Pronator or Supinator?
Undoubtedly, I would say this is one of the most common questions among runners , and yet most of the time we don’t know what it means or how it can affect the biomechanics of our movement.
In this article, we’re going to answer the most common questions on the subject.
What is pronation and what is supination?
These are two terms that refer to how the foot is supported and the relationship between the ankle and subastragalic joints.
The subastragaline joint can make movements in all three planes of space so that the anterior part of the calcaneus makes movements in three spatial directions.
One of these directions corresponds to the pronator and supinator movements.
When the calcaneus leans over the inner side, we talk about pronation, while if it leans over the outer side, we talk about supination (Fucci, Benigni and Formasari, 2003; Kapandji, 2004).
Normally, the angle formed by the Achilles tendon line and the vertical midline of the calcaneus (also called heel bone) is taken as a reference, to determine supination or pronation.
- When both lines go in the same direction, the degree formed is zero degrees, and its considered a neutral position
- Otherwise, if the lines are not parallel, depending on which way the calcaneus is inclined with respect to the talus, we talk about pronator or supinator.
It’s important to emphasise the importance of the alignment of the ankle-subastragalis joints with the knee and hip in order to maintain a correct position and performance of each of the structures of the lower limb.
Some authors establish “pronation” as a natural mechanism to adapt the foot to the ground, and “supination” as a mechanism to stabilise the forefoot against the hind-foot. Thus, in this case, the foot would act as a strong and rigid mechanism in the propulsion phases, protecting the ankle from instability.
The problems, in terms of injuries and posture, derive from an excess of one or the other.
And while there is not much consensus about the degrees from which it should be considered a problem, we could speak about a difference of almost twice as much in supination as in pronation.
In the case of running, it is considered that in normal operation of the subastragaline joint during the run, the pronation values can reach up to 10º/15º and those of supination up to 20º. (Aguado, 1997).
Therefore, how the load is around the sole of the foot will also affect how it is distributed in relation to the other structures of the lower limbs, pelvic girdle, etc..
What’s the difference?
- A foot is said to be pronated, or the footstep is said to be pronator, when the greatest load is on the inside or there is a high angle between the talus and the ankle joint.
- A foot is said to be supine, or the footstep is said to be a supinator if, on the other hand, the weight falls on the sides of the foot leaving a gap between the plantar fascia and the ground.
In either case, there will be an alteration in the support, and therefore also in the ankle joint and other lower limb structures, even affecting correct posture.
On top of this, and taking into account the natural functionality and biomechanics of the human being, pronation is a necessary movement with which the foot tries to dissipate the impact that occurs when we walk and run, but we are talking about a physiological pronation of around 6 to 8 degrees.
At the level of scientific literature, there is no scientific consensus that establishes a direct relationship between Pronation and Supination (type of foot, cavus, flat or normal), and lower limb injuries.
Several authors do report a higher rate of injury in athletes with pes cavus, with fairly high internal arches.
The following needs to be analysed for this:
- Structure of the foot in the different patterns of movement and the distribution of the loads and impact forces, to determine a greater or lesser incidence of injury in the lower limbs.
- Points of greatest support in natural standing position and if there is good stacking-alienation of the lower limb joints (subastragalis, ankle, knee and hip joints).
This will give us enough information about which other structures of the lower limb are suffering greater loads and/or stresses, and therefore at greater risk of injury.
How do I know if I’m a pronator or a supinator?
Wear and tear of your shoes
It’s very interesting to look at the sole of our shoes and regular footwear: check if there is any area of the sole that suffers more wear than others:
- Normally, if there is heavy wear on the outer heel face of the shoe, this could be an indicator of excessive pronation.
- If, on the other hand, you observe alterations or deformations of the shoe material in the front part, inside the shoe, and even in the outside front of the shoe, it could be an indicator of excessive supination.
Specialists and footstep study
As always, when in doubt, or if you really want to know the health of your feet, the best thing to do is to go to a specialised centre for Sports Podiatry and Biomechanics.
There you can be analysed precisely, both when standing (plantar footstep) and when moving: type of foot, type of footstep when running and walking, as well as postural alignment and hygiene derived from good/bad plantar support.
Many sports footwear brands and shops carry out “footstep studies”, but they lack the knowledge and equipment necessary for this study to be truly reliable.
Do all athlete have to be pronator or supinator?
As mentioned above, pronation is a natural gesture of the foot to absorb certain impact forces and adapt to the terrain, while supination is a protection mechanism against instability of the foot in propulsion.
The foot can take different forms:
- Valgus foot: tendency to walk with the feet inwards, pronation.
- Varus foot: this time the support is made towards the external side, supination.
- Flat foot: little arch, pronation.
- Cavus foot: high arched foot.
How do I choose my shoe if I am a pronator or supinator
When choosing the right footwear, it is necessary that it meets 3 basic characteristics:
- That it protects the foot from possible external damage;
- That it’s functional footwear, that’s to say, that it allows the foot good mobility and doesn’t deform its structure;
- That it minimises the proprioceptive sense of the foot.
A trainer with pronation or supination control does not correct the existing misalignment at the motor control level, but rather perpetuates it, because the foot is not forced to correct the movement.
There are many foot and ankle strength, joint mobility and proprioceptive work exercises to improve the functionality of the musculoskeletal structures.
To summarise the above, and in line with my experience with runners, except for excessive degrees of pronation/supination determined by the biomechanical specialist, where the temporary use of insoles is necessary, I particularly advocate comprehensive strength and mobility work for the feet, lower limbs and improved joint alignment.
- Brigaud, F. (2016) “ La Carrera. Postura, Biomecánica y Rendimiento”, Paidotribo.
- Rojano Ortega, D. Y colaboradores (2009), “Análisis de la pronación y supinación subastragalinas en la marcha atlética”, 51-58, Educación Física y Deportes, ISSN-1577-4015.
- Subotnick, S. I. (1985). The biomechanics of running. Implications for the prevention of foot injuries. Sports Medicine (2), 144-153.
- Get advice on picking running trainers at this link.
- If you’re going to start running from scratch, we recommend you read this article.