Thursday, December 29, 2011

Overpronation in Runners

“Overpronation” has been some sort of buzz word in the running community for a long time, but is generally a meaningless term. It is widely used to wrongly prescribe a specific running shoe (ie motion control). The real problem with the term is that it is a substantial oversimplification of what is actually happening to the foot and the use of the term seems to have made experts in it by some health professionals, running shoe sales people, coaches and even runners who have no sort of medical or related qualification. The blogosphere is also full of non-experts pontificating on myths of overpronation. It is easy to see that they have no real understanding of biomechanics and foot function and what they write is easy to deconstruct. There are numerous reasons why a foot may overpronate, so to advocate one method to treat overpronation over another is just plain ignorance of what the causes of it are. Muscle strengthening will only correct overpronation if a muscle weakness is the cause. Muscle stretching will only correct overpronation if a tight muscle is the cause. Gait retraining will only correction overpronation if there is an abnormality in the gait amenable to gait retraining. Foot orthotics will only correct overpronation is there is an alignment issue with the bones. If you have overpronation, do yourself a favor and see someone who actually understands what it is, rather than listen to the unscientific pontifications of self-proclaimed gurus who just happen to have a blog. For more detail on this, I blogged about it here. There are so many overpronation myths to bust and so little times to deal with them!

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Wednesday, December 21, 2011

Navicular Stress Fracture

Navicular stress fractures are a diagnostic challenge and the existence of the so called “N spot” over the navicular is an important diagnostic suspicion. X-rays are not always helpful with a significant number of false positives. There are no short cuts with a navicular stress fracture, the time non-weightbearing away from sport is a minimum of 5-6 weeks. There is no way around this. I have recently spoken to a couple of colleagues who had to deal with athlete with this and they were looking for ways to avoid that. There is no way. The outcomes and success rates and the return to sport for a navicular stress fracture, regardless if it is a surgical or conservative management plan seem to be about the same. The athlete has to be told: no weightbearing for 5-6 weeks. Find a non-weightbearing activity for them to keep going.

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Tuesday, December 13, 2011

Running With a Cadence of 180 Steps a Minute

The concept of runners shortening the stride length and increasing the cadence to 180 steps a minute has been coming up as a concept a lot me recently. I am not sure what to make of it. Some prominent coaches and running form experts are advocating it to reduce the risk of injury. At the same time a number of sports scientists are dismissing it as not valid. Most runners tend to naturally adopt a running form that is the most metabolically efficient for them. Any change to that tends to come with a metabolic cost. Those that advocate it are very passionate abut it, but as we know that the more passion there is in defending a theory, the less likely there is to be any evidence that supports it (Paynes First Law). I am certainly seeing injuries in those runners who use a 180 cadence, so I going to wait until the science tells me which is the better way to go on this one.

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Wednesday, September 14, 2011

Does the Circulation Booster Work at Improving Circulation?

We have all seen the adverts for the Circulation Booster, but can it really boost the circulation? Surely the claims “as seen on TV” and the reliance on testimonials in the marketing should be enough to set off the ‘snake oil’ alarm bells. There is certainly no good scientific data to support its use at improving circulation to the lower limb and the Therapeutic Products Advertising authority in Australia forced the company to modify the claims that they made. A similar ruling was given by the Advertising Standards Authority in the UK.

So how is the Circulation Booster supposed to work?

When we are walking the rhythmic contraction of the muscles in the lower limb act as a muscle pump to help pump the blood back up to the heart. This is an important way to stimulate the venous return part of the circulation. The idea behind the Circulation Booster is to provide a small electrical stimulus to the bottom of the foot while sitting to gently stimulate the muscles to contract and thereby help the venous return to the heart. This has nothing to do with the arterial supply or the about improving (or “boosting”) the amount of circulation down to the foot and lower limb!

So, at best, the Circulation Booster may help blood go back up the veins, but the blood supply down to the feet and legs come via the arteries and it won’t affect that! This maybe help prevent DVT and other thromboembolic events… but so will walking and this will be a whole lot better for people than sitting with their feet on the device. There has been some research that has shown some improvement in the venous parameters, but that is NOT the arterial circulation (funny how the company promotes these scientific studies, but do not point out they are on the venous side of things and not the arterial side!)

Going for a walk around the block is going to get that venous muscle pump working harder and do a lot more good for the venous circulation that sitting with the foot on the Circulation Booster. Going for a walk (ie gentle exercise) is going to help fitness, general well-being, prevent osteoporosis and actually improve the arterial circulation. So what you going to do? Sit down for 30 minutes on the Circulation Booster or go for a 30 minute walk. Which one is going to help your circulation more? Which one is going to hurt the wallet more?

Until I see some credible data, think placebo effect when people say they help.

See the Podiatry Arena discussion on the Circulation Booster.

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Thursday, September 01, 2011

'Top of Foot Pain' Management in Barefoot Runners

Despite all the propaganda that barefoot or minimalist running is better due to less injuries occurring, it is now becoming increasingly clear that it is not the way to get less running overuse injuries. Just check any barefoot/minimalist website and look at all those looking for advice on their injuries! Just ask any of the health professionals who treat a lot of running injuries. Most will tell you of the barefoot running injury epidemic that they are seeing. There is no doubt that there are some who have successfully transitioned to barefoot or minimalist running who now claim to get less injuries, but there are also those who are getting more!

One of the more common injuries being seen is what has become known as ‘top of foot pain’, which probably is dorsal midfoot interosseous compression syndrome (DICS). The pain of this is usually over the dorsal midfoot area. The cause of this is when the dorsiflexion moments of the forefoot on the rearfoot are higher than the plantarflexion moments, resulting in the dorsal jamming. Forefoot striking has greater forefoot dorsiflexion moments of the forefoot on the rearfoot than does heel striking. I have been involved in the management of a lot of ‘top of foot pain’ now in forefoot strikers or minimalist runners and here is my approach to it:

1. Firstly you really need to understand the runners views on barefoot/minimalist running and just what they are prepared to do. By this I mean how acceptable of different interventions are they to be; are they training for a specific event (to get an indication of the ‘urgency’ to get over the problem); what sort of time frame they have; etc

2. Of course we use the RICE principle with this injury like any others in the short term and make modification to the training regime to manage it.

3. The best way to manage ‘top of foot pain’ in the short term and long term is to decrease that dorsiflexion moment. How can you do that?
  • a. If you follow some of the advice on the barefoot sites, you need to change your running form or gait somewhat and try to ‘retract’ the toes. As this will put a plantarflexory load on the metatarsals which will reduce the forefoot dorsiflexion moment. Most runners find this difficult and often it does not reduce the load enough for healing to occur (it may work better in the long term once the problem is treated).
  • b. Low dye strapping, correctly applied to plantarflex the forefoot in such a way that it decreases the dorsiflexion moment will work brilliantly in the short term, but is not a good long term option. Correctly applying the low dye tape is crucial.
  • c. Foot orthotics are easily the best way to reduce that dorsiflexion moment, however they have to have the right design features to do that or they are not going to work. All foot orthotic failure I have seen in those with ‘top of foot pain’, either did not decrease that forefoot dorsiflexion moment or even increased it!
  • d. Depending on where they are at, they are also probably better off getting back to heel striking if they can to help reduce those forefoot dorsiflexion moments that are higher in forefoot striking.
  • e. Ankle joint dorsiflexion also need to be checked and often a fibula mobilisation is needed to get that going properly.
  • f. Increasing muscles strength may be a longer term option to reduce the dorsiflexion moment. However, as the joint moments are high, the muscles are already having to work hard because of that and are probably already really strong. The problem is the lever arm that the muscles have to the joint axes of rotation.
  • g. A windlass dysfunction can also be an issue in creating higher forefoot dorsiflexion moments, so some sort of intervention to preload the hallux to get the windlass active sooner can be helpful (this can easily fit in minimalist running shoes)
4. However, depending on some of the answers to the discussion in (1) above, as too how acceptable some of these interventions are, for example:
  • a. If they are more ‘purist’ in their views on barefoot/minimal, then they are not going to want to use foot orthotics or transition back to rearfoot striking (even in the short term). In this case, the running has to be cut back to level that is tolerable and a slow and gradual build up to allow the tissues to adapt to the load (ie adapt to those higher forefoot dorsiflexion moments). I happy to work with them on this, but they have to realise that in some people the moments are so high, that the tissues may never be able to adapt to the load and changes to the running form or gait. In this case other interventions will be needed if they want to get over it. I also point out that it will be harder and take longer to get better without the use of heel striking and/or foot orthotics.
  • b. If they not so ‘purist’ then I will get them into foot orthotics and, if they, can get them back to heel striking in the short term. Once they are better and back to their normal training routine we then decide what to do in the longer term. Ideally they will transition back to forefoot striking (if that is there wish) and away from the foot orthotics. This has got to be a planned process and done incredibly carefully (as the previously injured tissues are very prone to re-injury) and gradually. In some, that forefoot dorsiflexion moment is so high, there is no way that it can be lowered with a gait change and so high that the tissues can adapt to that load. In which case the heel striking and/or foot orthoses are going to have to be a long term option
Just why are the joint moments causing this problem so high? I think the most likely reason is the variations that occur in joint exes positions and the lever arms the bones and tendons have to that joint axis.

‘Top of foot pain’ is common in forefoot strikers (barefoot/minimalist runners). Understanding the role that the higher joint moments play in it guides the short and long term management, as well as the attitudes to forefoot vs rearfoot striking and the role of foot orthoses as a short or long term option and the issue of the magnitude of the moments and if the tissues can adapt to those moments or not.

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Wednesday, August 10, 2011

Do shoes cause flat foot in children?

There have been a number of previous studies in children in African countries that have shown a high correlation between flat foot and the wearing of shoes. This often gets touted as the shoes caused the flat foot and is used by those with an agenda to promote barefoot. However, that is not what those studies showed. All they showed was a correlation. Correlation does not mean causation

The studies could be interpreted several ways:
1. The wearing of the shoes did indeed cause the higher incidence of flat foot
2. Those with a prior flat foot wear shoes more often as the feet feel better wearing them
3. Those that wear shoes more often walk on harder surfaces and it is the harder surface that is responsible for the higher incidence of the flat foot, and not the shoes
4. Etc

Those with an agenda, clearly like to push option one as to what they think the studies have shown. Those without an agenda are open to all the options as an explanation of the results of those studies.

Now we have a new study on a population of children in Nigeria that has taken the analysis of these types of studies to a new level (see discussion: Flatfoot not related to footwear in Nigeria study) in which they used a more sophisticated analysis and controlled for some other variables. They concluded that the footwear was not a factor in the development of flat foot.

Don’t get me wrong, I have no doubt that footwear can and does cause a lot of problems, its just that the studies referred to above cannot be used to imply that wearing shoes in children cause flat feet.

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Sunday, May 29, 2011

Growing Pains in Children

Just have been having to deal with the issue of growing pains in the children. Growing pains in children have a very specific definition – its unexplained pain usually at the back of the knee and upper calf muscles that occurs at night. The cause is thought to be fatigue and sleep related, so is probably a biochemical problem. The real problem with the term growing pains is that any leg pain can often be written off as being a “growing pain” and they will grow out of it. There are several potentially serious (and not common) that cause pain in the leg. This means that every leg pain in the child is not growing pains and must be checked out. I only raise this as a child I know was repeatedly dismissed as having growing pains and it turned out to be an osteosarcoma. If the pain occurs in the day time or in the bone and is not relieved by gentle massage, then its not growing pains.

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Sunday, May 01, 2011

Manipulation for Cuboid Syndrome

Cuboid syndrome is an interesting condition with many different understanding about what exactly it is; what causes it; and how to treat it. Everyone seems to have an opinion on cuboid syndrome. Is it a subluxed cuboid? Or is it just a strain of the ligaments about the joints the cuboid is involved in. Opinions are also divided on the value of cuboid manipulation. For some it’s the only treatment, for other cuboid manipulation is dangerous if not done properly.

Personally, I actually have no idea exactly what cuboid syndrome is. It does seem to respond to strapping foot orthotics and gentle manipulation. The manipulation does seem to work some times, but not at other times.

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