High Heels and …..Orthotics?

What better way to end the year than to talk about something that some of you have worn last evening. Not only clean underwear, but also high heels!

You have heard all about high heels here on the blog (if not, click here). Now here is some info that may be surprising! This study found that increased heel height caused increased plantar pressures (no surprises) BUT the use of an orthotic or arch pad, attenuated impact forces. IOHO not a reason to wear heels (though we DO like the way they look : )) but if you need to wear them (really? you need to wear them?), then maybe consider an insert to make it more bearable.

Ivo and Shawn                                              

                           

Appl Ergon. 2005 May;36(3):355-62.

Effects of shoe inserts and heel height on foot pressure, impact force, and perceived comfort during walking.

Source

Department of Industrial Management, National Taiwan University of Science and Technology, No. 43, Kee-Lung Road, Sec IV, Taipei, Taiwan, 106 ROC. yhlee@im.ntust.edu.tw

Abstract

Studying the impact of high-heeled shoes on kinetic changes and perceived discomfort provides a basis to advance the design and minimize the adverse effects on the human musculoskeletal system. Previous studies demonstrated the effects of inserts on kinetics and perceived comfort in flat or running shoes. No study attempted to investigate the effectiveness of inserts in high heel shoes. The purpose of this study was to determine whether increasing heel height and the use of shoe inserts change foot pressure distribution, impact force, and perceived comfort during walking. Ten healthy females volunteered for the study. The heel heights were 1.0cm (flat), 5.1cm (low), and 7.6cm (high). The heel height effects were examined across five shoe-insert conditions of shoe only; heel cup, arch support, metatarsal pad, and total contact insert (TCI). The results indicated that increasing heel height increases impact force (p<0.01), medial forefoot pressure (p<0.01), and perceived discomfort (p<0.01) during walking. A heel cup insert for high-heeled shoes effectively reduced the heel pressure and impact force (p<0.01), an arch support insert reduced the medial forefoot pressure, and both improved footwear comfort (p<0.01). In particular, a TCI reduced heel pressure by 25% and medial forefoot pressure by 24%, attenuate the impact force by 33.2%, and offered higher perceived comfort when compared to the non-insert condition.

Too much pressure for the holidays? Take a look at that midsole of yours…

In the vein of last weeks post on plantar pressures, we find that midsoles DO DECREASE plantar pressures, especially across the midfoot (30% less pressure in this study), again dependent on foot type (In this study, low vs high arched individuals). They also INCREASE plantar contact area. Contact area can be useful for helping to influence biomechanics of different foot types (often more contact area = more force attenuation)

We also saw that they increase pressures LATERALLY (see our post here).

Bottom line? You need to look at foot type and remember that “shoes are medicine”. Watch what you are prescribing and think about what you are trying to accomplish. There is no substitute for good biomechanics.

We are The Gait Guys. Bringing you the best of gait, each week.

Shoe Types and plantar pressures

J Am Podiatr Med Assoc. 2009 Jul-Aug;99(4):330-8. Effect of running shoe type on the distribution and magnitude of plantar pressures in individuals with low- or high-arched feet. Molloy JM, Christie DS, Teyhen DS, Yeykal NS, Tragord BS, Neal MS, Nelson ES, McPoil T. Source US Army-Baylor University Doctoral Program in Physical Therapy, Ft Sam Houston, TX 78234-6138, USA. Joseph.Molloy@amedd.army.mil

Abstract BACKGROUND:

Research addressing the effect of running shoe type on the low- or high-arched foot during gait is limited. We sought 1) to analyze mean plantar pressure and mean contact area differences between low- and high-arched feet across three test conditions, 2) to determine which regions of the foot (rearfoot, midfoot, and forefoot) contributed to potential differences in mean plantar pressure and mean contact area, and 3) to determine the association between the static arch height index and the dynamic modified arch index.

METHODS:

Plantar pressure distributions for 75 participants (40 low arched and 35 high arched) were analyzed across three conditions (nonshod, motion control running shoes, and cushioning running shoes) during treadmill walking.

RESULTS:

In the motion control and cushioning shoe conditions, mean plantar contact area increased in the midfoot (28% for low arched and 68% for high arched), whereas mean plantar pressure decreased by approximately 30% relative to the nonshod condition. There was moderate to good negative correlation between the arch height index and the modified arch index.

CONCLUSIONS:

Cushioning and motion control running shoes tend to increase midfoot mean plantar contact area while decreasing mean plantar pressure across the low- or high-arched foot.

all material copyright 2012  The Gait Guys/ The Homunculus Group. Please ask before using our stuff or Santa will bring you athletes foot this holiday season. 

Defective Running Shoes as a contributing Factor in Plantar Fascitis in a Triathlete

Wilk B, Fisher K, Guitierrez W: JOSPT 2000;30(1):21-31

http://www.jospt.org/issues/articleID.407/article_detail.asp

Overview: Case study of 40 yo male triathlete who developed R sided plantar fascitis after completing a half ironman (2K swim, 90K bike, 21K run). The study describes the factors contributing to the injury, the rehab process, and shoe construction along with the symptoms of plantar fascitis.

Authors Conclusion: A running shoe manufacturing defect was found that possibly contributed to the development of plantar fascitis. Assessing athletic shoe construction may prevent lower extremity overuse syndromes.

What The Gait Guys Say: Plantar fascitis is something we see clinically many times in our practices. It is often due to overpronation of the midtarsal joint (talo-navicular and calcaneo-cuboid) in midstance, with insufficient supination from late midstance through preswing.  Thus, this over pronation causing overloading of the plantar fascia and windlass mechanism, resulting in increased torsional forces and micro-tearing at it’s proximal calcaneal (and sometimes distal) attachments. This causes local pain, swelling and inflammation, particularly at the calcaneal attachment site, which is alleviated by rest, ice and analgesics. As we have shared many times now, this over pronation does not have to be a local cause, it could be necessary from insufficient internal rotation of the hip or from other factors.

In this study, the Right shoe upper was canted medially on the midsoles, believed due to it not being glued perpendicularly (as we often see inspecting a shoe from behind, especially Asics Kayano’s in our experience). The authors state they felt this contributed to excessive inward rolling of the right foot, contributing to overpronation.

The authors make the following recommendations about shoe inspection:

  • The shoe should be glued together securely
  • The upper should be glued straight (perpendicular) onto the midsole. The shoe, viewed from behind should have a horizontal heel counter and vertical upper
  • The sole of the shoe should be level to the surface on which it is resting (ie no medial to lateral motion should be present) You can test this by attempting to “rock” the shoe from side to side
  • The shoes should not roll excessively inward or outward when resting on a level surface (ie when rolling from P to A) You can test this by rocking the shoe from A to P
  • Air and gel pockets should be inflated evenly. This can be tested manually by pressing into them and checking for uniformity.

A nice rehab protocol is also outlined over a 4 week period.

Bottom Line: It pays to be shoe nerd. Shoes can help or hurt. We see manufacturers defects in shoes every day and tell clients to return the shoe; in fact some we collect  to use to show people. A rearfoot varus in a shoe will help to slow pronation. This may actually be beneficial for overpronators but detrimental for supinators. Some defects can be helpful but try and find defect free shoes. Stay away from “2nds” at cheapie stores and online specials. There is usually a reason they are being sold so cheaply. EVA’s have a shelf life and will break down over time. You must be able to not only recommend the appropriate shoe for your patient, based on their evaluation and gait analysis, but you need to inspect their footwear carefully and teach them to do the same.

The original shoe nerds….Shawn and Ivo

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Stage 1 of Correcting a flat foot, video demonstration.

Here is a case of a young man that was brought into us by his parents. Their concern was that their son was displaying what they thought was foot weakness. 

At the beginning of the video you can see that his foot progression angle is significant.  Certainly greater than the 10-15 degree “so called” normal range.  His arches are also somewhat collapsed. His knees were also displaying some hyperextension which is quite common with flat foot posturing.

This was his third visit into our office. He was given the corrective neuromuscular strategy that you see here and some specific exercises to help him get to this stage of correction.  The first stage of any correction is developing the awareness of what you are doing wrong (ie. become consciously aware of your incompetence). That was session one.  Session two focused on developing this corrective pattern, helping him find the skills to develop some conscious competence with a more normal foot stability skill pattern (endurance and strength still need to be added). 

Here you will see that, when queued, he immediately moves into a narrower base of stance (this will always happen when they can form a competent foot tripod, as you can see here).  In other words, the worse the foot collapse, the wider the feet will be positioned.  In his case, he now positions his feet under his hips and knees. 

You will also see the early success (after just 2 visits !) of a critical neuromuscular pattern.  He is showing some competence in holding the arch up and letting the toes move into flexion onto the ground.  Most flat footed children cannot separate “maintaining arch up, and moving into toes down”, rather they are into the pattern of “when the toes drop to the floor, the arch drops as well”.  This is a critical pattern (ability to hold arch up) to recognize and develop.  The child must develop the ability to independently flex and extend the toes on a static arch, while holding tripod,  before gait retraining can ensue.  This is mainly because the speed of gait and difficulty of single leg stance while displaying the correct pattern is just too much of a skill mastery issue. Often these pupils do not have enough hip frontal plane stability nor pelvic stability as well.

Also, note that he uses the skill of toe extension to help with arch height determination.  This goes right back to our blog posts last week on the Windlass Mechanism.  He is using the power of the windlass effect (toe extension) to take up the slack in the plantar fascial around the great toe metatarsal joint and thus pull the rear foot towards the forefoot (ie. raising the arch via this mechanism ! ).  Without a competent windlass a competent arch cannot be obtained (thus the ridiculousness of plantar fascial release surgery !).  Additionally, understanding the windlass and the effects of this simple video should give you insight into our success in quickly treating plantar fascitis. 

(addendum: also note at the end of the video that i ask him to collapse into his old pattern, this was after 30 minutes of corrective motor pattern exercises.  I laugh because in a solid posture that he shows at the end of the video, plus 30 minutes of new patterning, he found it difficult to find his old collapsed pattern.  This is a frequent occurance ! It gives you and the patient confidence that headway is being made.)

You must develop isometric, eccentric and concentric strength of the plantar intrinsic muscles that stabilize, raise, and control the lowering of the arch (as well as the arch controlling extrinsic muscles such as tibialis anterior and posterior among others) if you are going to make a difference in someones foot mechanics.  Just putting someone into a pair of ANY minimalist shoe (let alone barefoot) doesn’t guarantee strengthening of the foot or a remedy for a pair of feet like in this video. The process is a little more complicated than slipping on a pair of low ramp angle “shoes” and wearing them all day long…….in these types of cases all it does is raise their risk of injury or further foot incompetence down the road. 

For our fellow clinicians out there who are following us and trying to learn more about this kind of stuff……. wouldn’t your clinical world be nice if just prescribing a minimalist shoe would strengthen the foot in the correct pattern !?  We argue that, as in this kids foot, they would strengthen his foot in his poor postured patterns. So, we guess these companies are not lying when they say their shoes “strengthen” your feet, they just leave out the word “correctly”.

So, we do not argue with the point that going minimalist will strengthen your foot…… the question is “do you want to strengthen the correct pattern or a compensated one?”. 

here at The Gait Guys…….we know which pattern we want to strengthen.

We remain strong advocates that not all feet belong in minimalist shoes…… at least not initially, and some, never.  It would be nice if just slipping on a shoe could fix all of your foot problems, but it just isn’t that easy.  This is the topic no one is talking about, except The Gait Guys ……… because it doesn’t sell shoes.

There is much more to it than this video shows……. but we have to start somewhere.  Educating you with the issues we feel passionate about is the first step sometimes.

We remain…….obviously passionate………..

Shawn and Ivo….. The Gait Guys

The Windlass Mechanism of the Plantar fascia. What is a Windlass anyway?

After yesterdays post, we thought we might provide more insight to the Windlass mechanism and low and behold; we found AN ENTIRE PAPER on it! Wow, were we thrilled since there is not a ton of decent stuff out on this topic (yes, we are a little geeky, but then again so are you if you are reading this !).

A Windlass is the tightening of a rope or cable around a pivot point. The plantar fascia acts like a cable between the calcaneus and its distal insertion into the proximal phalanyx at the metatarsal phalangeal joints. When the toes are dorsiflexed (as in forefoot rocker from yesterdays post, see bottom diagram above), the heel and toes SHOULD become approximated, as the plantar fascia shortens from its winding around the metatarsal head, contributing to supination of the foot.

To be accurate, this concept of the Windlass mechanism is quite complex because the dorsiflexion of the great toe also shortens the length of the flexor hallucis brevis.  And we know that the sesamoid bones under the big toe are embedded in its tendon. Their repositioning as the Windlass engages will drive the sesamoids under the metatarsal, elevating it, and shift this joints eccentric axis.  But this is a complex story and post better left for another day.  Simply put, this is a complex joint, do not let anyone fool you otherwise.  Don’t beleive us ? Ask any bunion (or God forbid a fusion) surgery patient how they are doing.  You will get the point then. 

Here’s the link to the article (we know you want to read it ! )

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC385265/

The Windlass Mechanism. Just another fascinating foot fact from The Gait Guys.