What is Pronation?
If you are a runner you will have no doubt heard the term ‘overpronation’. You may have been fitted for trainers and told you need support to help reduce your ‘overpronation’ but have you ever stopped to consider what this actually means?
Pronation is a normal movement as the foot makes contact with the ground and rolls inwards. This unlocks the joints in the foot to help act as a shock absorber. The front of the foot splays out and the ankle joints bends to allow the body to come over the foot. It is followed by supination when the joints in the foot lock, the foot rolls out onto the lateral border providing a solid base to push up from.
Much research has concluded that there is no ‘normal’ amount of pronation as it varies between individuals as does the anatomy of the foot. So if there is no ‘normal’ amount of pronation, how can we have an ‘abnormal’ amount?
One of the key muscles that supports pronation is Tibialis Posterior. This muscle on its own would extend the ankle (pointing the toes) and invert the foot (turn the sole inwards). However during pronation its role is to control the movements of the ankle flexing and turning out. This requires the muscle to work eccentrically. A normal healthy Tib Post, along with the calf muscles can happily control the pronation as we propel ourselves along. In some individuals there are structural issues which can lead to a lowering of the medial arch (flat feet) and poor health in general, obesity, lack of range of movement can lead to the muscles being unable to support the movement potentially leading to foot problems. If the foot isn’t working correctly then this can also have an impact further up the chain leading to problems with the knees or hips. The body is a finely tuned machine that works in synergy, if one part fails it has a knock on somewhere else. Although incredibly adaptable it needs time to adapt and often its the sudden change in activity that leads to the development of problematic symptoms.
When it comes to running the degree of pronation doesn’t change significantly but what does change is the speed that the pronation occurs. As the foot hits the ground there is more force and the foot moves more quickly into pronation and then subsequently into supination. The muscles that support pronation can be subject to greater load than they can handle, leading to problems around the foot, ankle or arch. The Tibialis Posterior can be become fatigued from trying to slow down and control pronation and this can lead to pain on the inside of the ankle. Trainers that aim to correct the amount of pronation will provide some stability around the inside of the foot and arch but ultimately its not addressing the underlying issue. Having good, strong lower leg muscles is important for runners and this will only be achieved by strengthening exercises.
Running form can also impact on foot mechanics. New runners very often overstride as they don’t use there posterior muscles to drive them forward. This over stride causes a breaking force that the body then has to overcome. It tries to overcome this by using the calf muscles to push the body up over the foot. This leads to fatigue in the calves which is often experienced as tightness. It also put excess pressure on the smaller muscles such as the Tibialis Posterior. Overstriding is also linked to a low cadence which means the foot is on the ground for longer than it should be. This means the foot is in pronation for longer than it should be so the muscles that are trying to control pronation (Tib Post) are overloaded. Pelvic stability is another important factor to consider when thinking about pronation. If the muscles around the hips are too weak to stabilise the pelvis when the foot lands on the floor this can cause the knee to drop in to the midline which can lead to more load into pronation.
So the term ‘overpronation’ in itself is misleading. The real issue isn’t the degree of pronation (remember we all pronate to different degrees) it’s how we deal with the pronation. If you cannot control the pronation and continue to load the foot and soft tissues beyond what they can tolerate, something will give and as with any chain it’s the weakest link.
The key to preventing pronation leading to injury is to strengthen up the entire chain. In next weeks blog I’ll go through some key exercises to strengthen your hips and legs. Running won’t make you stronger so its important to add 2-3 sessions of strength and conditioning if you want to improve your running and reduce your risk of injury.
Pronation isn’t a bad word, it’s not something we want to prevent, so next time you are thinking of spending crazy amounts on a pair of trainers that prevent overpronation stop and think. You may be able to correct problems by simply adding in some strength based exercises. The video below of Haille Gebrselassie is well worth a watch (quality isn’t great). The coach explains pronation and you almost wince every time his foot strikes the ground
If you have any questions about pronation or running injuries please get in touch or comment below. You can sign up for the weekly newsletter via the website