The plantar fascia is the thick connective tissue which supports the arch on the bottom of the foot. It runs from the tuberosity of the calcaneus (heel bone) forward to the heads of the metatarsal bones (the bone between each toe and the bones of the mid foot).In younger people the plantar fascia is also related to the Achilles tendon, with a continuous fascial connection between the two from the distal aspect of the Achilles to the origin of the plantar fascia at the calcaneal tubercle. However, the continuity of this connection decreases with age to a point that in the elderly there are few, if any, connecting fibres.
Plantar fasciitis is when this thick connective tissue becomes inflamed. It is often caused by overuse of the plantar fascia, increases in activities, weight or age. Longstanding cases of plantar fasciitis often demonstrate more degenerative changes than inflammatory changes, in which case they are termed plantar fasciosis. The suffix "osis" implies pathology of chronic degeneration without inflammation. Since tendons and ligaments do not contain blood vessels, they do not actually become inflamed. Instead, injury to the tendon is usually the result of an accumulation over time of microscopic tears at the cellular level. ‘What is tendinopathy’ blog can help explain this concept in further detail.
Planter fasciitis Risk factors
Age. Plantar fasciitis is most common between the ages of 40 and 60.
Sex. Women are more likely than are men to develop plantar fasciitis.
Certain types of exercise. Activities that place a lot of stress on your heel and attached tissue such as long-distance running, ballet dancing and dance aerobics can contribute to an earlier onset of plantar fasciitis.
Faulty foot mechanics. Being ‘flat-footed’or even having an abnormal pattern of walking can adversely affect the way weight is distributed when you're standing and put added stress on the plantar fascia.
Poor running technique. This will be discussed in more detail later on
Obesity. Excess pounds put extra stress on your plantar fascia.
Occupations that keep you on your feet. Factory workers, teachers and others who spend most of their work hours walking or standing on hard surfaces can damage their plantar fascia.
Improper shoes. Avoid loose, thin-soled shoes, as well as shoes without enough arch support or flexible padding to absorb shock. Also if you regularly wear high heels it is shown that your Achilles tendon can shorten, causing strain on the tissue around your heel.
Wearing appropriate footwear is perhaps the single most effective way of managing the condition as it will help reduce stress on the planter fascia. Plantar Fasciitis is primarily considered a condition where the fascia is subject to excess load and responds with physiological changes and pain. Therefore the purpose of the footwear should be to reduce load on the plantar fascia through footwear selection. There are 3 premises to this approach; and
Increased load on the calf complex and Achilles tendon has been associated with increase load on the plantar fascia. In terms of footwear a shoe with a reasonable heel section and heel to toe drop would be deemed more appropriate. The use of a heel raise would also decrease load on the Achilles. The most effective heel raises would be one that provides extra cushioning as this will also allow shock absorption capabilities during contact of the heel to the ground further reducing stress on the plantar fascia.
supporting the arch using orthotics can be effective in managing plantar fasciitis. It would seem then that a shoe that incorporates arch support help. Custom orthotics will place the foot in a more neutral position so less stress would be placed on the planter fascia when there is contact with the ground. It will also reduce excessive pronation which has also been shown to add increased strain on the fascia and therefore custom orthotics have been shown to be effective in short and long term treatment of pain. The ‘Importance of biomechanics’ blog can explain this concept in further detail.
The windlass mechanism describes how dorsiflexing the big toe increases stress on the plantar fascia;
Therefore a shoe with a fairly firm inflexible toe section rather than one that allows a lot of movement would be deemed more appropriate.
Take home points on shoe selection
Good heel section with at least 10mm hell toe drop will decrease load on the Achilles and Planter fascia
Mid-section with a firm but well cushioned arch support
A fairly firm toe selection that resists excess bend will reduce effects of the Windlass mechanism
It is impossible to recommend a show that will suit everyone. Comfort is key ! A shoe that incorporates the above characteristics is usually far more comfortable for someone with planter fasciitis than an unstructured flat shoe like this
So as a rule of thumb avoid shoes such as pumps and other dolly shoes and in particular high heels. Your Shoe selection should not just be specific to running either but consider the right shoe for you with work and leisure, as prolonged standing and walking at work have been associated with plantar fasciitis so choose the right footwear for this too!
Even with the ‘best shoes’ a keen runner with a poor technique is going to be very susceptible to acquiring planter fasciitis and to put it simplistically runners who have a lot of emphasis on ‘heel strike’ are the most likely to suffer. This is because at heel strike we place 3-5 times our own body weight in force at the heel. This force not only puts excessive load on the fascia but an excessive heel strike is also more likely to cause over pronation at mid stance and this added rotational force is going to add further stress. Runners who take longer striders are going to heel strike more due to the positing of the foot
So what about forefoot running?
Well forefoot running would definitely reduce the force going through the heel however it will increase load on the calf complex and it will increase the great toe dorsiflexion (windlass mechanism) and as such cause stress on the planter fascia. So its all about Balance !
Runners should adopt a running technique where they are not putting emphasis on the heel strike and similarly not adopting an excessive fore foot strike approach.
A more ‘midfoot strike’ approach is going to reduce force going through the heel and the effects of the windlass mechanism.