it on the medial column.
I recommended an orthosis with the following Rx:
- Vacuum Formed Polypropylene or Direct Milled Polypropylene. Semi-rigid
- Standard or Deep heel cup.
- Wide width. By making the device wider, we better transfer force off of the lateral column onto the medial column
- Cast Fill: Very minimum fill right, minimum fill left. Very minimum fill results in an orthosis that conforms very close to the medial arch of the foot. This will transfer force from the lateral column to the medial column. (Check off Minimum Fill and write in the word "Very")
- Polypropylene rearfoot post. You want a firm post that will not compress laterally. This will result in faster pronation to reduce time (and force) on the lateral column.
- EVA cover to toes glue posterior only.
- Add 1.5mm poron to bottom of cover. This extra layer of cushion can help disperse pressure around the lateral column
- Do not bevel post laterally on right. No lateral bevel will increase the velocity of pronation and decrease time spent on the lateral column.
I think it will be difficult to modify the current orthosis as the most important aspect of this RX is the minimum fill that transfers pressure from lateral to medial.