Stretching out

We all know that stretching should be an integral part of our training programme, but how many of us ever actually spend the time working on improving our flexibility? Pure Sports Medicine’s Chris Wilkes (www.puresportsmed.com) explains just why flexibility is such an important part of training and injury prevention – and suggests some tips to keep you running healthy and strong
Adequate flexibility is just one of the requirements of injury free and enjoyable running but it’s often one that causes confusion among athletes of all types, from professional to recreational. How much flexibility is enough? Can we be too flexible? How do we best improve our flexibility?

What does the research tell us about flexibility and injury prevention?

As you would imagine, there is a vast amount of research covering all sorts of angles on this subject but there are a few points that seem to be worth considering. Firstly, it seems that symmetry is a more significant factor than overall range. This means we need to be assessing and working to correct imbalances between our left and right sides in training and warm up strategies. Secondly, evidence is fairly consistent on the fact that our flexibility needs are very task specific, so we need to carefully analyse what is required of running and focus on these areas. This follows on to our third point that general hypermobility or excessive flexibility over and above what is required often leads to an increase in injury prevalence in runners rather than giving us any advantage.

Running demands

Let’s first look at the task of running and see what the biomechanical requirements of the human body are to perform this task successfully. We can break down the movements of running into three planes of motion:

1. The sagittal plane: this is the one we probably see most easily when looking at runners. It is the plane that comprises the forward and backwards motions. If we take the hip, for example, the movements here are flexion when the leg moves forward or upward towards the chest and extension where the leg moves backwards. For most runners, it’s this extension movement that requires attention. This may be as a result of a number of factors, not least the time we spend sitting with the hips in a flexed position.
   
   So what happens if we have reduced hip extension? Well, we may simply see a reduced stride length but often the consequences start to manifest as changes in posture and movements elsewhere in the body. One of the most common compensations we see is excessive extension in the lower back. The lower back is designed to allow us to extend and, in fact, having just the right amount of extension here really helps us load our abdominal muscles effectively.
   However, it becomes a problem when extension becomes excessive and starts to cause extra loading on the joints in the base of our spine or long-term tightness in the muscles in this region. How many of us have felt this fatigue or pain in the low back during runs? Well the answer may be in the hips! The effects of reduced hip extension are not limited to the lower back; we may also see issues arising in the upper back and neck causing tissues here to be overloaded and possibly injured. Further down the chain, a lack of hip extension may rob us of the ability to get good dorsiflexion at the ankle (when the shin moves forward over the toes). This may prevent us being able to really load our calf muscles effectively and be efficient when running.
   
   
2. The coronal or frontal plane: this is the plane that comprises side-to-side movements, for example, lifting your arm straight out to the side. Perhaps we don’t think of this as being a crucial plane of movement for running when the goal is usually to go forward. However, many of the muscles that help to propel us in that forward direction need to be loaded (stretched slightly) with this side-to-side movement to make them more efficient. A good example of this is the calf muscles. When our foot hits the ground, whether we are a heel striker or more of a mid foot striker, one of the initial reactions of the foot and ankle to this impact is to be loaded in the frontal plane. This is a component of the movement pronation which I’m sure many of you have heard about when purchasing trainers or getting injury advice. This frontal plane motion is important for absorbing the impact at ground contact and helping the calf muscle to then contract concentrically to produce the force required to propel us forward.
   
   So what does this have to do with flexibility you might be thinking? If the joints in your foot and ankle don’t have the ability to move through this motion (which is common, particularly if you’ve had and old ankle sprain or two that have never been fully rehabilitated) then your calf muscles may be unable to really function most effectively. You may even develop issues with muscles and bones in the lower leg which are having to deal with all this extra force. Clinically, it is not uncommon to see people with poor frontal plane control developing shin splints and stress fractures of the tibia.
   
   
3. The transverse plane: maybe the most neglected plane of the three, the transverse plane comprises the rotational movements (think throwing the discuss or winding up for a big tennis backhand). Perhaps the best way for us to see the transverse plane would be if we could look straight down on a runner from above; if we did this we would see that with every stride we have the pelvis and the shoulders going in opposite directions which enable all the muscles in between these points to be loaded eccentrically (lengthened) and then to concentrically contract and power us on to the next stride.
   
   So we can see that it becomes very important for us to have adequate range of rotation through the lower and mid back regions and it doesn’t stop there. While we’re running along and our whole upper body is rotating left and right in a rhythmical fashion most of the time we are looking straight ahead to see where we are going. It may seem like the neck is fairly stationary, but, as we look a little closer, we find that we actually have lots of rotation going on here to allow us to simply keep our eyes focused in front of us. So when you’re thinking about which areas to test for flexibility be sure not to neglect the neck - it could be that missing link to getting the most out of your core strength!

(Pic of abdominals with torsion going through them)

To sum up here are a few tips to help you on the way towards optimising your flexibility for running and preventing injury:

1. Start by self-assessing or, even better, getting a skilled professional to assess you in the regions that matter most for runners: feet, ankles, hips, and spine.
2. Assess these in positions that look and feel a lot like running itself (hint: you should be usually be standing up for this)
3. Assess these positions and regions in all three planes: sagittal (forward and back), frontal (side to side) and transverse (rotation)
4. Check for symmetry between your left and right sides – work on addressing imbalances with your stretching programme
5. If you are generally very flexible consider, whether or not you actually need to increase your flexibility at all for running - time may be better spent improving other attributes such as strength and stability.
6. Finally, if you are stretching regularly and not seeing results you might need further assessment to find out the underlying cause of your inflexibility. The structure of your joints, the ligaments and joint capsules and even your nervous system may all affect your flexibility and sometimes these need addressing in order to get the flexibility you require.

(Pic standing hip flexor stretch position)