Biomechanics, Pathologies, Orthoses, Boot Modifications. Jack Hutter DPM, C.ped, FACFAS

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1 Biomechanics, Pathologies, Orthoses, Boot Modifications Jack Hutter DPM, C.ped, FACFAS

2 Boot fitting, just like shoe fitting, is an art and a professional skill in itself, requiring explicit knowledge and years of practical experience to become expert *We as foot care experts always look at fitting shoes from a biomechanical perspective. This the same with a boot fitter, except even more so *We will learn how proper boot fitting leads to increased comfort and performance, whereas the wrong boot will be uncomfortable, provide poor performance, and potentially could cause harm

3 a foot examination is performed foot measurements must be taken considerations are made for mechanical control and pathology accomodation A fitting is performed to assess function

Foot measurements are taken using a metric sizing scale A more thorough leg, knee, and hip examination is necessary in boot fitting due to the fixed nature of the ankle in the boot Greater attention

4 Foot measurements are taken using a metric sizing scale A more thorough leg, knee, and hip examination is necessary in boot fitting due to the fixed nature of the ankle in the boot Greater attention must be directed to foot anatomical variations due to the unforgiving nature of the boot itself The construction of the boot, and performance requirements, demand the need for greater boot adjustability to achieve peak performance Multiple encounters are often necessary to ensure proper boot fit and function

zeppa ),removable, platform between shell and liner, provides boot stability and insulation * Last interior cavity shape * Toe and heel lugs

5 * Liner removable inner boot, various types, provide padding and snug fit * Shell outer boot, two parts, upper cuff and lower shell * Footbed inside the liner, removable platform * Bootboard ( aka. zeppa ),removable, platform between shell and liner, provides boot stability and insulation * Last interior cavity shape * Toe and heel lugs attach the boot to the bindings * Boot shaft interior upper cavity * Cuff removable upper portion of the shell, adjustable to allow shaft/cuff alignment changes * Buckles metal or plastic, three components include the catch, the bail, the lever

* Examine for anatomical pathology - hammer toes; hallux valgus; Tailor bunion; dorsal, medial or posterior areas of bone hypertrophy - edema - toenail dystrophy * With the patient in

6 * Examine for anatomical pathology - hammer toes; hallux valgus; Tailor bunion; dorsal, medial or posterior areas of bone hypertrophy - edema - toenail dystrophy * With the patient in 90/90/90 alignment, frontal plane neutral, examine for - arch structure - stance width - frontal plane pathologies such as FF add/adbuctus, malleolar/tibial torsion, genu varum, genu valgum

* Frontal plane stance, feet in line with hips, examine for patella alignment indicating femoral torsion, genu varum or valgum - tibial torsion malleolar torsion - forefoot add/abductus

7 * Frontal plane stance, feet in line with hips, examine for patella alignment indicating femoral torsion, genu varum or valgum - tibial torsion malleolar torsion - forefoot add/abductus hallux valgus, hammertoe - arch structure, instep height, foot girth * Biomechanical examination - subtalar joint, midtarsal neutral position, resting calcaneal stance position, malleolar torsion

8 These supportive, accomodative and shock absorbing functions must be provided by modifications to and within the boot, or the boot /ski interface

9 *Important measurements to be made are - foot length and width - instep measurement - ankle range of motion - shell fitting *Shoes are designed to transfer foot movement forward, generally in the saggital plane *Ski boots are designed to transfer foot movement outward to the edges, generally in the frontal plane *Shoe sizing measurements are not equal to those of boot sizing; a boot generally fits 1-2 sizes smaller than a shoe

10 *A Brannoch device specific for ski boot measurements is used which has metric calibration *Each ski boot manufacturer may have their own Brannoch device for fitting their particular line of boots

11 *Like shoes, ski boot design is manufacturer specific with many styles to chose from *Like the shoe fitter, the accomplished boot fitter needs to be familiar with all of the different style variations that manufacturers have built into their lines *When fitting, try to match the boot style with the skiers skill level *Racing boots are tightest, have thinner liners, low volume snug shell fit *All mountain / high performance boots have medium tightness and liners are more padded, but fit is still snug *Sport / recreations boots are loosest and most padded, allow for the least amount of control and performance

12 *Length and width - Mondopoint Brannoch device ( note there are some brand specific measuring devices ) - a device used worldwide, units are metric mm = 20 mondopoint ( cm ) - mondopoint measurements are not age or gender specific - unlike shoes, measurement is taken sitting and standing, but the sitting measurement is used for boot sizing to provide a snugger fit - standing measurement, larger of the two feet, indicates amount of foot flexibility and potential need for a foot bed - sitting measurement allows for more toe room, is used for foot bed sizing

13 * Length and width continued- - shoe lasting refers to the entire shoe, whereas ski boot lasting refers to forefoot width - a slight diagonal from the medial aspect of the 1 st metatarsal head to the lateral aspect of the fifth metatarsal head - width is referred to either in mondopoint terms, or narrow average wide - narrow width/last, mm, corresponds to shoe width A, B, indicated for narrow, low volume foot, or racer - average width/last, 100 mm, corresponds to shoe width C, D, indicated for average foot volume and width - wide width/last, mm, corresponds to shoe width E, EE, indicated for wider, higher volume feet, edema

* Instep measurement - refers to the anterior aspect of the ankle and the area around the ankle at this level - very important for proper instep as this helps to hold to stabilize the heel in the

14 * Instep measurement - refers to the anterior aspect of the ankle and the area around the ankle at this level - very important for proper instep as this helps to hold to stabilize the heel in the boot heel cup measurement is taken using the Brannoch device and a metric tape measure - patient stands on Brannoch and measurement is taken from the medial heel around the front of the instep to the lateral heel - compare the instep value to the foot length value if instep length equals foot length, correct instep fit if instep length is higher or lower than foot length, size up or size down one size for proper instep fit

* Ankle range of motion - biomechanical measurement of the amount of ankle dorsiflexion is very important in matching appropriate boot ankle flex to ankle ROM In the classic sense, passive ankle

15 * Ankle range of motion - biomechanical measurement of the amount of ankle dorsiflexion is very important in matching appropriate boot ankle flex to ankle ROM In the classic sense, passive ankle motion is taken non weight bearing with the knee straight and bent - less than + 10 degrees indicates ankle equinus - Knee straight and ankle dorsifexion reduced, either gastrocnemius or soleus equinus, or both - Knee bent, ankle dorsiflexion still reduced, soleus equinus - Knee bent, ankle dorsiflexion above + 10 degrees, gastrocnemius equinus - These measurements are a tip off as to whether there need to be concerned regarding a significant equinus impacting boot fit

* Measuring ankle range of motion - As with foot sizing for boots, ankle ROM sizing for boots is also taken on and off weight bearing - A protactor is used measuring the angle made from a fibula

16 * Measuring ankle range of motion - As with foot sizing for boots, ankle ROM sizing for boots is also taken on and off weight bearing - A protactor is used measuring the angle made from a fibula bisection to the lateral malleolus and the ground - The leg is advanced forward flexing the knee with the heel touching the ground - Measure fibula/malleolus/ground angle at the point when the heel starts to raise from the ground - This measurement indicates the maximum amount of ankle dorsiflexion - This value is compared to the angulation of the boot during fitting Boot adjustments might be necessary if there is less patient ankle dorsiflexion than the boot allows

* Shell fit is the fourth consideration, which involves making sure the foot fits properly in the boot without the liner * This provides a snugger fit when the liner is in the boot * Steps are 1.

17 * Shell fit is the fourth consideration, which involves making sure the foot fits properly in the boot without the liner * This provides a snugger fit when the liner is in the boot * Steps are 1. Remove liner 2. With the larger foot in the boot, slide foot forward until toes touch toe box 3. Using a flashlight observe the distance between the back of the heel and the boot wall 4. A 1 space is roomy, ½ space is considered snug 5. So, 1 for novice, 3/4 for experienced, 1/2 for advanced, competitive skier

18 1.Pain at prominent areas of the foot and ankle 2.Sweaty, cold feet 3.Arch and leg fatigue 4.Numbness, tingling of the feet, toes, 5.Toe jamming, toe cramping 6.Burning pain under the metatarsal area 7.Arch strain 8.Lower back pain 9.Knee pain 10.Poor performance

19 1. Hot spot adjustments 2. Wet boot considerations 3. Boot liners 4. Ankle flex 5. Proper sizing 6. Foot beds, orthotics 7. Cuff adjustment

* 1. Pain at prominent areas of the foot and ankle - Boney prominences become hot spots from boot pressure even if the boot is properly fit - Hallux valgus, Tailor bunion, hammertoes, Haglunds

20 * 1. Pain at prominent areas of the foot and ankle - Boney prominences become hot spots from boot pressure even if the boot is properly fit - Hallux valgus, Tailor bunion, hammertoes, Haglunds deformity, dorsal midtarsal exostosis with or without cavus foot structure, hypermobile flatfoot - THE FIX - Analogous to shoe stretching, heat is applied the area on the boot where the prominence presses, pocketing that area with a pneumatic press - Heat molded, appropriately fitted boot liner - Off the shelf, customized, or custom foot bed - Some boots have pre-molded pockets at medial and lateral malleolus

- Wet boots = wet socks in a closed, nonventilated space = discomfort - Increased moisture leads to skin maceration, a cold sweat, burning feeling - Can exacerbate concurrent pathologies such as

is the problem - Boot closure system, ineffective toe dam, poor boot fit - Various boot dryer systems are also available - Allow for greater boot liner longevity - Reduce bacteria proliferation which

21 - Wet boots = wet socks in a closed, nonventilated space = discomfort - Increased moisture leads to skin maceration, a cold sweat, burning feeling - Can exacerbate concurrent pathologies such as tinea pedis, bromhydrosis - Contributes to premature boot liner breakdown - THE FIX - A pedorthist will usually look at the shoe as the cause of the problem - Similarly, in this case, the boot often is the problem - Boot closure system, ineffective toe dam, poor boot fit - Various boot dryer systems are also available - Allow for greater boot liner longevity - Reduce bacteria proliferation which is the cause of bromhydrosis - Reduce fungal proliferation, alleviating tinea pedis symptoms - Steri-shoe placed in liner and boot for fungicidal and bactericidal effect - Wicking socks to absorb moisture from the skin

* 3. We see that boot liner considerations were helpful in addressing the previous two symptoms of pressure at prominent areas and moisture, coldness - They are also useful in improving performance

22 * 3. We see that boot liner considerations were helpful in addressing the previous two symptoms of pressure at prominent areas and moisture, coldness - They are also useful in improving performance as they provide a snugger fit -Vacuum fit, foam padding within the liner enhancing the foot/liner /boot feels like my own skin effect - liners tend to wear out rapidly, affecting boot fit and thus comfort and performance

4. If boot ankle flex is more than patient ankle flex, patients heel will raise - This causes increased fore foot loading,contributes to burning, metatarsalgia, toe contracture with cramping,

23 4. If boot ankle flex is more than patient ankle flex, patients heel will raise - This causes increased fore foot loading,contributes to burning, metatarsalgia, toe contracture with cramping, Achilles tendon rubbing and strain, Haglunds type symptoms - THE FIX - In the past, boots were very stiff due to high durometer, non flexible plastics. Boot flex now is much more complex, allowing greater flex options due to design and materials - More upright boot flex ( numeric flex rating vague, suggest consider boots in the soft, medium and stiff flex range ) ; stiffer, more upright boot preferred if equinus problems - Heel lifts - Tongue pad to bring the boot to the leg - Upper boot cuff adjustment - reduce power strap tightness - A slight increase in the ski boot ramp angle or reduced forward lean may also reduce Achilles related symptoms

24 * Beginner- intermed intermed-advanced advanced-expert expert-racer soft medium stiff very stiff * Beginner- intermed intermed- advanced advanced-expert expert-racer soft medium stiff very stiff

25 * Remember the four important boot fitting measurements - foot length and width - instep measurement - ankle range of motion - shell fitting * Cuff shape is a consideration that can alleviate calf tightness related pain - select the appropriate cuff height and diameter relative to the calf shape - varies from men to women due to calf size and height - many boots have specific cuff adjustments, especially for women

6. First a discussion comparing foot beds with orthotics - as with shoes, ski boots have stock insole liners designed to be removable to allow replacement with something better - our biomechanical

26 6. First a discussion comparing foot beds with orthotics - as with shoes, ski boots have stock insole liners designed to be removable to allow replacement with something better - our biomechanical examination will confirm the fact that in many cases crucial additional mechanical control is necessary to improve function and alleviate pain - the pedorthist routinely uses orthotics and shoe modifications for this purpose - the boot fitter similarly will use foot beds and boot modifications to provide enhanced performance and comfort Orthotics can be used in ski boots, however there is an argument that foot beds might actually be more effective let s delve into this further

27 * 1. Custom made or pre-fab customized * 2. Full length, shoe size determinant * 3. Multiple density ( durometer ) * 4. Extrinsic and intrinsic posting * 5. Shell modifications ( met pads ) * 6. Deep heel cup to maintain neutral alignment, provide cushioning, reduce side to side rolling * 7. Manufactured using neutral or partial weight bearing produced foot model, negative/positive casting technique, or via neutral or partial weight bearing scanning and router methods * 1. Pre-fab, semicustomized, custom made * 2. Full length, boot size determinant * 3. Multiple density ( durometer ) * 4. Extrinsic and intrinsic posting * 5. Shell modifications * 6. Deep heel cup * 7. Vacuum press, total contact

28 * The characteristics of each are similar with one exception the orthotic casting techniques don t capture an exact interface between the plantar foot surface and the device upper surface * The analogy of the total contact cast used in wound care compared to the foot bed is appropriate both are molded directly to the foot, creating a perfect interface for support, cushion, stability, motion control, off loading, and comfort

* The unique requirements of the foot bed to reduce side to side rolling in an extremely tight environment is much more stringent than that of an orthotic in a shoe * The snug fit of the foot bed

29 * The unique requirements of the foot bed to reduce side to side rolling in an extremely tight environment is much more stringent than that of an orthotic in a shoe * The snug fit of the foot bed accomplishes this, helping to transfer that side to side movement from the foot, through the boot, to the ski This provides better edge control * As with orthotics, elongation of the pronated foot structure is controlled, reducing digital trauma and arch cramping the foot bed accomplishes this more effectively due to the snug, total contact fit * A loose ski boot fit will cause foot slippage, cramping, digital contracture, burning and numbness far greater than that of a loose shoe fit the total contact, snug fit of the foot bed alleviates these symptoms * The foot bed will do nothing to adjust the lateral alignment of the leg with the boot in the frontal plane there must be another important adjustment to consider in this regard

- Since the foot and ankle are rigidly attached to the ski, edging while making turns occurs through knee alignment - To ski comfortably and efficiently, the goal is to achieve KPS ( knee

30 - Since the foot and ankle are rigidly attached to the ski, edging while making turns occurs through knee alignment - To ski comfortably and efficiently, the goal is to achieve KPS ( knee perpendicular to ski ) position 7. Canting is a general term that refers to boot adjustments to allow for this - The inherent outward leg bowing that most patients have doesn t allow for KPS, without forcing the patient skier to compensate - Most better boots are made with the upper cuff of the ski boot independent from the lower boot to allow adjustments to achieve KPS * They are also made with a certain amount of boot shaft angulation to match that of the lower leg. Unfortunately, usually this is not enough angulation to allow KPS alignment, as the leg bowing can vary upwards as much as 7 degrees, while the boot shaft angulation is a most a couple of degrees

* To apply our measurements effectively, we need to delve into the concept of canting deeper * The concept of canting refers to angulation - the cant angle is made by the lower leg and the ski in the

31 * To apply our measurements effectively, we need to delve into the concept of canting deeper * The concept of canting refers to angulation - the cant angle is made by the lower leg and the ski in the frontal plane - as noted above, boots have built in shaft angle canting which usually doesn t match the cant angle of the lower leg * Canting is simply the adjustment made to the boot to realign the cant angle to KPS position * Boot shaft shimming, cuff adjustments and boot sole plates and boot sole grinding are canting methods to achieve this * The pedorthist will view these adjustments as a form of posting, the concept being to move the boot medial or lateral relative to knee and leg angulation to achieve knee perpendicular to ski alignment and ski flat to the ground

* If the patient has more tibial varum than the boot cuff allows ( usually the case ), to alleviate riding on the outer ski edge and achieve parallel ski/ground interface, the patient will move knees

32 * If the patient has more tibial varum than the boot cuff allows ( usually the case ), to alleviate riding on the outer ski edge and achieve parallel ski/ground interface, the patient will move knees closer and feet further apart * The opposite is true with excessive tibial valgum (rare ), with the knees moving further apart and feet closer together * The mismatched boot shaft and leg angulation forces the patient to compensate by realigning their knees to achieve ski flat posture ( bowed or knock knee ) - ski instructors call this the A or H frame alignment - this makes efficient weight transfer from knee to knee extremely difficult when making turns * So the boot canting usually is incorrect for the tibia angulation, thus the desired flat boot/ski/ground interface is achieved by knee and upper leg compensations that contribute to pain, fatigue and poor performance

* Frontal plane examination of the patient weight bearing - observe for femoral torsion, genu valgum/ varum, tibial torsion - most patients will have a certain degree of genu valgum and tibial varum

33 * Frontal plane examination of the patient weight bearing - observe for femoral torsion, genu valgum/ varum, tibial torsion - most patients will have a certain degree of genu valgum and tibial varum * Remove boot liners, place foot bed in boot shell, observe where the lower leg resides in the upper cuff indicating any need for cuff canting * The lower leg should be centered in the boot shaft * This is also a good time to assess malleolar alignment and prominence, ankle and lower leg girth, leg length - boot shaft diameter and height need to match these findings, otherwise there will be painful impingement and rubbing * How do we quantify the amount of canting needed to achieve KPS?

* To determine the type of and amount of canting needed, a KPS cant gauge may be utilized * John Gorman developed this tool to measure the misalignment of any ski boot on any skier * The skier is

34 * To determine the type of and amount of canting needed, a KPS cant gauge may be utilized * John Gorman developed this tool to measure the misalignment of any ski boot on any skier * The skier is standing with boots on, and the gauge determines the position of the center of the knee relative to a line perpendicular to the flat ski * This angle gives the amount of canting needed bring the knee perpendicular to the ski * Most boots are under canted, and the amount of canting needed determines the type of canting * An upper cuff adjustment is considered first -If there is a space on either side indicating the leg is not centered in the boot shaft, adjust the cuff to center the leg, eliminating the extra space * If still not vertical, cuff shimming can be utilized adding padding to the tight side to center the leg * Boot sole plate canting or grinding are the third considerations The goal is to achieve 0 degrees KPS, whereas racers may actually benefit from slight over canting ( a degree or two beyond vertical )

* A pedorthist first approaches ski boot fitting analytically considering biomechanics and anatomy, and then applying hands on lab skills * The pedorthist understands that boot fitting is much more

35 * A pedorthist first approaches ski boot fitting analytically considering biomechanics and anatomy, and then applying hands on lab skills * The pedorthist understands that boot fitting is much more complex than shoe fitting because of the design of the boot, the rigid interface of the boot with the ski, and the motions unique to skiing produced by the ski/terrain interface * Ski boot comfort and performance are directly related to properly taken and applied length, width, instep, ankle flex and shell fit measurements * Of the many useful tools utilized for boot comfort and performance, foot beds and canting are probably the most important

36 Thank You

BIOMECHANICAL EXAMINATION OF THE PEDIATRIC LOWER EXTREMITY

BIOMECHANICAL EXAMINATION OF THE PEDIATRIC LOWER EXTREMITY B.Resseque, D.P.M. ARCH HEIGHT OFF WEIGHTBEARING Evaluate arch height by placing a ruler from the heel to the first metatarsal head Compare arch