A Guide To Prescribing Orthotics For Alpine Skiing
- Volume 17 - Issue 4 - April 2004
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Q: How does one’s skiing level affect pedal mechanics?
A: Beginning skiers tend to lean backward and emphasize heel weighting, according to Dr. Sol. He adds that heel weighted skis allow less stability and the least amount of directional control.
Drs. Schneider and Maurer concur. They say this tendency in novice skiers can lead to difficulty turning and boot-related injuries such as subungual hematoma, dorsal nerve compression and irritation of bony prominences across the metatarsal-cuneiform joints.
More advanced skiers tend to evenly weight and/or forward weight their skis, points out Dr. Sol. He explains that evenly weighted skis provide the most stable support and control over direction.
Drs. Maurer and Schneider say advanced skiers maintain forward pressure of the tibia on the boot cuff. They emphasize that leaning forward and flexing into the boot cuff allows movements from the hips and knees to transfer more quickly into the edge of the ski.
Q: What considerations are unique to the placement and function of an orthotic in a ski boot?
A: When patients are wearing shoes, Dr. Sol says STJ pronation and supination are primarily influenced by the shape of the supporting surface, pedal function and shoe structure. When patients wear ski boots, STJ pronation and supination are “more of a passenger responding to the forces generated by knee function,” according to Dr. Sol.
The usual biomechanical goal with shoes is controlling pedal mechanics. With ski boots, the goal is to control knee function by accommodating pedal function, notes Dr. Sol.
Drs. Maurer and Schneider have developed the semi-rigid Snowthotic, an on-snow device fashioned from a neutral off-weightbearing cast. The doctors say the device is extrinsically posted forefoot (full width) and rearfoot. The Snowthotic incorporates a medial flange and a lateral clip that lock the foot into the boot. Drs. Maurer and Schneider say the device offers an “integrated system,” which responds to direction from above with greater precision and less effort.
They also point out that one can modify the Snowthotic to accommodate specific pathologies, including sesamoiditis and neuroma.
Q: What general guidelines do you recommend when translating a successful walking or jogging orthotic prescription into a skiing orthotic prescription?
A: As a general principle, Dr. Sol increases the flexibility of the orthotic shell when translating an orthotic prescription from shoes to alpine ski boots. He notes you should always evaluate the ski boot before prescribing, fitting and dispensing ski orthotics. To that end, he will remove the liner from its shell to assess fit and examine the shell’s interior.
Dr. Sol says most boot manufacturers include one or more rigid interior soles for width adjustment. He notes that alpine ski boots become more narrow when the skier raises the foot higher in the shell and become wider as the foot lowers in the shell. Therefore, if a boot fits tight without any interior soles, Dr. Sol says adding an orthotic will raise the foot in the shell and make the boot more narrow.
“Controlling orthotic bulk is vital in these cases or, conversely, new ski boots may become necessary,” says Dr. Sol.
Since loose-fitting boots become more narrow with the orthotic, placing rigid interior soles between the bottom of the boot shell and the liner will provide a more snug fit, according to Dr. Sol.
Orthotic impression techniques vary and include in-boot casting, partially weighted foam boxes and standing techniques to align the knee. In the experience of Drs. Maurer and Schneider, the standard neutral position negative cast is effective. They say the goal is to lock the foot into a neutral position within the boot and permit the efficient transfer of hip and knee movements into the ski edges.
With the aforementioned Snowthotic, they note that using an extrinsic, sulcus-length, forefoot post balances any forefoot varus or valgus, and evenly distributes weightbearing pressure across the metatarsal arch. Drs. Schneider and Maurer also point out that you can accommodate the forefoot post with cutouts or balance pads for plantarflexed metatarsals, capsulitis, bursitis and sesamoid pathology.
Dr. Sol founded the Walking Clinic, PC and practices in Colorado Springs, Col. He is a consultant to Tekscan.