For a variety of reasons patients will often complain that they feel like they are tiling outward. Two common reasons for this feeling are limb length discrepency compensation and habitual gait change due to pain/dysfunction. I would recommend that some homework is done with these patients prior to casting for orthotics. After your initial history and physical, which should include limb length evaluation, a number of further actions can be considered:
1) Physical therapy
Often times a habitual gait pattern is due to weakness or dysfunctional of a variety of muscle groups in the hips, lower legs or feet. A physical therapy evaluation often identifies an imbalance that has led to a dysfunctional gait pattern. Gait re-training and muscle strengthening often alleviate this feeling of walking inverted.
2) Shoe evaluation/modification
Old shoes are often the culprit behind the inversion. In addition, a combination of a controlling shoe and a controlling orthotic, may lead to over load on the lateral column.
3) Valgus wedge
An application of a valgus extension from heel to toe, on either a previous orthotic or a shoe insole, may help rebalance the patient. This addition can be adjusted for thickness and width. When ordering orthotics this would translate to either a Reverse Morton's Extension, or a valgus forefoot wedge.
4) Heel lift
If an limb length discrepency is present, addition of a lift on the shorter side, may discourage the foot/ankle complex from supinating to increase length of that limb. It may be helpful to dispense 3-4 1/8" lifts and ask the patient to increase their heel height every 5-7 days until they feel more even. If this is a chronic issue, the time span may be longer.
5) Cast for orthotics
Once your corrections have been confirmed as improving function, just translate your temporary additions to an orthoitc prescription to provide long term relief from this dysfunctional problem.