Foot Orthoses and Peroneal Activation

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Neuromuscular Activity of the Peroneal Muscle after Foot Orthoses Therapy in Runners.
Baur H, Hirschmüller A, Müller S, Mayer F.
Med Sci Sports Exerc. 2011 Jan 12. [Epub ahead of print]

 

Just given this article a glance over - nice to see a study performed on symptomatic individuals for a change. Just a few thoughts/questions:

- All the subjects had current lower limb overuse injuries, but it does not appear that any were suffering with peroneal tendinopathy. Would an increase in peroneal activity be appropriate/desired in these individuals? I assume not.

- It states that all orthoses were 'individually fitted and prescribed based on dynamic plantar pressure distribution' but then a few sentences later reports that all devices had 25mm medial longitudinal arch support and a 3mm lateral forefoot post. The devices they used in the study were called 'Movecontrol' which appear to be a German company. Anyone have any experience of them?

- Subjects in the study had to exceed a weekly running distance of 32km to be included. Those that were randomised into the orthoses group were asked to wear them in a neutral shoe. There did not seem to be any discussion of the shoes they had worn for all of their previous running prior to the study. Would it have made more sense to record pre and post intervention data in their own footwear?

- No blinding of the subjects. It would have been very clear to them whether they were in the treatment or the control group. Hawthorne effect?

 

This study certainly has its strengths (sample size, method of processing and reporting EMG data etc). However, I find it really puzzling that they only recorded EMG data from peroneus longus in individuals that report symptoms of Achilles tendonopathy, patellar tendonopathy, PFPS, plantar fasciitis, ITB syndrome, tibial periostitis. I can't think of peroneus longus as a major contributing factor in too many of these conditions (except maybe ITB syndrome). They then go on to describe how these foot orthoses would increase ankle stability due to increased peroneal activity. None of these patients have reported any problems with ankle instability to begin with. This seems a little like 1 + 2 = 10!

Additionally, it is a flawed notion that increased peroneal activity due to foot orthoses use is indicative of a more stable ankle. To me, the most obvious reason for increased peronal activity with orthoses use, would be due to the increased ankle/rearfoot inversion moment. This may well induce a feedforward mechanism of neuromuscular control (indeed I think it does), however it is more than likely in anticipation of a more laterally unstable landing.

I have further questions about their theory of sensorimotor control. Again, the more likely explanation is that alterations to internal joint loading will cause a reflex response in joint mechanoreceptors and muscle spindle apparatus, not cutaneous receptors.

In my opinion, this study could have been so good. However, lack of data from other muscles acting on the lower limb, combined with strange interpretation of results, leaves me a little dissapointed.

Cheers

 

:good:

nice one

Dave Smith

 

Ian,

Do you a copy of the article you could send my way please?

Cheers,

Dave

 

It's on my machine at home big man - will send over this evening

IG

 

Cheers fella - greatly appreciated!

D