The foot in running is a massive subject and a hotly debated one when it comes to running and running injuries. Most recently all the take has been regarding barefoot running and I’m sure the pronation/overpronation argument will also continue to rage on for years to come.
The Foot in Running: Movements at the Foot
There are 26 bones in the foot. The rearfoot bones – Calcaneus and Talus; the midfoot – Navicular, Cuboid, three cuneiforms; 5 metatarsals (long ray bones leading up to the toes) and 14 phalanges (small bones in the toes).
This means there are 33 joints and more than 100 muscles, ligaments and tendons! So, it’s a pretty complicated piece of engineering!
The majority of movements at the foot (other than the toes which flex, extend, adduct and abduct) are small, gliding movements between each of the bones, which altogether create a larger motion. The Subtalar joint, between the Calcaneus and Talus is the most mobile and is responsible for the movements of Pronation and Supination (also called eversion and inversion respectively).
The Foot in Running: Supination and Pronation
Pronation is a word you have probably heard before and refers to the rolling in and arch flattening motion which happens at the foot. Supination is the opposite of this movement, where the arch raises and the foot becomes more concave.
Both of these movements are perfectly normal and necessary for a normal gait cycle. Pronation allows the foot to mould to the shape of the surface beneath you, absorb the shock after impact and transfers the weight from the heel at landing to the big toe when taking off. Supination allows a more rigid foot at both impact and push-off, to provide both a stable base and a rigid lever to allow efficient energy transfer.
The problems only come when the foot over-pronates or over-supinates (sometimes called under-pronation – just to confuse us!). By far the most common scenario is overpronation.
If you aren’t sure if either of these apply to you, then I would advise having a gait analysis.
Excessive pronation, in terms of either the amount of movement, of the speed of pronation can be a cause of numerous injuries, from Achilles Tendinopathy, to Patellofemoral Pain Syndrome and back to Plantar Fasciitis to name just a few!
The reason that overpronation causes injury varies depending on the injury in question. With PF, the fascia is repeatedly overstretched. Or with PFPS excessive pronation causes an inward rotation force on the lower leg which translates up the Tibia to the knee.
Test – Stand up with bare feet and lower legs, on a flat surface. Roll your foot inwards to lower the arch towards the floor. Observe the movement at the lower leg! Then reverse to raise the arch so your weight is on the outer foot – the leg rotates back around the other way. Imagine that happening with every step!
Overpronation can be corrected using arch support insoles or orthotics which are placed in the shoes. Motion control running shoes have this arch support already built in. Strengthening of the Tibialis posterior (which supinates the foot) along with eccentric Peroneal strengthening to control the speed of pronation, can really help too. Another thing to consider is your calf muscle flexibility. If you calf muscles are tight and your range of Dorsiflexion is limited, then the foot tends to pronate more to get a few more degrees of movement.
Oversupination is far less common that overpronation. It means the weight stays mostly on the outer part of the foot and the foot stays rigid with a high arch. This can lead to injuries such as stress fractures of the foot bones and shin splints due to not absorbing the shock when landing on the heel.
Generally, when looking to reduce the problems caused by oversupination, cushioned running shoes are recommended. There aren’t many off-the-peg insoles available (that I am aware of) which are designed for oversupination, but a podiatrist or similar would be able to make custom made orthotics. Strengthening the Peroneal muscles should help to increase pronation.
The Foot in Running: Barefoot Running
Barefoot running has been a hot topic in the last few years due to claims that running without shoes (or in minimalist footwear which mimics barefoot running) can reduce the risk of injuries.
There is definitely some science behind the claims and also some history – running barefoot has been the way of many cultures for hundreds of years and they don’t seem to have suffered the same injuries as we in the western world do now we wear ‘technologically advanced’ and cushioned running shoes!
Running barefoot forces you to shift your point of impact from the heel onto the mid or forefoot to avoid pain when landing. It is this shift that is believed to be beneficial.
I get asked for my opinion on this quite a lot, so here it is!
I don’t think that everyone should start running around with no shoes on! The last piece of research I read on the subject demonstrated that whilst running barefoot, or with a mid / forefoot strike can reduce your risk of knee injuries such as PatelloFemoral Pain and IT band syndrome due to reduced forces at the knee and less frontal plane motion (ad/abduction).
However, the same research highlighted that those who ran with a heel strike demonstrated reduced forces on the Achilles tendon and so reduced rates of Achilles tendinopathies, as well as other injuries related to calf tension.
So, from an injury prevention point of view, my opinion is that “if it ain’t broke don’t fix it”. For those who already have a chronic knee injury that they are struggling to overcome, a reduction in heel strike force may be worth considering.