Memory Foam Trainers – ARE YOU RUNNING ON AIR OR WALKING TOWARDS DISASTER?

Memory foam soles

Memory foam mattresses have been with us for some considerable time and can enable and support a good nights sleep while maintaining postural alignment. So why not use Memory foam to support your feet in comfort while you are up and about? A particular heavily marketed American brand, that states it is a “lifestyle and performance footwear company” is well known amongst Podiatrists as contributing to multiple foot, knee, hip and back problems. Why?

Points to consider

How thick is the foam on your mattress? This is supporting your entire body weight but over a large surface area.
How thick is the foam on your trainers? Certainly not the depth of a bed mattress (the Monty Python “Ministry of Silly Walks” comes to mind if they were). Therefore your entire body weight is bearing down through your feet onto a thin segment of low density polyurethane within each trainer. However as soon as you start to move, the impact effects of your body weight on your foot strike changes significantly. Walking produces 1.5 of body weight impact, whereas runners impact the ground with 3 times their body weight with every step.
If you are overweight, have developed joint problems or have an over pronated or supinated foot placement the effects of body weight impact are critical in avoiding injury.

What is pronation?

Pronation is often referred to as a “neutral” motion of your foot during running and walking. In short, all of your toes push off with the big toe and second toe doing most of the work and the sole of the foot facing the rear of your body, without tilting either in or outward. As the foot rolls upward and forwards, the arch stiffens to stabilise the movement. Your weight then shifts slightly to the outside of the foot before returning to the big toe to complete the action.

What is over pronation?

In over pronation, the ankle rolls too far downwards and drops inwards with each stride. It continues to drop and roll when the toes begin to push off. As a result the big toe and second toe do all the pushing off and as a consequence, the foot twists more with every step.
This foot strike is most often associated with those who have a dropped arch (flat feet) although not everyone with flat feet over pronate. Long term, this problem can lead to strain on the posterior tibialis tendon, knee pain or shin splints (Medial Tibial Stress Syndrome).
Motion control shoes/trainers, insoles and orthotics are all designed to correct your foot motion should you over pronate.

What is supination?

Occasionally referred to as “Underpronation” , the foot rolls to the outside edge during each step. The foot does not pronate sufficiently in the toe off phase resulting in the outer edge of the foot and smaller three toes doing all the work thus placing additional stress on the foot. Supination can frequently be seen in those with high, ridged arches that do not flatten sufficiently during each stride. It can also be associated with several running injuries including Achilles Tendonitis, Iliotibial Band Syndrome and Plantar Fasciitis, the latter being the subject of my next blog.
Supportive training shoes that are well cushioned and flexible are essential for those who supinate. However, whether for running or for fitness walking foam trainers are definitely not a sensible option!

Self diagnosis of your gait

As non-essential retail shops are currently unable to trade and until they are able to, the following guide will give you an indication as to how your feet are functioning –

* Shoe tilt: locate a pair of shoes or boots that you have been wearing regularly for sometime, at least a couple of months. Place them on a table with the heels facing you. If the shoes tilt inwards due to an increased wear pattern on the inner side of the heel, you may be an OVER PRONATOR. If the heels tilt outwards, you maybe a SUPINATOR.

* Shoe wear pattern: next look at the soles on your current running or fitness walking trainers.. OVER PRONATORS will see more wear on the inner side of the heel, with SUPINATORS seeing the pattern of additional wear on the outer edge.

For a professional gait analysis, an athletic shoe expect can watch you run or walk, or via video gait analysis. Many sales people in specialty running shops are trained to spot your gait pattern and suggest the correct shoes accordingly. If you have a mild discomfort or a slight deviation from the “normal” pronation pattern, these specific shoes may be sufficient to improve your comfort and performance. In case of continuing pain or severe discomfort, the services of a Podiatrist may be required who will be able to provide you with prescription insoles.

If you want help analysing your gait, or believe you have ankle, knee or hip pain, caused by your gait movement, please speak to our Postural Improvement expert, Personal Trainer Daniel James.

How your gait affects memory foam trainers?

If you have great biomechanics ie “ neutral” motions with no issues then you should be ok with memory foam soles, but they will need to be changed on a more regular basis than traditional training shoes. Simply put, low density polyurethane compresses relatively quickly and the foam effectively develops “Insole Alzheimer’s” whereby it is unsure how to react and what is should be doing! That not good or beneficial for the wearer as muscle stresses and strains are more likely and ligament damage a possibility.
If you over pronate or supinate, the memory foam takes on the “memory” of your gait disorder, thereby exacerbating the issue as the foam continues to break down in specific areas of the shoe. Long term this destabilises the foot and can lead to ankle, knee, hip and back pain.

So are memory foam trainers a no no?

For fitness, biomechanical data and assessments from a wide variety Podiatrists should be noted. For casual / lifestyle wear, as long as you are aware that the structure will not last very long………

Article written by Personal Trainer and Sports Therapist Wendy James. Please click here if would like to ask any questions.