Feet- 'Flat' but still functional? Hyperpronation, orthotics, gait and glutes...
Updated: Feb 6, 2021
Often in clinic I have patients who come in telling me they have been told they have 'flat feet' or pronate too much. For some, this can be an issue which causes imbalances up the chain in the knees, hips, pelvis and lower back (and even then up from there!) but for others, when we look in more detail, their 'flat feet' don't actually seem to be much of an issue at all!
So, how do we assess the feet and their relevance to the rest of the body?
Firstly, let's look at the anatomy...
There are 26 bones in each foot, and 3 main arches: The Medial (inside) longitudinal arch, the Lateral (outside) longitudinal arch and the Transverse arch.
The arches are all supported by a number of muscles, mainly being: Tibialis posterior, Tibialis anterior, Peroneus Longus and Tertius, Flexor Hallucis Longus and Flexor Digitorum Longus, as well as the plantar fascia/aponeurosis and many ligaments.
The foot is split into 3 main anatomical and functional zones:
The hindfoot includes talus and calcaneus.
The midfoot includes navicular, cuboid, and cuneiforms.
The forefoot includes metatarsals and phalanges.
As I've mentioned in other blog posts, static observation is only one small part of the overall picture and, especially when it comes to feet, function is key. The best ways to assess people's feet and the impact they're having on the rest of the body is to watch them move!
1) Gait analysis- either walking in the treatment room or walking on a treadmill (even better to watch you walk or run outdoors!). Sometimes we may video this and play it back in slow motion.
The gait (walking) cycle has two main phases:
Stance phase- consisting of components such as heel strike, mid stance and toe off.
During these phases our feet should control the arches in:
Supination- high arch position, rigid foot, mainly seen at initial heel strike and the propulsive phase of gait (heel/toe off).
Pronation- low arch position, flexible foot, mainly seen in the stance phase of gait to shock absorb (mid-stance).
At each stage we can watch what your foot is doing (and what your knee/hip/pelvis/shoulder/neck etc are doing to potentially compensate!). Are you pronating too soon or in an uncontrolled way? Is your knee bowing in? Is your pelvis dropping? Do you lack sufficient toe off/propulsion? Is your trunk rotation effectively? There's a lot to potentially pick up on!
2) Shoe wear patterns
Patients are often a bit reluctant to hand over their old smelly trainers to me... and a bit confused when they see the look of excitement on my face! But shoe wear can tell us a lot.
Ideally we should heel strike slightly more towards the outer aspect of the heel and put fairly well distributed pressure through the ball of the foot, with slightly more push off coming from the big toe.
Things to look out for include: Excess heel wear (heavy heel strike? Long stride length?), excess forefoot wear (heavy forefoot strike? Increased pressure on the metatarsal heads with transverse arch collapse?), excess outer shoe wear ('bracing strategy' overusing the muscles up the chain? Lack of sufficient toe off from the big toe?), excess first toe wear ('releaser strategy' with uncontrolled pronation?), uneven left vs right shoe wear (asymmetry up the chain into or from the knees/hips/pelvis? Leg length asymmetry?).
3) Structural observations
For things like bunions (hallux valgus), morton's toe structure (first metatarsal shorter than the second), calluses (indicating excess pressure in certain areas of the foot), forefoot widening or hindfoot/calcaneus position. Flat feet on static observation are actually described as Pes Planus, and overly arched feet are described as Pes Cavus. In movement this equates to Hyperpronation and Supination.
4) Gait movement control patterns- broken down
We can then break the gait cycle down and test the movements of each individual stage, for example:
Supination control- standing on one foot and turning the trunk to the outer/same side. Does the big toe joint (1st MTP joint) lift up off the floor and the toe curl, indicating overactivation of the long toe flexor as a bracing strategy?
Pronation control- standing on one foot and reaching the other foot forward and out to the other side, letting the stance leg knee bend.
Lunge control- to gauge hip extension, frontal plane control of the pelvis and knee etc.
Squat control- to gauge ankle dorsiflexion, frontal plane control of the pelvis and knee etc.
Single leg balance
Other tests we often use are the Navicular drop test (measuring how much the inner midfoot drops down weight bearing after putting the hindfoot in a neutral position) or test for First Metatarsal drop (measuring how much the big toe drops down weight bearing after putting the hindfoot in a neutral position).
6) Manual muscle testing
As discussed in my other blog post 'How resilient are you? Muscle activation, strength and the nervous system...', we can then get even more specific and test each movement within the gait cycle with specific muscle tests, for example:
Hip abduction- to gauge glute muscle control/frontal plane stability during single leg stance
Hip extension- to gauge the muscles of propulsion during push off
Lower leg internal rotation- to gauge the strength of the popliteus muscle, which helps unlock the knee
Trunk rotation including the anterior (front) and posterior (back) oblique muscle slings of the body- to gauge core control, coordinating the the arms and the legs together
Gluteal (buttock) muscle control is particularly key within the gait cycle.
7) Joint and muscle palpation
To determine specific restrictions within the body that may be adding to these other patterns, for example: decreased ankle dorsiflexion due to talus restriction (often seen after ankle sprains), decreased hip extension due to tight hip flexors or sacroiliac joint restriction, decreased trunk rotation due to thoracic spine restriction etc!
Using all of these tests we can work out what may be causing issues or compensation in each individual. Then it's sometimes a chicken and egg situation of working out what came first- the foot issue or the issue higher up the chain!
In some cases, orthotics may be suggested and adapted suited to each individual. The main thing to remember when using orthotics is that, we still ideally want to use home exercises and treatment to strengthen your foot muscles at the same time so you are not over reliant on them. Some people just need orthotics in the short term, others with more enhanced structural issues may need them in the longer term. Either way, it's about reassessing them and how your body is adapting to them along the way to to ensure they are still the right option for you.
Feet can tell us a lot and cause a lot of issues, but we've got to ensure that your 'flat feet' are definitely relevant to your complaints before shoving your foot in an orthotic or super expensive running shoe! Some people have flexible 'flat feet' (or indeed high arches) without any functional mobility/stability issues locally or up the chain.
Detailed gait analysis, observation, functional movement control, muscle testing and palpation allows for a more appropriate management plan.
Function is key...
Functional feet = Functional knees/hips/pelvis and up!
The E3 Rehab Podcast 'The Pronation Problem...' with Ian Griffiths, a podiatrist