Shoe analysis

Introduction

Inferior or incorrect shoes can be directly linked to many problems beyond immediate foot and exercise discomforts: the lower legs, knees, hips, the lower back and even further up the spine have been shown to be adversely affected.
The last decade has seen many improvements both in the characteristics and quality of the athletics shoe. The walking shoe has also been developed.
Exercisers and athletes have much to gain from getting the best possible shoes on their feet. There are now many examples of how both leg pain and the inability to run longer distances have been cured by using basic shoe information. A good athlete can become even better with the correct choice of shoes.
Over recent years, ambitious analyses of exercise shoes have been carried out, providing those of us who work with problem-feet a better basis for our diagnoses, and a method of treatment for both shoe customers and patients.
For those plagued by chronic foot or jogging-related problems, this has meant a vast improvement in their chances for seeing an end to their discomfort.
From our daily contact with customers and patients over the last years, we have marked an obvious need for better information regarding both exercise and walking shoes.

In the following chapter, we will present in a concise manner our rationale when analyzing feet and shoes, as well as the advice we share with those we meet in our daily work.
It is our hope that this information will lead to both increased consideration and open discussion in shoe stores, schools, and in healthcare, as well as providing the consumer with a better understanding upon which to base a choice when confronted with the vast selection of shoes available today.
This chapter on shoe analysis was written in cooperation with Lars Höglund, Orthopedics Engineer.

What characteristics should a good shoe have?
There can never be an exact answer to the above question. Mankind has utilized foot-protection since the Stone Age, but tastes and practicality have varied down through the ages for many reasons.
Moreover, feet are in themselves varied and highly individual, demanding differing shoe characteristics depending on the wearer. A foot can be large, petit, wide, narrow, high, flat or deformed in differing ways. We all know that even those with an identical shoe size seldom agree that the same shoe fits comfortably.
Both historically, and even today, the shoe's usage has been the dominating factor in its' design.








 

A boot must protect against water, but a trekking boot must also support the foot to hinder movement and ensuing blisters. A hunting boot, in our latitudes, must insulate against the cold while the hunter stands still in the forest and thus some support must be sacrificed to ensure there is enough space around the foot for heavy socks - for that important insulating layer of air. In the Wild West the boot was designed for use in the saddle and as protection against snakebite, an almost impossible design for walking longer distances, but for its' specific purpose the boot was highly functional.
Clearly, ski boots or high-heeled dancing shoes would be as poor a choice for an Indian as moccasins are for a factory-worker. American Indians used moccasins enabling silent movement in nature, an essential when approaching game closely enough to use Stone Age weapons. Wooden clogs are excellent to slide into, to fetch the newspaper or wood from the basement, but equally worthless for long walks, for standing long hours in, or for jogging. My view that children should not use wooden clogs may be qualified: since children often run, such footwear should only be allowed as an exception and then only for shorter periods.


"Illustration from "Attack on the Colonials" by E.S. Ellis 1937.
Permission: B.Wahlström Pub.".

A shoe or boot's usage most often determines its' shape or style. However the footwear's inner construction and suitability for the foot, based on foot anatomy and function is most critical and is what the latter part of this chapter is all about. But first, we will concentrate on the walking- and jogging shoes and their characteristics.

What constitutes a good walking shoe?
Unfortunately, too many shoe stores are primarily interested in sales figures, and lack basic insight into what they are selling. Both the larger, but even the smaller, more specialized ones sadly fall into this category. Even the presence of a joggers' treadmill in a store is not automatically a sign that the personnel have been trained to know what to look for when it is put to use!
Keep in mind that neither the expensive price nor the latest design, are any guarantee that the shoes are "best": famous brands do not always ensure highest quality!

In our opinion, there are a few simple points to observe when buying shoes - for you and for your children:
1. The uppers should be of a light material which breathes and sheds water, tolerating limited autumn rains / wet snow (Summer shoes may vary on this point)
2.The tongue should be soft/padded to protect against the pressure from laces and knots.
3. The laces must allow for individual adjustment depending on your needs, but a snug fit over the instep is particularly important.
4. The shoes' heel support / heel cap should be soft and stable, preventing vertical or horizontal heel movement.
5. A non-skid, removable inner sole is a plus, as it will increase the shoe's grip on your foot, preventing it from sliding around in the shoe.
6. The arch support should be able to be altered or exchanged: both the longitudinal and frontal arch supports should be able to be individualized if necessary.

 

7. Space for your toes: your toes need room to work and breathe!
During normal walking your foot both spreads out and lengthens up to one centimeter (1/2 inch) in each direction. Ensure that the shoe gives you the space you need - as well as some airspace above your toes.
8. The shoe's outer sole should have a non-skid pattern and enough insulation against the cold. The sole must suit your body weight and the terrain the shoe will be used in.
9. The forward end of the sole must be soft and must flex where your foot flexes. It should also resist longitudinal torsion.
10. The shoe's heel must be neither too wide (approx 7 cm for adults - 2 ¾ in), nor too low (1.5 cm is adequate - 3/5 in). A heel which is too soft will lessen its' important shock absorbing function and a beveled trailing edge is preferable. A heel that is exceedingly soft, may cause muscle ache in the shin.
11. A number of shoe manufacturers offer the same model of shoe in differing widths.

Many running shoes can be found in two widths (men's and women's), but there are also quality brands offering as many as seven different width sizes (4 men's, 3 women's), which increases your chances of finding shoes that will truly fit. Note that not all shoe stores are either aware of the selection available, or have bothered to stock more than a few of the basic widths in each model!
12. Finally
Don't use shoes that are too worn-down, as these have often lost some of their basic functions.
We are all concerned for our children's well being. In conclusion, I want to underline the following to parents and trainers who are reading these lines: Invest in good, functional shoes following the principles in this chapter, even if such shoes might cost a little more (keeping in mind that price does not always guarantee quality/function). Save some money on slightly cheaper (or used) slalom skis, bicycles or athletic clothes and instead, invest in functional tennis shoes, skates, ski boots or shoes that guarantee comfort.

 

1. Weather resistant, breathable uppers.
2. Soft tongue.
3. Shoelaces
4. Sturdy heel cap / heel support.
5. Ruff patterned inner sole.
6. Interchangeable inner sole.

7. Generous toe space.
8. Nonskid insulated outer sole.
9. Torsion-resistant sole.
10. Shock absorbing, beveled heel.
11. Differing shoe widths.


"Example of a good walking shoe"

Criteria for a good jogging shoe
In principle, the same advice and rules as for good walking shoes will apply here, but for highly specialized sports or extreme running conditions, certain demands will dominate. Football or soccer shoes with spikes will obviously make them unsuitable as running shoes on asphalt.
Boxing shoes, for example, need less shock absorption since the ring mat is soft, and the lighter weight to aid against fatigue, but a boxer must of course use proper running shoes when running his "road miles"! Likewise, for orienteering on the softer forest floor, the orienteering shoe need not have such a thick, shock-absorbing heel, but for better balance and grip in uneven terrain, the shoes require less stiffness and torsion-resistance in their sole!
Tennis shoes often lack a beveled heel to maximize lateral stability during the innumerable sliding and shuffling steps taken in all directions during the course of a match. This very same high-quality tennis shoe can well prove inferior for running on a track!
The running shoe's shock absorption characteristics in their sole / heel must be chosen according to both the body weight of the user and the character of the track.

A runner, who switches from an indoor track to an outdoor asphalt track, should do so with care, increasing his duration on the asphalt in stages while carefully assessing the nature of his shoes' heels and soles. Incorrect or poor shock absorption or too soft a sole may result in foot or leg injuries.
A shoe that a lightweight runner may use to his advantage on a hard surface (i.e. a super-light competition shoe) may very well prove impossible for a heavier runner on the same track. In order for a shoe salesman to give you truly good advice and recommend the correct shoe for a planned activity, he must be completely familiar with a shoe's qualities and those tests that have been performed on it. A shoe that performs well on the surface of a standard treadmill is not necessarily suitable for orienteering or marathon running! Moreover, the shoe's material and the foot's structure can tire or weaken after a period of running. Due to fatigue the angle of the foot's joints may even have changed. Having the customer first run a few miles before performing video analysis may prove advantageous.

 

1. Weather resistant, breathable uppers.
2. Soft tongue.
3. Shoelaces.
4. Sturdy heel cap / heel support.
5. Ruff patterned inner sole.
6. Interchangeable inner sole.

7. Generous toe space.
8. Non-skid insulated outer sole.
9. Torsion-resistant sole.
10. Shock absorbing, beveled heel.
11. Differing shoe widths.

 


Example of a good jogging / athletics shoe


The anatomy of the foot with its' many joints is complex. For the benefit of shoe customers we present a synopsis of the mechanics of the foot's movements in order to properly illustrate the basis of shoe construction.
The foot's movements during the most common running style begin with the heel contacting the ground, when the weight will immediately shift forward, rolling along the bottom and then unto the ball of the foot, to finally reach the big toe.
Neutral runner Pronator Supinator
"Pressure curves along the sole of the foot"

During each step, the sole of the foot is subjected to forces, which, moving forward from the heel and along the sole, will take differing paths depending upon the type of foot as illustrated above. Shoes need to be strengthened in those areas where greatest stress occurs. These areas will vary with the type of foot and style of running.

The movements of the foot: terminology
Over the last years, runners have developed a terminology where the terms "pronation" and "supination" have been freely used to describe the movements shown in the drawing below.
This popular usage, however, attempts to describe the compound movements of several joints around several axes. According to the above usage, "pronation" consists of all of the following components:

1. Upward flexing (dorsal flexing) of the ankle joint 2. Outward angling (eversion) of the heel
3. Abduction (outward movement of the forefoot) of the foot during the inward rotation of the lower leg (tibia)
4. Rotation of the forefoot through the foot's longitudinal axis where the outer portion of the forefoot on the side of the little-toe moves relatively upwards (true pronation).
"Supination" is here the very opposite of the above "pronation".
Biomechanical medicine restricts the terms pronation and supination to describe movements of the fore- and mid-foot only, i.e. Exclusively the movement described above in #4.
The heel has its' own unique and distinct movements called inversion (an inward tilting) and eversion (an outward tilting) which should never be included in the above terms
Therefore, the common usage of the terms pronation and supination by runners and by those magazines dedicated to running/athletics has been incorrect where applied to the eversion- and inversion-movements as measured on the treadmill via video analysis. The movements of the heel and of the forefoot occur around completely different axes and must never be confused!

Some important axes of movement of the foot
a) Metatarsal break
b) Transverse axis
c) Oblique axis
d) Longitudinal axis

The heel's movements (in- and eversion) occur around the oblique axis.
The forefoot's movements (pro- and supination) occur around the longitudinal axis.


In actuality pronation and supination are terms that describe exclusively the movements of the forefoot, while in- and eversion describe only movements of the heel (movements of the subtalar joints).

During the mid-phase of the step (weight-bearing phase), the forefoot most commonly pronates while the heel tilts outwards (eversion).
This fact has lead to confusion around these terms and resulted in incorrect measurement results. Measuring the heel's angle from behind (relative to the lower leg's axis) to determine a pro- / supination angle is incorrect methodology. This type of measurement most often fails to reflect the true situation - a problem we will return to in the following pages.
An outward tilting of the heel will naturally affect the forefoot's position (likewise an inward tilting) - irrespective of whether the foot is suspended or on the ground.
The forefoot can be held quite still in its' longitudinal axis (no pronation) while the heel is simultaneously tilted outwards (eversion). Test it yourself, with your foot in the air!
Just because the heel is tilted outwards, it does not automatically mean that there is a pronation or any movement around the forefoot's longitudinal axis. That this actually occurs is something we discuss further on.
Note!
The concurrence of the heel's outward movement (eversion) and the forefoot's pronation will often lead to a collapse of the inner (medial) midsection of the foot while bearing weight. Among other effects, the inner ankle will fall and the longitudinal arch will be compressed.
Note!
Modifying shoes in the forefoot, or orthotics with corrective measures in the forefoot treat pro- and supination. In- and eversion are alleviated by corrections in the shoe's heel, or by corrections built into the heel-portion of the orthotic. A shoe with enough stability in its' heel to rectify the foot's misaligned heel angle need not necessarily give the same excellent result to the forefoot. Clearly, both the customer and the person carrying out the foot analysis can be deceived by past methods of measurement and the confusing terminology in use.



Details measurement techniques

Until recently, among runners, this has been the method of measuring pro- and supination. Right foot seen from behind.

Since the forefoot's pronation and the heel's eversion often combine to cause an outward deviation in the foot, this measurement technique may be used for rough corrections.
However we do suggest that you immediately adopt the use of correct terminology when referring to the heel's movements: i.e. inversion and eversion!
Regarding the term "underpronation": 0-7 degrees of pronation = eversion, measured at the heel). This term is also in our opinion imprecise, being equivalent to 0-7 deg. of eversion, a normally occurring phenomenon.
All outward obliquity in the heel should be termed eversion, while all inward movement inversion. However this method of measurement does not reveal all deviations, but instead must be supplemented by other aspects. For example, with knock-kneed or bow-legged conditions, both in- and eversion will vary quite substantially. The above method of measurement on a bow-legged person will reveal obvious pronation, while the foot itself may very well be relatively straight, i.e. no actual deviation in the heel.
When considering a deviant heel angle, it is also highly important to check the angle of the heel of the shoe for deviation, regardless of the customer/patient's other physical problems.

The shoe itself may be crooked in its' entirety or compressed/crooked in the heel. In persons with such physical problems, the deviation in the shoes' heels must first be corrected until the shoe is straight, regardless of the degree of eversion present.

"Bow-legged condition with an uncorrected and corrected shoe, respectively. Note that the angle between the heel and the lower leg should seldom be corrected, as this is the natural position for these persons."
One can often observe inversion in the heel at the moment of impact, switching immediately over to eversion when weight shifts forward in the foot during the mid-phase of the step.
An instant later in the mid-phase, when the forefoot carries the weight, one can often detect a momentary deviation occurring here as well. This leads to an added increase in eversion coinciding with a "fall" of the inner ankle and an observed inward "collapse" of the mid-foot (actual forefoot pronation). This forefoot pronation can be missed if the observer only measures one position of the mid-phase. It is critical to analyze the step during all its' weight-bearing phases!
Moreover, the heel can often show measurable eversion, both earlier and later in the mid-phase, without any ensuing "collapse" suddenly occurring (as described above). Diagnosed as a simple heel eversion lacking any forefoot pronation, it would require a shoe correctly stabilized on the inside close to the heel, but with no correction in the forefoot area. Never confuse heel eversion with pronation of the forefoot!
Some shoes are better at correcting heel deviations, while others do better correcting forefoot movements. Shoes used for pronation/eversion corrections are built up placing "Pronation wedges" of varying lengths in the inner (medial) part of the sole. The shorter wedge generally corrects only heel deviations, while the longer wedges can correct the forefoot as well.

"Pronation wedges of differing lengths"

Phases of the step
The weight-bearing phases of the step can be divided into:
1) Heel impact phase (contact-phase)
2) Support phase (mid-phase)
3) Propulsion phase
At the time of impact the foot is angled upwards (dorsally flexed) with its' sole at an approx. 15 degree angle to the ground for maximum stability.
Commonly, the heel is also angled inwards (inversion) at the moment of contact with the underside of the heel also at approx. 15 degrees. At higher running speeds the heel's inward angle often increases somewhat and the angle between its' underside and the ground can be as much as 35 degrees.
Particularly at high speed it is often that the entire outside of the sole impacts simultaneously. Directly after impact, when weight is increasingly borne, the heel will successively angle outwards without any apparent movement in the forefoot (at this instant, the forefoot is bearing no weight - thus no pronation/supination).

In the support phase the forefoot now comes in contact with the ground. Early in the support phase the lower leg rotates inwards, which normally sees the heel deviating somewhat outwards (eversion). In the mid-support phase, the heel most often continues its' outward deviation, while the forefoot pronates successively in relation to the rate it takes over the load.

However there is no rule to this. Other movements occur which are difficult to detect if one is not observant during video analysis!
Note!
Since the heel often angles outwards early in the support phase, you can detect the forefoot's pronation-movement when the foot's midsection "collapses" and the inner ankle "drops" in unison. At this moment the shoe deviates in the heel area due to its' load in the mid-support phase.
This "collapse" is due not to the heel's collapse, but rather to a collapse in the mid-foot during forefoot pronation. During this support phase it is not sufficient to solely analyze the angle of the heel relative to the axis of the lower leg.
Any movements in the forefoot must also be considered as described above will be obvious to the observer that during this phase the knee's movements are to the greatest degree affected by the foot's attitude, especially if abnormalities (pronation/supination) are present.
Throughout the support phase the knee and lower leg are pressed forward, while the foot is flexed upwards (dorsal flexing) and the lower leg rotates inwards. By the end of the support phase a downward bending in the ankle joint takes place (plantar flexing). This causes an inward tilting in the heel and raises the longitudinal foot arch. The arch is strengthened from the upward bending of the toes, the beginning of the propulsion phase. Immediately before the foot is lifted from the ground, the toes - especially the big toe - bend downwards during the propulsion phase.
At the completion of the propulsion phase the step will end on the inside of the shoe with pronation.

But on the outside of the shoe when supination is present.


"The propulsion phase showing the heel angled somewhat inwards: a common running style."
This complex but natural mechanism is common (about 75% of all have a pronation/eversion). Mal-positioning of the foot due to supination/inversion is less common (5-8%), but no less important to the individual! Runners with neutral foot placement comprise 10-15% of the whole.
In principle, a shoe should be constructed to counteract those deviations that do not follow the normal patterns described above. The ankle joint and softer parts of the foot are exposed to enormous pressures during neutral foot placement. When the foot is misaligned these pressures increase dramatically. This can lead to pain in the foot, lower leg, knee, and even higher up. In extreme cases it can make running impossible for the individual in question. These foot problems can often be immediately corrected with the proper choice of shoes, provided the examiner knows the shoes' differing characteristics and can identify the particular deviations. In some cases, individually tested orthotics is necessary to attain correct foot movements.

The Shoe's Heel


1. If the heel of the shoe extends backwards too much or if it is too hard, the shin muscles can be overworked from having to break the foot before it makes full contact with the ground. This causes strain, leading to aches and pain.

2. One solution is a beveled trailing edge on the shoe's heel, allowing the foot to roll forward in its' step, softening the movement. Less muscle strain means less discomfort. Another solution, which can give the same effect, is a softer, shock-absorbing heel material in this trailing edge.
3. If the heel is too high, it causes a backward bending (extension) in the small of the back, possibly causing pain here or further up in the neck.
4. Heels that are excessively low or too hard may produce calf-muscle pain.
5.The so-called "earth-shoe" design with the negative heel stretches the calf muscles. The foot may be very stable in this attitude, but we see no advantage in this design as the joints in the foot are forced to work close to their limits of tolerance. The probability is high that this attitude will tire out the foot's structures culminating in pain.
Sprinters train using shoes with a normal heel. For competition, long jumpers and sprinters use shoes with very low heels to get a few percent extra powers and thereby a better result. A sprinter should not use these shoes for longer distance running, but rather normal jogging shoes.

Long distance runners should use shoes with approx. 1-1,5 cm (1/2 inch) heels.

Importance of Heel Width
"Greater transverse
torsion" 		"Less transverse
torsion"

6. Heel width on shoes for a normal runner should not exceed 7 - 8 cm. A normal heel width is better than wider ones, which can greatly strain the inner leg muscles when they strive to alleviate the transverse torsion at the moment of impact with the ground. To counteract an incorrect impact angle, the heel can be narrowed/widened differently per side. For correction of inversion, the heel should be widened or hardened on its' outer edge, while for eversion the converse would apply.
7. The heel's degree of hardness and shock absorption is of great importance to the comfort of the shoe while running. A heavy person or hard track surfaces requires a better degree of shock absorption. A good shoe should not, at the moment of impact, allow the heel to tilt excessively inwards or outwards but should remain somewhat straight. In the case of shoes specifically for moderate running speeds, a slight inward tilt is allowable.

Many shoes are too soft in the heel's outer edge. At the moment of impact, the heel material is overly compressed, leading to problems due to unacceptable inward tilting / deviations in the heel angle. Old shoes, with worn-down soles or uppers can often cause this same problem.

Note! This problem in a shoe can be almost impossible to detect without video analysis. There are many different heel designs available to optimize weight distribution in this area of the shoe. The air-pillow design is currently available from different manufacturers, but all do not guarantee optimal results - in many cases, quite the contrary! There are other excellent designs as well! An analysis of each runner's steps when using a specific shoe is clearly critical.

The Heel Cap



The heel cap's function is to hold the heel still and in place. It should be stable and constructed to absorb shock / hinder torsion movements injurious to the foot.

The Shoe Sole
The sole's construction and function varies with the use for which the shoe was designed - both in respect to athletic shoes and everyday shoes / boots. Slalom- and climbing boots have special requirements regarding stiffness and insulation. Winter shoes /winter training shoes must have soles insulated against the cold ground. The sole's tread must be efficient for running on slippery surfaces. Heavy individuals, and those with extremely high arches, need shoe soles with greater shock absorption in order to run in comfort. The sole must be rather soft and able to bend at approx. 1/4 of the sole's length from the toe - where the foot bends. A test for this can be done at home or at the store, using common bathroom scales: pressing the toe portion of the sole on the scales at approx. a 30 degree angle should not require more than a 5 kg (11 lb) pressure to bend the shoe. Competition shoes may be even softer than this, but shock absorption must never be compromised!


"A shoe must not bend in the middle: the foot does not bend naturally here."

The sole must resist torsion to discourage pronation/supination in the forefoot- of great importance on hard and level surfaces, of lesser import in the forest / for orienteering.
" Example of a poor shoe, lacking torsion-resistance"

Besides resisting torsion, the sole may also be required to resist a tendency for pronation or supination, which some may feel are same problem. However, these tendencies not only vary from one person to the next, they also may vary between an individual's left and right foot. This requires that shoe designs must be available in several size variations, or, that the manufacturer can provide special "(anti) pronation / (anti) supination" models. To further complicate the situation, both the heel and the forefoot may be angled in different directions, with the right and left foot commonly differing somewhat.

 

Arches of the foot
A sole must also be individually adjustable for both the foot's longitudinal and transverse arches.
"The foot both widens and lengthens approx. 1 cm under load."

Simple, inlays to help support the longitudinal arch, as well as arch supports for the transverse arch, which (Note) have no effect on pro-/supination tendencies, are normally available in better shoe stores. Such inlays or arch supports, augmented, for example, with a good (anti) pronation shoe, may be of great help to persons experiencing discomfort while running especially those with high arches.
Important to remember is that both the foot's longitudinal and transverse arches are somewhat compressed when bearing weight (compared to while at rest), causing the feet to both widen and lengthen approx 1 cm (1/2 in.). It is critical that the shoes allow for this "expansion".
Simple, over-the-counter arch supports for the longitudinal arch are easy to apply correctly, but the smaller supports for the transverse arch are often placed incorrectly. Care should be taken that these are not placed too far forward in the shoes, but rather, further back than one would believe necessary, assuring that the forefoot's long metatarsal bones can maintain their transverse, bridge-like arch. Do choose a shoe with generous room for your toes!

Correctly placed transverse arch support


Different types of feet demand differing lasts.

Cavus foot (very high arch) requires a curved last. A flat foot needs a straight last.
Inlays vs. orthotics
Inlays are normally made of metal, plastic or leather and are comparatively hard, correcting only the mid-foot and in a few cases, deviant heel angles.
Orthotics are made of a soft material, correcting the entire foot including the forefoot. Generally, orthotics are the most preferable. Orthotics can be made by an orthopedics engineer / technician. Ideally, these orthotics can treat all the previously mentioned ailments, as well as help measurably even in standard athletic shoes, walking shoes and boots. Even high-quality (anti) pronation shoes may need the addition of orthotics to help straighten up the feet. In some cases, one shoe may compensate enough, while the other might need added compensation. Forefoot pronation and deviant heel angles may demand individual correction: what better solution than orthotics specially cast for each foot? Testing for orthotics can be done using different techniques. Traditionally, the standard method has been to take an individual impression of each foot by having the patient/customer stand in a casting box. The mold is then used to make an orthotic. Experience is required to finish the orthotic and testing them in the actual shoes is essential. There are both advantages and disadvantages to this method. One disadvantage is that this mold actually reflects the foot in a state of collapse, while bearing weight.

 


Another method is the "mirror-box" - where the foot's position and contact surfaces can be studied from below, through a sheet of plexi-glass upon which the patient stands. The angled mirror again only allows for a static analysis while the foot is bearing weight. Abnormal pressure points - the ones which "turn white" - are those that must be corrected for. Among those commonly seen are the ends of the long metatarsal bones in the forefoot.
Still another method is analyzing the foot while in motion by following marks placed on different parts of the foot. Movements in the foot are studied with the help of camera, stroboscope or even the naked eye.
If no video camera is available one can stand the patient with the feet slightly apart. Making a "V-sign" with his fingers, the examiner places each finger against the inner anklebones (medial maleolas). The patient then moves his knees straightforward, allowing the examiner to see/feel any inward movement in the anklebone and to what extent. For example, if one ankle "falls inwards", this would indicate pronation/eversion in that foot.


"The examiner's "V-sign" with fingertips placed against the inner ankle bones."


"When the patient bends his knees forward, one or both ankle bones move inwards, indicating differing degrees of pronation/eversion." While the knees are bent forward, observations must be taken of any pronation tendencies, any movement inwards ("fall") of the inner anklebones, as well as studying the angles of the heel tendons (Achilles tendon) from behind. If the Achilles tendon below the anklebone tilts outwards, pronation/eversion may be suspected.

 


" Patient standing with straight legs"

"This patient (standing with knees slightly bent forward) shows a particular tendency for pronation/eversion in the right leg, but also in the other leg"

Casting the Foot at Rest
During recent years a method of foot analysis has been developed using a combination of foot casts, video analysis of the foot - both walking and running on a treadmill, with and without orthotics.
Practical tests of this method have been conducted over recent years and in our opinion the method offers clear advantages. The cast is taken while the foot bears no weight – i.e. "at rest", a condition when pain is seldom reported. "At rest", the elevated foot is "au natural" in its' shape and is uninfluenced by any contact with the floor / weight-bearing pressure, assuring as true a copy of the foot-sole as possible. This technique requires that the big toe be bent somewhat upwards while the cast is taken, to compensate for the increased arching in the foot's longitudinal arch during the propulsion phase

(I.e. when the big toe's tendon is stretched due to the big toe's upward angle).

"Casting with the patient lying prone"

This cast can provide the basis for an extremely comfortable orthotic. The finished cast may be used to correct deviations in the heel, arches or problems in the mid- and forefoot. Upon completion of the orthotic prototype, the orthotic can then be tested and augmented by information gathered from analysis of the slow-motion / stop-action video recording, until pronation /supination problems are treated. After orthotic testing by the patient, video analysis is again performed and final adjustments are made. Subsequent to a trial period of a few weeks, the patient may need a last video analysis and adjustment.
In our opinion, this method is superior to all others because: a) The orthotic mirrors the sole of the foot while in its' most comfortable state b) Video analysis allows exact diagnosis of the mechanics of the foot's movements and deviations. With the new orthotic in the shoe one receives direct feedback from the patient together with visual proof via video, both walking and running. Note that video analysis must be done while the shoes are used for that activity for which they were purchased (i.e daily walking, standing, jogging or running), because the final shape of the orthotic may greatly vary depending on their use. Many activities place different weight-bearing demands, requiring specific corrections. The same runner can often have different degrees of pro-/supination when running at differing speeds.

 

For example, the runner who seems to pronate at jogging speed may well exhibit a "normal" step at higher speeds (increased speed as a rule causes more supination). This runner should not use  (anti) pronation shoes for running at high speed! If the treadmill has insufficient speed while video filming, this problem can easily be overlooked. It is therefore critical to always base the video analysis and testing on the type of activity for which the shoes will be used!


"Runner with increased pronation (uncorrected)"



"Runner with increased pronation/eversion (uncorrected), using poor running shoes. Left photo: while running. Right photo: while walking"


"Runner with increased pronation/eversion (corrected) by (anti) pronation shoe and orthotic"

Obviously, the above method of casting orthotics may be used to great advantage even when treating non-runners such as rheumatics, diabetics, or anyone with foot discomfort while standing, walking, or jogging.

The Worn Shoe
With age and wear, the shoe loses many of its' original design characteristics. All new shoes must be given some time to adjust to the wearer's feet. A shoe manufacturer cannot produce shoes to exactly fit every type of foot, even by offering many different widths / lasts. However, after the "breaking-in" period, the shoes should hold up for an acceptable time for the type of activity for which they were purchased. On average, the modern running shoe holds a very good quality in regards to wear. Shoe companies have invested much time and resources developing good running shoes. There is a vast difference between the modern running shoe and those we used 20 years ago. Such great progress has been achieved, that an expensive, highest-quality shoe on sale a few years ago, can often be overshadowed by a cheaper one today. Do not be fooled by appearances. A flashy, colorful design, a dramatic, attractive "creation" and even a high price tag, can often hide faulty construction and characteristics that are far less than satisfactory.

 

Shoes wear out in different ways: visible wear, and inner fatigue.

Visible Wear
Visible wear is easy to detect and its' causes are usually obvious. Most of us also recognize that badly worn heels or broken heel caps have seriously changed the shoes' characteristics and their comfort to the feet. Don't be too frugal when buying new shoes for yourself or your children! We feel that many compromise on quality when buying children's shoes because they tend to wear out so quickly! It might prove expensive to buy kid's shoes twice a season, but we believe it a good investment in their comfort and as an insurance against future foot-problems. Save instead by buying less candy or a used bicycle instead of a new one. By economizing on luxury items (i.e. alcohol, tobacco, etc) or by bicycling, instead of driving to work. These savings can be used on your children's feet or even your own! The point to this sermon is, that it is in fact possible to realize priorities! Worn shoes should always be replaced by new ones and seldom reused as hand-me-downs. Shoes wear out at differing rates, depending on their use and on their owner. Long distance runners often see wear occurring on the outside of the heel (where contact is first made with the ground) and on the inside edge of the forefoot (from the propulsion phase). Higher running speeds cause increased wear, further forward on the sole.

"Pronation increases wear on the inner sole, while supination wears down the outside."
When shoe soles wear down, the feet bear weight incorrectly and the shoes' shock absorption, torsion-resistance and stability degrade.

This may result in for instance a twisted ankle or that the natural forward "roll" in the footstep is imbalanced, causing pain / discomfort.

Structural Fatigue
Fatigue in the shoe's structure is considerably more difficult to detect, i.e. degenerated shock absorption in a running shoe. The heel need not be especially worn or compressed to the naked eye, but may well have lost much of its' stiffness and elasticity. The best method of detecting this is by video analysis on a treadmill. Some shoes will need a 20 minute run outdoors, as their heels can maintain a short-term stiffness before exhibiting a "collapse". Note that this problem can even occur in new shoes!



One way to see if a heel is wearing out is by measurement. If the heel is 3-4 mm lower on one side than on the other, the shoes are probably worn out.

A final comment on shoes
Much, obviously, has happened in the jogging shoe industry over recent years. There is no question that this trend will surely continue. To be able to find yourself the optimal shoe, basic information is required to properly choose the one model over another. The perfect shoe for all activities simply doesn't exist. A dedicated, experienced salesman can point you in the right direction, but only you can know if the shoe fits! Before buying shoes you should be able to test them indoors, on a treadmill or in a gymnasium, to get the feel of them. This, then, should be a reasonable demand in lieu of video analysis on a treadmill. A shoe store, which does not offer this service, may well lose customers for many years ahead.

 

Go to another shoe store! A service-minded shoe salesman with the education described above, has a decided sales advantage. Customer satisfaction, translates into future sales over the years. Finally: Don't be blinded by designer labels or price tags. Those expensive shoes may well have been designed with characteristics that in no way fit your needs! Famous companies known for good products also issue cheaper variations on the market (i.e. shoes with poor quality, shock absorption and stability). Choose a shoe based on information and a critical eye as to its' quality and characteristics. Most important is that the shoe truly fits both you, and the specific activity for which they are purchased.

Shoe Tests
The results of various running shoe tests have begun to appear, a highly commendable development. These publications can be a great help to many consumers as the choice of shoes can be a difficult one. Keep in mind the following when you read these tests:
* Read the introduction describing the background of each test with care!
* It is critical that you know which category of running style you belong to and what foot deviations you have.
* The choice of shoe last will depend on what type of arches and foot width you have. Your weight is also a critical consideration.

* The shoe with the best test result may not be the best for you!
* A shoe with a lower ranking ("poorer characteristics") may be the best choice if they fit you properly.
* Be aware that test results can differ - on the same shoe!
* Check for current test results - today's shoe models are commonly changed.
* Remember that these test results are often quite subjective.
It is very possible that your subjective opinion is far closer to the truth!
We continuously test, analyze and classify athletic shoes appearing on the market - issuing assortment recommendations to stores. Our tables of recommended shoes are chosen to compliment each other regarding various characteristics, etc. A buyer should not automatically conclude that one of these particular shoe models is best for him! However, chances are that you may very well find a suitable shoe-type among our lists and after video analysis and fitting. Our shoe selection does not eliminate other makes/models. For some people, these may well prove to be the best choice. Our personal comments and experiences are also included in these shoe assortment tables. As new models appear on the market, 2 to 3 times per year, we will renew and update the information.

 

Problems and discomforts: preventable and curable with a better choice of shoes.

Flat Feet
Flat feet are a common problem most often caused by a weakness in the foot's musculature. Often hereditary, it also may result from injury, fatigue or incorrect shoes. The strength of critical muscles may be insufficient, forcing other supporting parts of the foot to take over a function they cannot maintain for long. This affects both a flattening of the longitudinal arch and because some muscles are shared, a subsequent degradation of the forefoot's transverse arch. When both arches flatten, the inner side of the foot finally "collapses". In this condition, the foot and its' heel will tilt inwards along with an inward shift in the foot's center of gravity. On the inside of the foot this causes an inward "fall" in the anklebone and certain bones in the mid-foot, now visible by their abnormal protrusion. As more of the sole makes contact with the ground, the flattened footprint will widen in proportion.

Treatment
Where a one-sided flatfoot condition exists, particularly if it is recent (i.e. due to injury or paralysis), the causes should be immediately investigated and medical help should be advised. Flat feet conditions are often seen in both feet, to approximately the same degree, but with video analysis a tendency for pronation while running can vary substantially between the two feet. This type of foot requires (anti) pronation shoe with a straight inner (medial) last. If the foot can still not be corrected sufficiently, contact an orthopedic engineer for trials with orthotics.
A good advice to the flat footed is to not try to recreate or support the longitudinal arch with inserts.


Fallen transverse Arch (forefoot)
Often seen but with a fallen longitudinal arch, this condition can exist alone. One cause can be a cavus foot (abnormally high longitudinal arch - see below), resulting in a flattening of the transverse arch due to its' extreme load. Another cause can be a deviating big toe (hallux valgus).


Cavus Foot (hallux valgus)

Treatment for transverse arch defects
Measures include arch supports for the forefoot, specialized orthotics and shoes with wider toe-boxes. Corrective surgery may be indicated for a cavus foot or hallux valgus condition.

Cavus foot
 (extremely high longitudinal arch)
This extremely high arch causes a greater degree of rigidity than is normal in the foot. The area most affected by this extreme angularity is the mid-foot. Such a steep arch causes the bones in the forefoot to hold a sharp downward angle, resulting in all the weight in the forefoot bearing down on the ends of these long bones behind the toes. The heel shares the weight. Both callus development at the pressure points and pain are symptomatic.


Treatment
If the problem has existed to a limited extent since birth, the patient will require shoes with a curved last, and often orthotics with specialized forefoot and longitudinal arch supports. Certain areas on the orthotic and the shoe's inner sole may need to be freed or hollowed out, to eliminate all pressure on the foot's callused or sensitive pressure points. Some patients with cavus feet experience great discomfort. Since this condition often worsens with time, operation may well be necessary. In such cases a physician will examine for possible neuromuscular problems.

A common misconception states that a cavus foot supinates: most often it is quite the opposite (i.e. pronation).

 

Stiff Feet
Foot deformities of differing types may cause stiffness, which always translates into incorrect weight bearing. Softer, thicker shoe soles may be of help, but at times surgery is required. Physiotherapy and mobilisations may be of help.

Heel Complaints / Tender Heels
Tenderness and swelling around the Achilles tendon may be tendonitis (inflammation) or bursitis, both of which can be caused by the shoe's heel cap pressure, a heel which is too low, or incorrect positioning of the foot where the heel is forced to hold an outward angle. Tenderness below the outer ankle joint can be a tendon inflammation brought on by poor shoes. Pressure sensitivity on both sides of the ankle (both ankle bones) may indicate a cracked heel bone due to trauma or a jump. This crack may often not be detectable on x-ray before some weeks have passed. Patients with such symptoms should be referred to a physician. Flattened heels (atrophy) shows up as thin skin and tenderness in the heel cushion and is most often found in athletes and the aged. Cracked, split skin is common. When pressure is applied numerous characteristic "bubbles" can be seen to move outwards under the skin and the heel has lost its' natural cushioning ability. Treatment includes shoes with extra stable heel caps, shock absorbing heels, and in some cases specialized orthotics with heel cups which both contain and support the softer part of the patient's heel.

Heel Spur
Distinct needle-like pains under the foot at the leading edge of the heel bone where the tendons (plantar aponeurosis) running from the forefoot is attached to the heel, are symptomatic of this condition. The "spur" can often be seen on x-ray.

Treatment
For better weight distribution, a horseshoe-shaped inlay/orthotic with a hollow, to alleviate pressure sensitivity, can be one method. A program of stretching exercises for the muscles under the foot can be another. Local injections in the area of discomfort should be used with restrictions as well as should always be used as the last method and only after all other treatment methods have failed.

Inflammation of the plantar fascia
This is characterized by a diffuse tenderness in the entire longitudinal arch, but the pain can also be isolated to an area just in front of the heel bone. The fascia may in some cases feel swollen and hard and pain is felt during the propulsion phase when straining to carry the weight. Shoes with too soft a midsection may be to blame.

Treatment
Rest, orthotics with intensions to relieve pressure on the fascia and its points of attachment, as well as torsion-resistant shoes are some solutions. Physiotherapy may be required, as well as a physician's help with injections (used with restrictions) or medicine to control inflammation. This problem can prove long in healing.

Tendonitis in the Big Toe's flexor
Tenderness on the underside of the longitudinal arch a few centimeters ahead of the sensitive area normally associated with heel spur can be a symptom of this condition.

 

Treatment
Stretching exercises may help. Carefully examine the foot's behavior while walking and running to find the point of inflammation. The cause of this muscle pain most often can be found in poorly constructed orthotics or inlays which do not allow enough space for this tendon as it takes up the required strain for the propulsion phase. An incorrect type of shoe can also be suspect: for example, a shoe with a curved last with a flat foot condition.

Slipper Bumps
These are lumps on the top of the foot caused entirely by pressure or friction from poorly- fitting slippers and (wooden) clogs, etc.


Hammer Toes
This condition is characterized by toes held flexed and under constant strain, quite often symptomatic of a high arch or a deviating big toe. A transverse arch support or an orthotic may alleviate the problem. Shoes with wide, generous space for the toes are required.


Hallus valgus
Angled inwards toward the other toes, and often seen with a stiffened toe joint (hallux rigidus), this condition in the big toe is often found in the elderly. Both pain and a tendency to avoid putting weight on the big toe during the propulsion phase often leads to supination and incorrect weight bearing. Localized tenderness, diminished mobility, pain in the big toe's joint and, eventually, discomfort in the leg are symptomatic. This problem is most probably an inherited defect, but may also be aggravated by shoes with narrow toes.

Treatment
Forefoot arch supports, orthotics, wider shoes and perhaps physiotherapy, are standard treatments. Surgery is commonly necessary and gives good results. Do not recommend the same type of shoes after the operation!

Stiff Big Toe (hallux rigidus)
This condition is very common.
Treatment
Inlays, orthotics, as well as a roll-support placed under the forward edge of the transverse arch are standard treatments. Shoes with a ball-support or a curved outer sole to encourage a ”rolling-motion” in the step are also often helpful.

Periostitis
Periostitis is an inflammation of the membrane surrounding the bone. A common condition appearing as pain on the front of the lower leg (shin bone), periostitis can be brought on by excessive running on a hard surface wearing shoes with insufficient stability / shock absorption. It often occurs when a runner switches from running on a soft surface to a hard one, or, as a result of increased training. For both prevention and treatment, correct shoes suited to the surface on which they are to be used and to the runner's own style, are essential. There are often pronations problems in need of correction associated with this inflammation and at times even custom orthotics are indicated. Careful video analysis is critical in these cases, where very small foot deviations may have great importance.


"Area of pain associated with periostitis"

Insulation as well as applying heat locally can help against the pain. "Active rest" can also be practiced, where the athlete continues training without straining the muscles that are in pain. Chronic discomfort may require medical help.

 

Inflammation in muscles, tendons, and their points of attachment to the bone
These discomforts are often prescribed specific treatments after referral to a physician or physiotherapist. Avoid activities that cause pain. Locally insulating bandages or clothing may help. Muscle stretching exercises may be recommended for the muscles giving discomfort. The shoes need to be optimally suited to the runner and the track surface. Any change in the latter should be gradual. Remember that a change in running surface may demand a change in shoe model. Video analysis is also quite important.

Achilles Tendon Inflammation
Pain and tenderness at the point of attachment of the Achilles (heel) tendon is typical. Its' causes can vary from overwork or heavy weight bearing, to a change in track surface or walking / running uphill. Incorrect shoes are another cause (i.e. shoes with too low heels or with heel caps giving poor support, allowing the heel's tendon to bend instead of being held straight). Measures to prevent this condition can include avoiding the start-phase of an event and its' muscle strain thorough warm-ups, and stretching exercises before training.

Training shoes must be checked for correct heel height and good heel cap stability. Orthotics may be necessary. Sometimes as little as a 10 mm wedge under each heel is enough. Both shoes will need an equal adjustment to avoid unequal weight bearing and possible back problems. Patients with these symptoms should seek early medical attention. Eccentric muscle training may show good results.

Knee Discomforts
The knee's mechanics are directly dependant on the movements of the joints of the foot. For example, the deviation caused by pronation rotates the lower leg inwards, causing a relative shortening of the leg and an outward angling in the lower leg, all of which adversely affects the knee. The kneecap's position can even be affected, disrupting its' relationship to the thighbone. The problem is compounded as the anterior thigh muscle's connective tissue has an incorrect angle against the kneecap and the lower leg, negatively affecting the kneecap's other supportive structures, resulting in its' overexertion.

"Among other complications, the knee and lower leg are affected by deviant foot positions"

When one corrects pronation deviations it is critical to avoid overcorrecting. Begin instead with a partial correction, so that the shoe is somewhat straighter. The change in the foot's angle can otherwise become too great if you correct absolutely. Guard particularly against angling the foot so that an over-correction with supination tendencies occurs. This will surely cause discomfort. Concerning supination deviations, it is in our experience more important to be particularly thorough in seeing the foot assume a straight stance to eliminate pain/discomfort. The reason for this may be that the foot and lower leg have a degraded ability to absorb shock when supination is present. Straightening up the foot will lead to improved shock absorption and decreased levels of discomfort.

 

Runner's Knee
This painful condition occurs on the outside of the knee, appearing after a shorter period of running and as a rule, disappearing as soon as the runner stops. The pain typically begins again a few minutes later when running is once more initiated. The massive buttock-musculature's powerful tendon-band, which runs along the side of the thigh, ends up by following the outside of the knee to points of attachment both on the front, and on the outside of the lower leg, just below the knee joint. Runner's knee is caused by an irritation from the sweeping motion of this tendon on the outside of the knee joint.


Overstrain of the tensor fascia latae muscle is the cause of "Runner's knee"

Pro- and supination deviations in the foot can be the cause of the problem. Running only on one side of the road can also bring on the condition. Both gravel and asphalt road surfaces are normally canted toward each ditch for the sake of drainage. By running solely on one side of the road, the outside leg will always have further to travel to make contact, and will then touch down on an angled surface. The outside foot will perpetually be "seeking" the ground, which continuously overstrains the structures on the outside of this knee, resulting in pain. Once again, a correct choice in shoes, and possibly the use of orthotics, may prevent or reduce the discomfort. Stretching the muscle (m. tensor fasciae latae) will stretch the powerful tendon-band, and may reduce the problem. As a preventative measure, we recommend you plan your running so as to vary the road and track surface / do your running in the middle of the road.

Sprains and Ligament Injuries in the Foot.
Runners with a tendency for sprains must have shoes properly-fitted after a running test and video analysis. The shoe should be both stable and must hold the foot as straight as possible, preventing all tilting in any direction. If the shoe is still deficient, ankle supports or taping the ankles may be considered. Running should be done on a relatively flat surface, at least in the beginning. Coordination and strengthening exercises on a so-called "balance-board" is excellent for the ankles.

Blisters, abrasions, ingrown nails, calluses, and athlete's foot / fungus
All of these conditions can be caused or exacerbated by narrow, tight, or otherwise incorrect shoes. Choose your shoe model and shoe last with care, and be observant: any of the above conditions indicates the shoes are wrong for you. A seemingly small and inconsequential deviating foot angle can become magnified higher up in the leg. Discomfort can develop in the knee and hip, the small of the back, and even in the neck, from problems in the feet.

Back Problems

Incorrect weight bearing in the foot and the knee can be transmitted on up, into the small of the back and the neck. Since the entire skeleton is one, balanced, mechanical system, smaller deviations in the lower part of the body are compensated for by much larger deviations in its' movements further up, resulting in asymmetrical, strained muscle-activity and hence pain. Heels that are too high, for instance, cause an increased luntran lordosis/extension which in turn affects a backward lean to the neck, resulting in pain in these areas.
Copyright© 2002 Bernt Ersson