Ski Boot Orthotics: Plowing Through The Options

As December arrives, patients who enjoy winter sports begin to think about skiing. Ski boot technology has come a long way in recent years, with many comfort features added to complement the performance the boots are designed to provide. Patients will often ask your opinion as to what they need and how they can enhance their skiing. With this in mind, our expert panelists offer their opinions. Q: What are the most interesting advances now available in ski boots for the upcoming season? A: In the past five years, ski boots have moved in a few directions, according to Ben Wax, CPed. They have become more anatomically designed, providing better fit, which in turn gives skiers better performance and circulation. “Most mid- to high-level boots have a thermal molding liner,” notes Wax. “The liners are heated up and the foam in them expands. The skiers then put their boots on and the liner sets around their feet.” He notes this is a comfort feature and is not a performance enhancement like a foam-injected liner. While custom fit liners are expensive, Michael Schneider, DPM, says they will help accommodate structural problems. He emphasizes “adjustments for bony prominences early on.” Dr. Schneider says he encourages his patients to seek out an experienced boot fitter who is familiar with foot types and boot lasts. Wax says ski boots have become softer and the key is providing skiers with boots they can flex. He points out that the style of skiing is changing with the new shape of ski design and skiers must have forward flex in their boots to steer and balance on their skis while they are accelerating. He says if a boot is too stiff, skiers will constantly be sitting on the back of their skis and losing control. Indeed, Wax says the days of DPMs considering only the stiffest boots for skiing are gone. Wax mentions the new “Soft Boots” by Rossignol, Nordica, Salomon and Dolomite. He says they’re “very soft and comfortable,” although the jury is still out on their performance level. Still, he says they’re probably the best option for novice and intermediate skiers. “You cannot put a low intermediate who skis 15 days a year into an all mountain high performance boot,” says Wax. “They will not have fun. And that is what it is all about.” Women’s ski boots have been given major attention in the past five years, observes Wax. He says these boots are designed to accommodate skiers with narrower heels and higher insteps. Specifically, he notes the upper cuffs of the boots are lower to accommodate the shorter Achilles tendon and lower calf muscles that many women have. He adds that women’s boots are also softer in flex than their male counterparts. Dr. Schneider prescribes his Snowthotic device for all “on snow” sports including alpine, Nordic Telemark skiing along with snowboarding. He says the Snowthotic “is the most precise method of bringing the ground up to the foot which, in my experience, has allowed my patients to have more control with less effort.” Dr. Schneider says since there is no heel-toe dynamic in skiing, his device locks the foot into “neutral” position by using extrinsic rearfoot and forefoot posts along with other modifications of the device. Doing so converts the boot/Snowthotic/foot into an integrated system that responds to action from above, according to Dr. Schneider. Q: Under what conditions would an orthotic be advisable as opposed to canting of the outside of the boot? A: Howard Dananberg, DPM, says that as a general rule, you should manage any deforming component of the legs (i.e. genu varum or valgum) with an external cant on the outer or inner edge of the boot. “Canting outside the boot is a great tool to give the skier a level playing field,” says Wax. Since skiers use both the inside and outside of their skis, Wax says they closely distribute weight to both. As skiers roll their knees across the axis of the ski, they will be transitioning from the medial edge of one ski with the lateral edge of the other ski to the opposite edges, ideally at the same time, notes Wax. He says canting brings the timing of the transition for each leg as close as possible. As for cost considerations, Wax notes canting outside the boot costs about $100 for plates which are added under the bindings. Doing that creates a left and a right ski. For about $150 to $200, you can have the soles of the boots ground and then the boots are built up back to DIN (industry binding and boot standards). However, Wax notes that canting without an orthotic or custom insole to stabilize the interface between the boots and the feet is “useless.” Until you stabilize the foot and ankle in the boot, you can’t get a reliable interpretation of what type of out-of-boot canting will help, notes Wax. Once the foot is stabilized, you can determine the relaxed position of the center of mass of the knee at the tibial plateau, which he says should fall just inside of the center of the axis of the patient’s foot in the ski boot. “Canting outside the boot is great. It really helps but not as much as an orthotic and not without an orthotic. I don’t know any top boot fitters who cant someone without them having a good orthotic in the boot,” emphasizes Wax. Dr. Dananberg says changes to the inside of the boot with a custom foot orthotic are best used to manage the varus relationships of the foot itself, excluding the leg influence. “On a fairly routine basis, I do use first ray cutouts to permit plantarflexion of the first metatarsal (since) controlling the inside edge of the boot against the snow is of major significance,” explains Dr. Dananberg. Dr. Dananberg says when the first metatarsal is posted in varus, it increases the difficulty of first ray plantarflexion and seems to exacerbate control and pain issues. He also advises that you make sure the medial arch of the orthotic is not excessively high. Dr. Dananberg says taking this precaution seems to enhance comfort, particularly during the break-in period. Wax adds that Tecnica Ski Boots have a cuff alignment mechanism (dual pivot adjustment) that actually assists alignment and sometimes negates the need for canting the boot. As Wax points out, most “canting adjustment” mechanisms on ski boots are really geared toward lower leg cuff alignment. He says they are effective in helping the upper cuff follow the shaft of the lower leg, which prevents deflection of the lower leg away from the axis of the boot and ski. Q: What other comfort features would you recommend to enhance the skier’s experience? A: All three panelists mention toe heaters. The heaters use a small disk added to the sock liner or orthotic in the boot, directly under the toes. Combined with a rechargeable battery pack, the heaters can provide an all day heat source. Wax feels rechargeable batteries work the best in boot heaters. Dr. Dananberg says the toe heater feature is “far and away” his favorite and notes that several models are available. Dr. Dananberg and Wax also cite the better wicking materials used for hosiery. When the feet can be kept dry, they feel far less cold. Keep in mind, however, that these materials do wick the moisture to the boot liner, according to Dr. Dananberg. It is important to allow these to dry out at night so as not to put on a wet boot on that next cold winter morning. “While ‘heat’ may not be the right word, they do prevent that ‘freezing’ feeling on even the coldest days,” notes Dr. Dananberg. Dr. Dananberg (pictured) practices in Bedford, N.H. Dr. Schneider has practices in Vail, Aspen, Carbondale and Frisco, Colo. He designed the Snowthotic and formerly owned the South Shore Ski and Sport in Cedarhurst, N.Y. Mr. Wax has been running Inner Bootworks in Stowe, Vt. since 1997. He has been fitting ski boots since the mid-1970s and became a certified pedorthist in 1999.