INJURY PREVENTION

Addressing or accommodating these biome- chanical deformities can have a very positive effect on the individual’s skiing. Some of these biomechanical deformities can be corrected by physiotherapy or podiatry treat- ment or kinesiology muscle training/person- al training. Once the structure and function of the skier has been assessed and addressed, the next aspect to look at is the interface between the foot and the ski edge – the ski orthotics.

SKI ORTHOTICS AND FOOTBEDS Ski orthotics are generically referred to as footbeds and are provided in most ski shops. There are sev- eral different types on the market today ranging from ‘over the counter devices’ to ‘semi-cus- tom’ or even ‘custom made’ devices. These are often made or supplied by the ski boot fitters in the retail shops and rarely pro- vided by podiatrists.

Footbeds can per-

form an accommodative and/or function- al role in the ski boot. The devices can be used accommodatively to take up volume to prevent dorsal or transverse movement of the foot in the ski boot during skiing or they can be used to change the functioning position of the foot. A footbed can be used in the ‘excessively pronated foot’ to hold the foot in a more supinated position from the resting position of the foot. This will then allow foot pronation to occur during edging of the ski. Without the ski orthotic the foot will not be able to initiate the turn from the foot, as residual pronation is not available from a maximally pronated foot.

The ground reaction forces underneath the foot are significantly less during skiing compared to in the gait cycle. Therefore less pronation control is required in the device. For this reason, skiers should have their walking or running orthotics assessed by their practitioner to determine if they appro- priate for skiing. Very often too much prona- tion control is built into footbeds which interferes with efficient edging mechanics of the foot. It is difficult to assess the function or even effectiveness of footbeds, as feed- back is subjective. What may feel comfort- able to the skier may actually be impeding foot pronation and edging mechanics. As with all lower limb biomechanical deficien- cies, compensations will occur. A clinical assessment method for assessing footbeds is to stand the skier on the footbed barefoot and simulate movement patterns of the foot required for edging the ski. The first move- ment pattern to assess is the fore and aft movements.

This is done by moving the

centre of mass forwards and backwards. If the arch height is too high on the footbed device, simultaneous forefoot and heel

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Figure 3: Standard ski footbed

contact is difficult. The skier will either not be able to achieve simultaneous loading of the forefoot and heel or the arch of the footbed will be very intrusive on the arch of the foot. The next movement pattern is to look at the ‘rolling in’ movement of the foot. To assess this, the skier should stand in sin- gle limb stance with the hips counter-rotat- ed from the loaded limb and roll the foot into gentle foot pronation to simulate edg- ing mechanics. Once the movement pattern is learnt then this is repeated standing on the footbed. The movement pattern will either be harder, easier or the same. If the movement is harder with the footbed than without, then the function of the

device needs to be assessed in more detail. For example the arch height of the

footbed may need to be reduced to allow more pronation to occur. Or it may be that the balance between forefoot and rearfoot pronation control needs to be relocated. If the move- ment is improved then the function of the footbed is adequate.

It should then be decided whether further adjustment to the footbed will encourage even better function. A clinical tool which enables more objective visual biofeedback is assessing the patient using a pressure transducer measurement system. The system I prefer for this is the Novel Pedar System. Once the biomechanical deformities and the footbeds have been addressed, the next aspect to look at is the ski boot itself.

SKI BOOT FITTING The proper fit of the ski boot is as important as its biomechanical design (3). There is a simple concept that should be followed when assessing and fitting ski boots – you must match the shell of the boot to the anatomy of the foot and the performance of the ski boot to the level/ability of the skier. This is so often over-looked and is the cause of most foot pain during skiing. If the skier has a wide forefoot then the type of ski boot chosen for the skier should have a wide shell. In some cases modification to the ski boot is required which involves stretching of the shell using a press or a hydraulic stretch- er. The same goes for the skier with a narrow foot, a narrow lasted boot should be select- ed for the skier and additional padding should be added to the liner dorsally to stop any residual transverse or dorsal movement within the ski boot. If a beginner/interme- diate level skier is fitted with a high perfor- mance stiff race boot it would be difficult for the skier to edge the ski. This is because at that level of ability, the skier has generally not leant how to flex the ankle in the ski boot and therefore the movement pattern would be more difficult to learn. By fitting

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