Anterior Shin Splints common causes & rehabilitation

Anterior Shin Pain (Shin Splints) common causes & rehabilitation by Gary Lewis, (Rehabilitation Specialist, OSSM Dip  

This is a common injury that many people suffer through walking or running. It is prevalent in a military population during activities such as  'weighted marches' but the question is why?

We can apply either a bottom up or top down approach in order to recognize the causes of this annoying problem. I also suffered with this for many years as a youngster in the army but like most people I gritted my teeth & got on with it.

In essence the area around the front of the shin (tibialis anterior) becomes overloaded, it is prone to fatigue.
Other terms people use to describe symptoms include:
- Burning
- Heavy
- Slapping uncontrolled foot drop of the affected limb.
- Ungodly pain

As soon as the physical activity is over symptoms tend to settle almost immediately.

So here's the reasoning using a 'bottom up' approach.
The body has two types of muscles these are either postural or phasic.
Postural muscles have a high blood supply utilising slow twitch fibres and are therefore able to work for long periods. The muscle fibres fire alternately so that there is a constant contraction. The main postural muscle of the ankle complex is the Soleus, a member of the calf group or plantar flexors.
The soleus is a bit of a bugger it is also known as the second heart! Not only does it help us to push off our toes (imagine a calf raise) but It also helps to drive blood from the feet back up toward the heart. It works constantly to ensure that we are able to stand up, without it we would fall over. Being such a busy muscle it is prone like other postural muscles, to shortening.

A simple test to assess your Soleus length is the Knee to Wall assessment. A normal Soleus will have a range of at least 8cm, of course de-generative changes to an ankle joint will have an affect on the muscle length aswell.
If Soleus is short then the opposing major muscle, in this case Tibialis anterior will be forced to lengthen to compensate. This places excessive strain on the muscle which has to work very hard to pull the ankle up against the powerful calf group!
It is here that we see a dysfunction occur!

Tibialis anterior is a phasic muscle it's function in life is to decelerate the speed at which your foot strikes the floor.
It utilises fast twitch white muscle fibres (type 1 & 2). Unlike slow twitch fibres, fast twitch are prone to fatigue very quickly as they have a poor blood supply. (Although tibialis anterior has modified some of its fast twitch fibres to house a greater blood supply)
Either way tibialis anterior can't resist the strain the Soleus places onto it and has to do some recruiting elsewhere to get the job of lifting the ankle upwards done!

It calls upon smaller muscles to contribute in particular we see increased activation in the muscles that lift the little toes and the big toe up known as the 'toe extensors'. The result of this problem is really overdeveloped extensor tendons in the feet and clawed looking feet.

The answer to the issue we have just described is to:
- Apply self- administered fascial release using a foam roller or similar apparatus.
- Seek Massage therapy or Acupuncture as these are far more effective.
- Employ regular Flexibility of the Soleus using a slant board as much as 3-5 times per day, holding stretches for 30-90 secs or until a natural release is felt will also help.
The second main cause of anterior shin pain requires an understanding of how we walk or run combined with a top down approach. The walking dysfunction we will focus on now is known as 'toe clearance'.

So here's the reasoning using a 'Top Down' approach
During walking and running the body Is in either a stance (foot on floor) or swing phase (leg off floor). As the swing phase of gait commences a normal fully functional Iliopsoas flexes the hip up, causing the knee to bend and ankle to lift off the floor. Inadequate strength in this critical hip flexor to
effectively 'drive the thigh' upward as the limb accelerates in the swing phase, will see an individual barely clear the floor with the foot. On occasion the affected individual may report 'stumbling' 'tripping' during events.
The body compensates for the weakness by forcing the muscles of the shin (tibialis anterior or toe extensors) to work even harder to lift the ankle. Again leading to immediate fatigue and pain.

The answer to this issue is to strengthen the Iliopsoas through maintaining neutral spine and practicing hip flexion on a single leg or in back lying. I prefer to do this with a lightly colored theraband for resistance. Controlled repetitions of 10-15 @ 2-4 sets with a tempo of 2-2-2 will help.

I hope you have enjoyed this blog, please feel free to contact me via PM for further advice or to book a assessment should you require any rehabilitation, soft tissue work or acupuncture.