Dennis Kiper, D.P.M.
The foot to me is like a "loose bag of bones." Tied together by the soft tissues, each bone moves on one or more of the planes of motion and moves as much as necessary in order to reduce incoming shock An orthosis to my way of thinking is designed to "assist" the foot and minimize this motion. It does this by aligning the foot to the ground and tightening up the laxity of the foot motion making it more efficient in its course of action(s).
What the SDO does so well, is allow each bone to move through its natural planes of motion in a fluid manner (NO PUN INTENDED). It does not alter these motions and does not restrict them abruptly. It simply guides the structure through its course of action, yet limits the laxity. This is what makes the SDO so easy, accurate and comfortable to wear.
A traditional support (rigid or semi-rigid) on the other hand (in my opinion) holds the foot to a casted position which is rigid to the planes of motion. Granted, if the foot structure feels comfortable to this position and way of walking, and it works in its concept of healing, then that is the bottom line. To me, just because the foot is custom casted to a biomechanical position, does not mean it fits the way that foot works (thats why I hear so many patients say it is very uncomfortable even if it helps). Especially during an injury where the muscles are under tension and spasm and therefore tight and resticted to the correct biomechanical position. This is why in my experience working with traditional orthotics for 15 years, I found so many failures. And I could do very little to adjust that device to make it that much more acceptable to the patient.
The SDO can be adjusted to anyone (as long as that individual is willing to work with you and understands that just because the orthotic fits does not mean that resolution is going to be quick), because the intrinsic muscles of the foot determine that the fit in that position is acceptable to them. We also know that if an orthotic does work, we will need to adjust the alignment position in 1-2 years to compensate for that shift in fit vs biomechanical position.
Does The Ideal Foot Orthotic Exist?
The ideal foot orthotic: "Is there such a thing?" Perhaps not. Can one orthoses meet the needs of all people? Of course not. Is there an orthoses so ideal that can prevent or slow down foot problems? Possibly so, but this needs clarification.The purpose of a foot orthoses is to limit the total range of motion (overpronation) available to the foot as it coils to the ground (called pronation). Most prescription orthoses do this. In fact many non prescription supports do it too. However, the closer the orthoses is to limiting the precise amount of motion and yet, lets the foot move naturally and balanced across the floor, the more comfortable it will be to wear, and above all else produce results.
Foot orthoses unfortunately do not work like eye glasses. You do not get an instant resolution. Some people do respond amazingly quickly, although this is the minority. Some people are more complex for whatever reason and they may take anywheres up to six months to begin to respond favorably. The majority of people feel a 40-60% minimum average improvement in their symptoms within 8 weeks, (this is not the same as being cured). As time continues it is possible to feel like progress has stopped or that the pain is coming back. As you wear the orthoses you begin to absorb the prescription so you may start to feel the residual inflammation and tension temporarily. If your orthoses are comfortable and you are able to wear them most of the time they are working. The healing of biomechanical inflammation takes time. It can take 1-2 years for an orthoses to generate its maximum effective range of healing. As your foot flexibility increases, the optimal position of alignment will change (due to increase in health from reduction in tension and inflammation). Then regardless of your symptoms you need to get another prescription in order to keep your feet and body working to their best efficiency. If your orthoses work correctly you can expect 2-3 changes in your lifetime. Most of these changes should occur in the first to the second year. The next change should be very gradual over the next 4-6 years. After that changes may or may not occur. If they do it will take a long time.
So to clarify the last question, "Is there an orthoses so ideal as to prevent foot problems?" Depends on what problems we are looking to prevent. If we are looking to prevent injuries from inadequate training, excessive distances, increasing mileage too quickly, anatomical or functional abnormalities, accidental sprains or strains, uneven surfaces, and aging, probably not. But if there are biomechanical reasons for something to eventually happen e.g. structural (like a bunion or heel spur), then it is possible to at least slow down the process and possibly prevent this from occurring enough to not let it be a problem in your lifetime.
