Adjusting Orthoses: Simple Solutions To Common Complaints

Larry Huppin, DPM

   These studies indicate that metatarsal pads can be an effective modification to add to a foot orthosis for patients suffering from sub-metatarsal pain, calluses and ulcers. Practitioners can make the addition of metatarsal pads simple by initially prescribing their orthoses and leaving the cover unglued on the anterior portion of the orthosis. This allows placement and modification of the metatarsal pad to ensure patient comfort. Although the study above indicates the general area to place the pad for optimum pressure reduction, there is still a subjective component and the patient will tell you where the pad is most comfortable. Let the patients move the pad (they can tape it in place) until they find the most comfortable placement. Only then should one glue the pad to the orthosis and glue the cover anteriorly.

When Patients Return With New Symptoms

The third category that might require adjustment of their orthoses is patients who develop new symptoms when they begin to wear their orthoses. The most common new symptoms I see are pain affecting the knee, hip and/or back when patients are initially wearing their orthoses. The most common cause seems to be orthoses that we prescribe to reduce excessive pronation but do so in a manner that they apply more supinatory torque then the patient can tolerate.

   Several studies, for example, have demonstrated that valgus wedging of the heel can reduce varus torque within the knee and symptoms associated with medial compartment osteoarthritis.7,8 Conversely, however, varus wedging may act to increase torque in the medial knee and symptoms associated with medial compartment osteoarthritis. Since in most cases a functional orthosis acts as least partially as a varus wedge, there is certainly risk for increasing medial knee pain with the use of functional orthoses.

   The goal when adjusting these orthoses is to decrease the “varus wedge” function. To look at it another way, we want to reduce the supinatory torque that the orthoses are applying around the subtalar joint axis or let the patient pronate a bit more. One of the easier techniques to accomplish this is to increase the flexibility of the devices by grinding them thinner in the arch as I have described above. Other options include removing the rearfoot post and/or adding a valgus extension to the orthosis.

How To Adjust The Orthotic For Shoe Fit

Finally, a skilled orthotic practitioner must be able to adjust for shoe fit. Listed below are a few of many modifications that one can make to allow for improved shoe fit.

   Narrowing the orthosis. One should narrow the orthosis only from the medial aspect. If the clinician narrows the device laterally, this allows the entire orthosis to slide laterally in the shoe and the arch of the orthosis will not match the arch of the foot.

   Lowering the heel cup. Since a heel cup gets wider as it gets higher, the heel cup width is often the limiting factor in allowing an orthosis to fit into the most posterior portion of the shoe. Be aware that after you lower the heel cup, you must often make the posterior wall of the heel cup thinner.

   Thinning the heel contact. If a patient feels that the heel is pistoning out of the shoe, thinning the heel contact point of the orthosis allows the orthosis to sit lower in the shoe and in many shoes will eliminate the pistoning.

In Conclusion

To provide patients with the best orthotic therapy and optimum outcomes, podiatrists must be skilled at adjusting and troubleshooting foot orthoses.

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