Marathon Season Injuries: Part 3

In our last article we discussed achilles and plantar fascia pain. In this latest article we discuss calf injuries.

Research into calf injuries is limited. There have not been the number of studies that we see in other areas of injury, such as the hamstring. With this in mind a recent systematic review by Brady Green and Tanya Pizzari out of Latrobe University showed that there are only a few confirmed risk factors that increase calf muscle strain injuries. These are increasing age and previous calf muscle strain injuries.

Why is this?

There are a few theories as to why increasing age increases your risk. The main theory that is put forward is the change in muscle changes associated with age. These include sarcopenia (more likely as hormonal changes start >40 years of age) as well as the change in the distribution of muscle fibre type as we age. Unless trained to maintain fast twitch fibre distributions, there is a general tendency to lose fast twitch fibre type cross sectional area. Given that the explosive nature of most running based sports, the reduction in the explosive characteristics of the calf complex, leaves it susceptible to damage under tight force activities such as jumping, accelerations or change of direction.

So if you are having calf trouble with distance running, what can you do?

As discussed in previous blog on achilles pain biomechanics and training load play a vital role in the development of calf complex overload. Refer to the article here to see relevant discussion on both topics. With regards to the calf characteristics that we will discuss to address there are two main areas that need to be managed with a third item that alters the stress of the main areas to be addressed. These are increasing force producing capability. Increasing velocity capability under high force and the third factor is doing these tasks under stretched conditions.

The body is an intelligent and malleable organism. So it is of no surprise that if we gradually expose it to tasks that stress these characteristics, high force and high velocity and then eventually both with the inclusion of different lengths of tissue, we will create the required changes to make the calf robust.

What does this look like?

Most people will look to increase strength first and this is relevant if it is assessed that calf strength or muscular endurance is lacking (Tip: to measure muscular endurance of the calf attempt single leg calf raises on a step in a strict, controlled manner. If you cannot do >20-25 you may be lacking calf muscular strength and endurance) . Tasks such as calf raises both single and double leg with knee straight and bent in a progressive loading fashion (adding weight, can be as high as 1-1.5 times BW) is likely to significantly increase you calf strength. This will start to alter the reduction in cross sectional area loss of fast twitch fibres if you are lifting at a high intensity.

To address the high load, high force tasks jumping (plyometric tasks) add significant benefit. These can start as simple as double leg single vertical jumps , then progress to continuous bouncing jumps on the spot and then to jump tasks that require you moving forward (horizontally) both at speed and trying to cover distance. These tasks start to alter elastic (bouncing properties of the body) abilities and will start to increase the ability for the fascicles to withstand fast stretching tasks.

Once you are mastering these and do not have any issues with these jumps further emphasis can be placed on creating high force, high velocity stress on the calf at longer stretching lengths. This would look like sprint accelerations or deceleration. To add further resistance to these you can utilize hills or sleds to increase the force required to stabilize the ankle as well as propel the body. Obviously these tasks can be added earlier at a lower intensity, such as hill or sled walking or less than maximal speed runs. The increased length and speed has been shown to increase the fascicle length of muscle fibres, particularly in relation to hamstring muscle studies in sprint tasks and high velocity eccentric loading.

This by no means addresses everything to do with calf strain injuries or reducing your risk of calf injuries, but if you have gradually added these into your training plan it will increase the robustness of your calf and hopefully protect you from further calf strains.