Sports Podiatry Info Blog has moved!

Hi all,

I’m sure it hasn’t escaped your attention that I have been rather quiet on here for far too long.  Huge apologies for this – my excuses include: increased clinical workloads, increased involvement in performing research (more info later), establishing my place on the London 2012 Olympic Games Podiatry Medical Team, and last but by no means least getting married.

In addition to all of the above I have a new – and hopefully improved – website, and my blog (which I fully intend to continue) has been made an integral part of this.  The ‘new’ blog can be found by going to my website and clicking on the ‘blog’ button at the top right of any page:

http://www.sportspodiatryinfo.co.uk/

As of this point all new posts will be made on the new blog; so please do drop by there if you can, and update your bookmarks accordingly.  Head over there now for a link to a newly published article on why I have such a problem with ‘Overpronation’.

Many thanks for all your continued interest and support.

Sports Podiatry Info is now on YouTube

Following a recent comment I received from an individual who said my blog posts were “good, but a bit wordy”, I have decided to venture out into making short video clips about various topics and uploading them to YouTube.  This will hopefully allow those who aren’t great fans of reading paragraph after paragraph of text to follow along too.  It is just an idea at present, but if it proves to have some legs then hopefully it will evolve into a good source of information to supplement this blog.

This first offering is a very short and introductory video discussing the way this information will be delivered, and some of the potential topics for future discussion.  I am of course very open to comments , and if I get enough requests for one subject then I will try to provide something if I can.

The videos will all be quite short (10-15 mins at most) and I aim to keep them quite simple, so they may be more appropriate for the undergraduate student or newly qualified Podiatrist.

More to come soon…

Choosing Running Shoes: The Evidence Behind the Recommendations

Following a media frenzy in 2010, the concept of running barefoot came under rather close scrutiny.  With respect to its potential long term risks/benefits the research is not yet available, so for many professionals the jury is still out and they remain healthily sceptical.  However these same professionals generally recommend road running shoes based on a model which has been used for decades.  At this point in time it seems only fair that this is re-visited and also put under the same scrutiny, with some of the available research relevant to running shoes looked at in closer detail.  This blog aims to do just this; to discuss how road running shoes are currently ‘prescribed’, and to see if there is any rationale for this current practice.

History

Road running shoes can be generally split into 3 groups – motion control shoes, stability shoes, and neutral/cushioned shoes.  Historically we have all been told that there are 3 main foot types (what a fantastic coincidence I hear you cry…) – the ‘flat’ or ‘pronated’ foot, the ‘normal’ or ‘neutral’ foot, and the ‘high arched’ or ‘supinated’ foot.

1. Flat/Pronated foot = Motion Control shoe 2. Normal/Neutral foot = Stability shoe 3. High/Supinated foot = Neutral/Cushioned shoe

It is not entirely clear where this model of shoe selection came from.  It’s conception may have been based upon the work of Colonel Harris and Major Beath, who performed an Army foot survey back in 1947, and whilst doing so invented an ingenious new method of assessing footprints.¹ It was in 1980 that ‘The Running Shoe book’ showed the first picture (as far as I’m aware) of the three arch types and how these may relate to running shoe selection.² Despite the lack of certainty regarding its origins, pretty much every edition of Runners World magazine printed since has regurgitated this information, as have most running shoe shop assistants, not to mention numerous websites (including those of many major shoe companies and sports injury professionals).  For several decades runners have therefore been advised to check their footprints (often easily assessed by observing the mark a wet foot leaves behind) and pick the corresponding shoe.  They are told this ensures ideal alignment and minimises injury risk.  Simples.  Or is it?

Before we continue take a look at the following foot (a freeze frame during running):

Have a think about what running shoe you would recommend for this individual based on the visual information you have.

To identify whether the well known model of shoe selection is appropriate we need to break it down and analyse the preconceptions it is based upon.  These are:

(A)   Pronation is consistently predictive of injury.

(B)   All individuals should be aligned identically (i.e. ‘normal’ or ‘neutral’).

(C)   The wet foot test (i.e. foot shape) is predictive of dynamic function.

(D)   Running shoe technology will actually achieve what it claims to.

If these points are not true, or not backed up by research, then the entire model falls apart.  So, let’s take a look at these preconceptions one at a time.

(A) Pronation is consistently predictive of injury.

Running stores and magazines seem to be fixated on pronation.  Most shoes are marketed with respect to how much ‘pronation control’ they offer.  Why is this?  Well, it has generally been thought that a more pronated foot type is a significant risk factor for injury.  However the fact is that there are very few prospective studies which have actually shown this, with numerous studies actually concluding that there is no association between foot type and injury.^3-9Two studies have even shown that a pronated foot is actually a protective factor against injury.^10,11

The point I’m trying to make is that the relationship between foot mechanics and lower limb injury is still not as well understood as we think (or as we would like).  But what we do know is that functioning in a pronated position does not mean that you will necessarily get injured.  In fact the experimental evidence suggests you are much more likely to get injured from training errors¹² or from dysfunctional hip musculature.¹³

Verdict = Pronation is not consistently predictive of injury

(B) All individuals should be aligned identically (i.e. ‘normal’ or ‘neutral’).

When referring to ‘ideal’ alignment what is actually meant?  What exactly is ‘normal’ when it comes to the alignment of the lower extremity?  Answer: We don’t know.  The word ‘normal’ is probably an inappropriate word to apply to the human body.  As far as normal foot alignment or mechanics is concerned, the normal (average) foot type reported in sampled populations is actually mildly to moderately pronated.^14-17 So why then is the main aim of the current running shoe selection model to align runners to ‘neutral’ (i.e. the foot sitting perpendicular to the horizontal ground)?

When we consider that the subtalar joint (the joint where pronation and supination occurs) has variable anatomy ^18,19it seems obvious that function will not be the same for everyone, and therefore that the ‘optimum’ position to be in would differ from person to person.  Unsurprisingly, differences in foot alignment between individuals is reported to be high.²⁰

It still amazes me that in a world where human variation is so vast in almost every aspect of our being, that when it comes to running there is a suggestion that we should all be in one particular alignment or position.  The reality is that each of us most likely has own preferred alignment – a subject specific ‘normal’.

Verdict = Individuals should not all be aligned similarly. ‘Normal’ alignment is subject specific.

(C) The wet foot test (i.e. foot shape) is predictive of dynamic function.

The association between static foot measures and dynamic function has been well researched in the literature.  Several different methods of assessing foot shape, arch height and foot posture in static standing have been investigated, with the conclusions generally being that there is no association between these measures and dynamic function (what the foot does when we actually run).^21-25

The work which really puts the wet foot test out of business was completed by a team of researchers from the US army over the last year or so.  Their prospective studies assigned running shoes based on plantar foot shape prior to basic military training, and investigated if this influenced injury risk at all.  They showed that assigning running shoes based on the footprint shape had little influence on injury risk in Air Force Basic Training,²⁶ Marine Corps Basic Training,²⁷and Army Basic Combat Training.²⁸

Verdict = Foot shape is NOT predictive of dynamic function.  The wet foot test is nonsense.

(D) Running shoe technology will actually achieve what it claims to.

The technology that shoes provide can be generalised into 2 main areas.  They offer cushioning, and market this as essential for the dampening of the high impacts associated with running, and they offer increased durometer (stiffer/harder) midsoles which are aimed at controlling or reducing pronation.  These technologies have been called into question before, with some researchers suggesting that the protected environment a modern running shoe provides will diminish sensory feedback, resulting in inadequate impact moderating behaviour and actually serve to increase injury risk.^29,30

A 2010 study concluded that the prescription of shoes with elevated cushioned heels and pronation control systems tailored to an individuals foot type was not evidence based³¹ and another very recent piece of research suggested this approach was overly simplistic and potentially injurious.³² How did the latter study come to this conclusion? Well to very briefly summarise: every single runner in their study who had been classified as having a ‘highly pronated’ foot type and was subsequently put into a motion control shoe reported an injury during a 13 week half marathon training programme.  Let me repeat that – highly pronated feet that were put into motion control shoes resulted in injury.  Yet that is exactly what the current shoe selection model suggests.  So, let’s go back to the video gait analysis snapshot:

Given what you have read so far, what shoe would you recommend this person now? Has it changed from earlier?

Back to the running shoe research:  Numerous studies agree that shoes with softer midsoles (cushioned/neutral shoes) result in greater pronation values, and shorter times to reach maximum pronation i.e. they make individuals pronate more, and pronate quicker.^33-36 Does this sound bad to you? [If so go back and read the research which refutes preconception (A)].  Most of these studies also concluded that harder/stiffer midsoles (such as those found in stability and motion control shoes) significantly decrease the speed and magnitude of pronation.  Some of these shoes now also have a slight varus tilt (they are higher on the inside of the heel than they are on the outside).  Research has also shown that this decreases foot level pronation.^37,38 (Remember these studies are just investigating kinematics/alignment and not injury).

So ‘anti-pronatory’ shoes with stiffer midsoles are actually doing what they promise to.  The problem is we don’t know whether we need them to do it for us or not.  And as an aside, varus posting/tilting was shown in one study to increase tibial shock and vertical loading rates.³⁹ (Is this perhaps why all those injuries occurred in the motion control shoes in the aforementioned study?)

Finally, let’s not forget cushioning.  That must reduce the amount of force we are subjected to when running – right?  Wrong.  As shoe cushioning decreases runners modify their patterns to maintain constant external loads.⁴⁰ However, it is thought to contribute to comfort, and this seems to be the most important variable on which to select sports shoes, which we will talk about shortly.

Verdict = There is very little research investigating the relationship between running shoes and injury prevention.  Stiffer midsoles do reduce pronation speed and magnitude, but in doing so may increase vertical loading rates.  Running shoe ‘cushioning’ may be a myth.

Summary

It seems that the current model upon which running shoes are recommended/chosen is erroneous.  Its foundations are based upon preconceptions which have been shown to be false.  Due to significant within-species variation it is ridiculous to try and align people identically, (and to aim to do so in a pre-selected ‘normal’ position which is highly unlikely to be ‘normal’ for most individuals is potentially injurious).  Shoes do seem to generally achieve what they claim to.  However, our understanding of whether they actually need to achieve these variables (and who would benefit from each variable) is poor at present.

And so, the current method of being recommended a shoe still continues (and I imagine it will for some time).  Why?

1. Very few people realise it is erroneous.
2. At the moment we do not have anything to replace it with.
3. It is fantastically simple.
4. People don’t generally like change.

The future

Moving forward, a much better model would be to focus on identifying an optimum midsole stiffness (which may be variable) for an individual, combined with their optimum alignment/movement patterns for a given activity (i.e. the position in which their injury risk is minimised and their performance is maximised, irrespective of its visual alignment). However, much more research is required before we fully understand how to clinically achieve this.

The concept of intelligent shoes which modify their midsole characteristics depending on the step by step requirements and effectively ‘tune’ themselves to the wearer and the surface they are on may sound like something from Back to the Future, but it is probably only a matter of time before we start seeing this sort of advancement in our running shoe technology.  However, it doesn’t change the fact that we need a greater understanding of injury risk factors, and that these are still likely to be subject (and activity) specific.

Conclusions

So where does this leave the runner choosing a pair of shoes in 2011? There are many choices. Neutral? Stability? Motion Control? Vibram Five Fingers? Barefoot? Hopefully by now you realise that there is no simple answer.

All decisions could and should be based on one main factor in my opinion: comfort. Believe it or not comfort has been linked to injury frequency reduction⁴¹ and is thought to be the most important variable for sports shoes, and a focal point for any future sports shoe development.⁴² We all know that comfort is subjective and subject specific⁴³ so with that in mind only the wearer can confidently choose the most appropriate shoe for themselves.  [Be wary of the shop assistant/Podiatrist who tells you the exact make and model shoe which is best for you]. What one person finds comfortable will differ greatly from another; perhaps this is why some people find that stiff supportive shoes work best for them, and others discovered that barefoot running was the answer to their long history of injury woes.

As most runners know, it can often be a little bit of trial and error with regard to finding the ‘right’ shoe.  Once you’ve found what works for you (or if you have found it already) then don’t change it.

Irrespective of the advice given in the shoe shop/magazines about your ‘pronation’; on current evidence you may be just as well off picking a shoe based on comfort alone, and subscribing to a course of Pilates and adopting sensible training habits.

P.S. How are you getting on with your decision on what shoes to recommend for this chap?

References

1. Harris RI, & Beath T: (1947). Referenced from a secondary source: The Journal of Bone & Joint Surgery (1950), Vol 32B, No 1, p143-144.
2. Cavanagh PR: The Running Shoe Book, Anderson World, Inc., Mountain View, California, 1980.
3. Barrett JR, Tanji JL, Drake C, et al: High versus low-top shoes for the prevention of ankle sprains in basketball players. A prospective randomized study. The American Journal of Sports Medicine 21: 582, 1993.
4. Twellaar M, Verstappen FT, Huson A, et al: Physical characteristics as risk factors for sports injuries: a four year prospective study. International Journal of Sports Medicine 18: 66, 1997.
5. Wen DY, Puffer JC, Schmalzried TP, et al: Injuries in runners: a prospective study of alignment. Clinical Journal of Sport Medicine 8: 187, 1998.
6. Beynnon BD, Renstrom PA, Alosa DM, et al: Ankle ligament injury risk factors: a prospective study of college athletes. Journal of Orthopaedic Research 19: 213, 2001.
7. Hetsroni I, Finestone A, Milgrom C, et al: A prospective biomechanical study of the association between foot pronation and the incidence of anterior knee pain among military recruits. Journal of Bone and Joint Surgery Br88: 905, 2006.
8. Reinking MF, Austin TM, Hayes AM: Risk factors for self-reported exercise-related leg pain in high school cross-country athletes. Journal of Athletic Training 45: 51, 2010.
9. Franettovich M, Chapman AR, Blanch P, et al: Altered neuromuscular control in individuals with exercise-related leg pain. Medicine and Science in Sport and Exercise 42: 546, 2010.
10. Giladi M, Milgrom C, Stein M, et al: The low arch, a protective factor in stress fractures. Orthopaedic Review 14: 81, 1985.
11. Cowan D, Jones B, Robinson J: Foot morphologic characteristics and risk of exercise related injury. Archives of Family Medicine 2: 773, 1993
12. James SL, Bates BT, Osternig LR: Injuries to runners. American Journal of Sports Medicine 6: 40, 1978.
13. Ferber R, Hreljac A, Kendall KD: Suspected mechanisms in the cause of overuse running injuries: a clinical review. Sports Health: A Multidisciplinary Approach 1: 242, 2009.
14. Sobel E, Levitz SJ, Caselli MA, et al: Re-evaluation of the relaxed calcaneal stance position. Journal of the American Podiatric Medical Association 89: 258, 1999.
15. Scharfbillig R, Evans A, Copper A, et al: Criterion validation of four criteria of the foot posture index. Journal of the American Podiatric Medical Association 94: 31, 2004.
16. Redmond A, Crosbie J, Ouvrier R: Development and validation of a novel rating system for scoring standing foot posture: the foot posture index. Clinical Biomechanics 21: 89, 2006.
17. Redmond AC, Crane YZ, Menz HB: Normative values for the foot posture index. Journal of Foot and Ankle Research 1: 6, 2008.
18. Bruckner J: Variations in the human subtalar joint. Journal of Orthopaedic and Sports Physical Therapy 8: 481, 1987.
19. Forriol Campos F, Gomez Pellico L: Talar articular facets. Acta Anatomica 134: 124, 1989.
20. Nester CJ: Lessons from dynamic cadaver and invasive bone pin studies: do we know how the foot really moves during gait? Journal of Foot and Ankle Research 2: 18, 2009.
21. Razeghi M, Batt ME: Foot type classification: a critical review of current methods. Gait and Posture 15: 282, 2002.
22. Hamill J, Bates BT, Knutzen KM, et al: Relationship between selected static and dynamic lower extremity measures. Clinical Biomechanics 4: 217, 1989.
23. McPoil TG, Cornwall MW: The relationship between static lower extremity measures and rearfoot motion in gait. The Journal of Orthopaedic and Sports Physical Therapy 24: 309, 1996.
24. Cashmere T, Smith R, Hunt A: Medial longitudinal arch of the foot: Stationary versus walking measures. Foot and Ankle International 20: 112, 1999.
25. Trimble MH, Bishop MD, Buckley BD, et al: The relationship between clinical measurements of lower extremity posture and tibial translation. Clinical Biomechanics 17: 286, 2002.
26. Knapik JJ, Brosch LC, Venuto M, et al: Effect on injuries of assigning shoes based on foot shape in air force basic training. American Journal of Preventative Medicine 38: S197, 2010.
27. Knapik JJ, Trone DW, Swedler DI, et al: Injury reduction effectiveness of assigning running shoes based on plantar shape in marine corps basic training. American Journal of Sports Medicine 38: 1759, 2010.
28. Knapik JJ, Swedler DI, Grier TL, et al: Injury reduction effectiveness of selecting running shoes based on plantar shape. Journal of Strength and Conditioning Research 23: 685, 2009.
29. Robbins SE, Hanna AM: Running-related injury prevention through barefoot adaptations. Medicine and Science in Sports and Exercise 19: 148, 1987.
30. Robbins SE, Gouw GJ: Athletic footwear: Unsafe due to perceptual illusions. Medicine and Science in Sports and Exercise 23: 217, 1991.
31. Richards CE, Magin PJ, Callister R: Is your prescription of distance running shoes evidence-based? British Journal of Sports Medicine 43: 159, 2010.
32. Ryan MB, Valiant GA, McDonald K, et al: The effect of three different levels of footwear stability on pain outcomes in women runners: a randomised control trial. British Journal of Sports Medicine (2010). doi: 10.1136/bjsm.2009.069849.
33. Clarke TE, Frederick EC, Hamill CL: The effects of shoe design parameters on rearfoot control in running. Medicine and Science in Sports and Exercise 15: 376, 1983.
34. Hamill J, Bates BT, Cole KG: Timing of lower extremity joint actions during treadmill running. Medicine and Science in Sports and Exercise 24: 807, 1992.
35. Wit BD, Lenoir M: The effect of varying midsole hardness on impact forces and foot motion during foot contact in running. Journal of Applied Biomechanics 11: 395, 1995.
36. Kersting UG, Bruggermann GP: Midsole material-related force control during heel-toe running. Research in Sports Medicine 14: 1, 2006.
37. Van Woensel W, Cavanagh PR: A perturbation study of lower extremity motion during running. International Journal of Sports Medicine 34: 1844, 1992.
38. O’Connor K, Hamill J: The role of selected extrinsic foot muscles during running. Clinical Biomechanics 19: 71, 2004.
39. Perry SD, Lafortune MA: Influences of inversion/eversion of the foot upon impact loading during locomotion. Clinical Biomechanics 10: 253, 1995.
40. Kong PW, Candelaria NG, Smith DR: Running in new and worn shoes: a comparison of three types of cushioning footwear. British Journal of Sports Medicine 43: 745, 2009.
41. Mundermann A, Stefanyshyn DJ, Nigg BM: Relationship between footwear comfort of shoe inserts and anthropometric and sensory factors. Medicine and Science in Sports and Exercise 33: 1939, 2001.
42. Nigg BM: Biomechanics of Sports Shoes, Topline Printing Inc, Calagary, Alberta, Canada, 2010.
43. Miller JE, Nigg BM, Liu W, et al: Influence of foot, leg and shoe characteristics n subjective comfort. Foot and Ankle international 21: 759, 2000.

Plantar Calcaneal (Heel) Spurs

Heel pain is an incredibly common condition and there are very few Podiatrists who won’t see it on a daily basis in their clinics.  There are numerous different causes of heel pain, (not all mechanical), but the area that this blog entry is going to focus on in particular is the plantar calcaneal/heel spur.  It is yet another source of controversy, with no definitive agreement on the relationship of the spur and the surrounding tissues, or the actual source of the symptoms (if any) seen clinically.

Historically, it has been commonly accepted that heel spur formation is an abnormal finding and very closely correlated with the symptoms of heel pain.  It was reported that excessive traction (pulling) of the plantar fascia on its attachment at the heel resulted in chronic inflammation, which in turn resulted in a reactive ossification and subsequent extra bone forming in the shape of a ‘spur’. ^1-3 This is perhaps why heel spurs and ‘plantar fasciitis’ are still to this day thought by many to be one entity.  Causation has been a point of confusion; does the traction and inflammation cause a heel spur, or does a heel spur cause tissue inflammation?  A chicken and egg scenario.  It is not uncommon to see statements that ‘plantar fasciitis’ is caused by heel spurs (admittedly this is on websites rather than academic journals), but is this factually correct?

The plantar calcaneal spur has been classically described as a bone outgrowth localised just anterior to the medial tuberosity of the calcaneus.⁴ This can not often be palpated clinically, but only seen radiologically as shown in the x-ray on the right above.

Another long term belief has been that individuals with heel pain are more likely to have pronated (flat) feet.^5,6 As research has shown that lowering of the medial longitudinal arch of the foot increases plantar fascial tension⁷ it is easy to see how the connection between foot pronation, heel pain and heel spurs has been made.  However the concern is that any individual who presents to a specialist with heel pain and ‘flat feet’ could be hastily assigned a diagnosis of “plantar fasciitis caused by a heel spur”.  This is clearly unacceptable, and a specialist should have a much more thorough understanding of the research behind the pathological process.  So, how common are heel spurs?  Are they always problematic? Are they actually caused by traction? And what is their relationship with the plantar fascia?

How common are heel spurs?

Studies have shown that heel spurs are more common in pain free individuals than first thought, and it has been reported that anywhere between 11 and 27% of the population have radiographic evidence of a spur.^5,8-13 Clearly this suggests they are not always associated with symptoms, and are not necessarily considered as ‘abnormal’ as once thought.  Interestingly, even a study performed over 45 years ago on 323 patients concluded that the plantar calcaneal spur was never the cause of pain and probably a normal manifestation of the aging process.¹⁴

However, the research does suggest that calcaneal spurs do seem to be over-represented in certain groups, such as females,^10,11,13 individuals with osteoarthritis^15,16 and older people.^11,13,15,16 Calcaneal spurs have also found to be more common in those who are overweight.¹⁷

Where are heel spurs?

MRI of heel spur (arrow). PF=plantar fascia. M=1st layer of foot muscles

As I have already mentioned, it has long been thought that heel spurs and plantar fascia problems were undeniably linked.  Google ‘heel spurs’ and the term ‘plantar fasciitis’ is never far behind.  However, it is interesting to hear how the anatomic studies report the actual location of the bony protrusion.  Far from agreeing it resides solely within the plantar fascia as once thought, many studies found it can also be found above the plantar fascia.^4,12,18 Some found it was much more commonly located in the other intrinsic musculature, (namely Flexor Digitorum Brevis and Abductor Digiti Minimi)^4,18,19 and one study was as bold to firmly conclude that spurs do not develop within the plantar fascia.²⁰

What is clear is that there is huge variability in the location of heel spur formation, and if we cannot unequivocally state that the spur is within the fascia (which we cannot) then the validity of its link with ‘plantar fasciitis’ is questionable.

What causes heel spurs?

As previously mentioned, the traditional theory for formation of plantar calcaneal spurs is what Menz and colleagues¹⁶ refer to as the longitudinal traction hypothesis, i.e. the plantar fascia pulling on the heel bone and causing the formation of a spur.  Despite the anatomical studies showed that the spur is far from consistently found in the fascia, it has been suggested that there could be an element of tensile force exerted on the calcaneus from a variety of the other structures which attach to it.^4,19

An alternative theory, termed the vertical compression hypothesis¹⁶ and was proposed by Kumai and Benjamin in 2002.²⁰ This theory suggests that calcaneal spurs are outgrowths which form in response to repetitive vertical stress in an attempt to protect against microfractures.  This idea is supported by histological studies which show that the bony trabeculae are NOT aligned in the direction of soft tissue traction.^16,18 Li and Muehleman¹⁸ found that the direction of the trabeculae suggested that the force causing the pathological response was consistent with the external ground reaction force vector.

Conclusions

So what does all this mean in plain English?  It means that we used to think a spur was caused by the plantar fascia pulling on the bone.  This is highly unlikely as the spur is seldom found in the plantar fascia.  If traction is the cause it is more likely to be caused by other musculature such as Flexor Digitorum Brevis or Abductor Digiti Minimi.  However these bony protrusions could instead be caused by the repetitive vertical loading (the heel continuously hitting the floor, and the floor of course hitting it back) with the spur forming as a protective mechanism.  Of course we cannot overlook the fact that there may be a combination of both traction and compression present in the aetiology of spur development.  We also know that anywhere up to a quarter of the population may have a heel spur, but this will not always be problematic.

So, in summary:

The pathophysiology of plantar calcaneal heel spurs is poorly understood.

The presence of a plantar calcaneal spur does not always lead to the development of heel pain.

Plantar calcaneal spurs do appear to be associated with obesity, osteoarthritis and the aging process.

It is unclear whether spur formation is due to longitudinal traction of the plantar tissues or an adaptive response to vertical loading/compression (or both).

It is erroneous to assume there is a causal relationship between plantar calcaneal spurs and ‘plantar fasciitis’.

References

1. DuVries, H.L. (1957). Heel spur (calcaneal spur). Archives of Surgery, 74: 536-542.
2. Furey, J.G. (1975). Plantar fasciitis: the painful heel syndrome. Journal of Bone and Joint Surgery Am, 57: 672-673.
3. Bergmann, J.N. (1990). History and mechanical control of heel spur pain. Clinics in Podiatric Medicine and Surgery, 7: 243-259.
4. Abreu, M.R., Chung, C.B., Mendes, L. et al. (2003). Plantar calcaneal enthesophytes: new observations regarding sites of origin based on radiographic, MR imaging, anatomic, and paleopathologic analysis. Skeletal Radiology, 32: 13-21.
5. Prichasuk, S., Subhadrabandhu, T. (1994). The relationship of pes planus and calcaneal spur to plantar heel pain. Clinical Orthopaedics and Related Research, 306: 192-196.
6. Irving, D.B., Cook, J.L., Young, M.A. et el. (2007). Obesity and pronated foot type may increase the risk of chronic plantar heel pain: a matched case-control study. BMC Musculoskeletal Disorders, 8: 41.
7. Kogler, G.F., Solomonidis, S.E., Paul, J.P. (1996). Biomechanics of longitudinal arch support mechanisms in foot orthoses and their effect on plantar aponeurosis strain. Clinical Biomechanics, 11: 243-252.
8. Rubin, G., Witten, M. (1963). Plantar calcaneal spurs. American Journal of Orthopaedics, 5: 38-41.
9. McCarthy, D.J., Gorecki, G.E. (1979). Anatomical basis of inferior calcaneal lesions: a cryomicrotomy study. Journal of the American Podiatric Medical Association, 69: 527-536.
10. Shama, S.S., Kominsky, S.J., Lemont, H. (1983). Prevalence of non-painful heel spur and its relation to postural foot position. Journal of the American Podiatric Medical Association, 73: 122-123.
11. Banadda, B.M., Gona, O., Vas, R., et al. (1992). Calcaneal spurs in a black African population. Foot & Ankle, 13: 352-354.
12. Barrett, S.L., Day, S.V., Pignetti, T.T. et al. (1995). Endoscopic heel anatomy: analysis of 200 fresh frozen specimens. Journal of Foot & Ankle Surgery, 34: 51-56.
13. Riepert, T., Drechsler, T., Schild, H. et al. (1996). Estimation of sex on the basis of radiographs of the calcaneus. Forensic Science International, 77: 133-140.
14. Lapidus, P.W., Guidotti, F.P. (1965). Painful heel: report of 323 patients with 364 painful heels. Clinical Orthopaedics and related Research, 39: 178-186.
15. Gerster, J.C., Vischer, T.L., Bennani, A. et al. (1977). The painful heel. Comparative study in rheumatoid arthritis, ankylosing spondylitis, Reiter’s syndrome, and generalised osteoarthritis. Annals of the Rheumatic Diseases, 36: 343-348.
16. Menz, H.B., Zammit, G.V., Landorf, K.B. et al. (2008). Plantar calcaneal spurs in older people: longitudinal traction or vertical compression? Journal of Foot & Ankle Research, 1:7.
17. Sadat-Ali, M. (1998). Plantar fasciitis/calcaneal spur among security forces personnel. Military Medicine, 163: 56-57.
18. Li, J., Muehleman, C. (2007). Anatomic Relationship of Heel Spur to Surrounding Soft Tissues: Greater variability than previously reported. Clinical Anatomy, 20: 950-955.
19. Smith, S., Tinley, P., Gilheany, M. et al. (2007). The inferior calcaneal spur – Anatomical and histological considerations. The Foot, 17: 25-31.
20. Kumai, T., Benjamin, M. (2002). Heel spur formation and the subcalcaneal enthesis of the plantar fascia. The Journal of Rheumatology, 29: 1957-1964.

The Transverse Metatarsal Arch

It is often stated that the human foot has 3 arches; two longitudinal arches and the transverse arch (sometimes also referred to as the metatarsal arch).¹ Whereas the presence of longitudinal arches are unanimously accepted, the transverse metatarsal arch of the foot is considered to be quite controversial.  Believe it or not its existence has been debated since last century.  But what is the transverse metatarsal arch?  And what does the research actually tell us about it?

The existence of a transverse arch at the metatarsal region would require the pressure to be greatest at the areas beneath the 1^st and 5^th metatarsal heads, and the area of the 2^nd, 3^rd and 4^th metatarsal heads to be elevated relative to this.  This gives us the ‘tripod’ like weight distribution of the foot which was first described by Kapandji in 1970.² However, the first descriptions of the transverse metatarsal arch date back as far as 100 years prior to Kapandji’s work³ and several papers published in Germany between 1882 and 1927 actually concluded that no transverse arch of the foot was usually present.^4-7 Much of the research produced following Kapandji’s work concurs with these conclusions regarding the transverse metatarsal arch being a misnomer.

So if the presence of a transverse metatarsal arch has long been questioned, why have so many authors, and indeed medical professionals, subscribed to this theory for so long (and continue to do so) in spite of growing evidence against it?

The conception of the foot bearing its weight on three points must be quite attractive in order to persist (Jones, 1941)⁸

When a patient presents with diffuse pain across the forefoot, what should be performed is thorough examination of the region, identification of the anatomical structure which is involved, and then a management plan directed towards reducing the symptoms with the most appropriate treatment available.  However, all too often a clinician will diagnose ‘metatarsalgia’ (NOT a diagnosis, but we’ll save that for another blog) caused by ‘dropped metatarsals’ or ‘a fallen metatarsal arch’.  It’s very quick and very easy, and you can see how it doesn’t require too much thinking.  For these clinicians to accept that a transverse metatarsal arch does not exist would require them to change their entire clinical practice, and for many this sort of paradigm shift in thinking is too uncomfortable to accept, so instead they continue as they are.

So, 100 year old journal articles written in German aside, lets look at some of the more current research which has looked at the mythical transverse metatarsal arch.

In 1997, Daentzer et al.⁹ performed a study on 100 feet.  The age range of the participants in the study was between 10-72 years old.  None of the participants had any foot deformity or symptoms.  Ultrasonography was performed at the level of the metatarsal heads in both non weight bearing and weightbearing.  Barefoot plantar pressure measurements were recorded using a force plate.  Their findings/conclusions: Pressures are usually highest underneath the 2^nd, 3^rd and 4^th metatarsal heads, there is no transverse metatarsal arch, and the forefoot is normally flat at the level of the metatarsal heads.

In 1999, Luger et al.¹⁰ performed a study on 720 feet (the largest study to my knowledge).  The age range of the participants in the study was 18-83 years old.  Interestingly they included individuals with a variety of foot symptoms and abnormalities as well as pain free individuals.  The all had static and dynamic barefoot pressure measurements taken.  Their findings/conclusions: Only 22 feet out of 720 (3%) had a dynamic metatarsal arch whilst walking, and this was only found in the feet classified as having deformity or pain.  Not only was a transverse metatarsal arch rarely seen, but they concluded that it actually indicated a possible pathological deformity (i.e it is an abnormality which may cause problems)

In 2003, Kanatli et al.¹¹ performed a study on 32 feet.  The age range of the participants in the study was 20-30 years old.  All participants were pain free and had no foot deformities.  Barefoot plantar pressure measurements were taken whilst walking.  Their findings/conclusions: Significantly higher pressures were recorded beneath the 2nd and 3^rd metatarsal heads, and the transverse metatarsal arch did not exist in normal subjects.

As you can see one of the common findings seen in the research discussed has been that higher pressures are not seen beneath the 1^st and 5^th metatarsal heads during gait.  Other authors have investigated this employing pressure measurement equipment and found that the pressures in the middle metatarsals are consistently greater than the 1^st and 5^th metatarsals.^12,13 All of the research suggests that the tripod configuration of the foot is completely erroneous, and without this, it is obvious that it is not possible for there to be a transverse metatarsal arch.  Clinicians who continue to talk about the transverse arch, and offer treatments for its ‘collapse’ are either uninformed, bogged down in old habits or in denial.

References

1. Williams, P.L. et al. (1995) Gray’s Anatomy. 38^th Edition, Churchill Livingstone, New York.
2. Kapandji, L.A. (1970) The Physiology of the Joints. E & S Livingstone, Edinburgh.
3. Henle, J. (1871) Handbuch der Knochenlehre des Menschen. Vieweg, Braunschweig.
4. Beely, F. (1882) Zur Mechanik des Stehens. Uber die Bedeutung des Fussgewolbes im Stehen. Arch klin Chir, 27: 457-471.
5. Momburg, F.A. (1909) Die Stutzpunkte des Fusses beim Gehen und Stehen. Dtsch med Wschr, 4: 148-152.
6. Frostell, G. (1925) Beitrag zur Kenntnis der vorderen Stutzpunkte des Fusses, sowie des Fusswinkels beim Stehen und Gehen. Z  Orthop Chir, 47: 3-54.
7. Abramson, E. (1927) Zur Kenntnis der Mechanik des Mittelfusses. Skand Arch Physiol, 51: 175-234.
8. Jones, R.L. (1941) The Human Foot. An experimental study of its mechanics, and the role of its muscles and ligaments in support of the arch. American Journal of Anatomy, 68: 1-39.
9. Daentzer, D., Wulker, N., & Zimmermann, U. (1997) Observations concerning the transverse metatarsal arch. Foot and Ankle Surgery, 3: 15-20.
10. Luger, E.J., Nissan, M., Karpf, A., Steinberg, E.L., & Dekel, S. (1999) Patterns of weight distribution under the metatarsal heads. The Journal of Bone & Joint Surgery (Br), 81: 199-202.
11. Kanatli, U., Yetkin, H., & Bolukbasi, S. (2003) Evaluation of the transverse metatarsal arch of the foot with gait analysis. Arch Orthop Trauma Surg, 123: 148-150.
12. Cavanagh, P.R., Rodgers, M.M., & Iiboshi, A. (1987) Pressure distribution under symptom-free feet during barefoot standing. Foot and Ankle, 7: 262-276.
13. Hennig, E.M., & Milani, T.L. (1993) Die Dreipunktuntersttzung des Fusses. Eine Druckverteilungsanalyse bei statischer und dynamischer Belastung. Z Orthop, 131: 279-284.