Last updated:21st March 2016

AS and feet

The average person walks about 70,000 miles in a lifetime - 4 times around the world

Most of the time we take for granted that this will happen without any trouble and that our feet will do exactly what we want, when we want them to. But this isn't always the case - throw into the mix a slight amount of pain in the foot or elsewhere in the body and things start to change.

Your body is very good at changing the way you move if a certain area becomes painful. A small but uncomfortable corn under your right foot becomes painful after a mile of walking. This leads you to spend more time on your left leg, resulting in pain in either your left knee or back. This is because your gait (walking) pattern has changed, and you are using muscles and joints in different ways.

So how does all this fit in with AS?


The foot is made up of 26 bones, many ligaments (soft tissue which joins bone to bone), tendons (soft tissue which joins muscle to bone), blood vessels, nerves and other soft tissues.

Feet are technically brilliant structures of engineering, adopting many positions.

Each movement has an impact on your leg and consequently your hips and back. If the ‘timing', loading or strength of your foot or lower limb is altered then your body will compensate for this - sometimes very effectively without any pain but sometimes causing great discomfort.

Foot problems

Just because you have AS doesn't mean you will develop foot problems - but there are a few foot problems that seem to be more common with AS.

Plantar fasciitis

Also known as ‘policeman's heel' and is inflammation at the site where the plantar fascia (a soft tissue structure under the foot) attaches to the heel bone.
The most common symptoms are:

  • Pain under the heel - often towards the inside of the heel and/or the arch
  • Worse first thing in the morning and during your first steps after sitting
  • May be worse after long periods of standing or walking
  • Pain can vary from mild discomfort to excruciating pain

There is a lot that can to help. A physiotherapist or podiatrist is the best source of help.

One of the most important things to do is calf stretches as tight calves often cause or worsen this condition

Other treatments include:

  • Plantar fascia stretching
  • Taping of the foot
  • Night splints
  • Cortisone (steroid) injection
  • Insoles or orthotics (bespoke insoles)
  • Change of footwear - trainers are often a great choice.
  • Being overweight can cause or worsen the condition so weight loss can help

Insertional achilles tendinitis

This is inflammation where the Achilles tendon attaches to the back of the heel bone.

The most common symptoms are:

  • Pain at the back of the heel
  • Back of the heel is red and swollen
  • Painful when doing weight-bearing activity - such as walking
  • Bony bump may develop at the back of the heel called a Haglund's bump, as well as a bursa (fluid filled sac)

Tight calf muscles can worsen the condition so gentle calf stretches need to be carried out

If the pain is very severe then a heel raise may be necessary at first to offload the tendon on the heel bone.

Insoles/orthotics may be used to alter any foot function anomalies and sometimes more specific exercise plans can help.

If the bursa is the main problem then a cortisone injection can sometimes be useful.

Supportive footwear which doesn't irritate the back of the heel is essential.

Cramping and toe clawing

Cramps and clawing of the toes can occur in people with AS.

If your posture has changed due to pain and/or fusion in the spine then the loading through your legs and feet will change. Muscles which are now being used more or just differently can be more prone to spasms.

If you have a forward curve of your spine then you may notice your toes clawing in an attempt to gain stability from falling over. If your spine is fused in this way (particularly upper spine) then often your knees will be in a flexed position helping you to stand more upright. This can cause shortening of one of the calf muscles and sometimes knee pain.

Your GP can help with medication for cramps. It is also worth asking for a referral to a podiatrist or physiotherapist to check for any muscle imbalance and foot function problems which may be helped by exercise plans and insoles/orthotics.


Ideally you need to be wearing footwear with good shock absorbency to reduce jarring through the joints, particularly the spine. Trainers are obviously great for this but they aren't always practical.
Insoles such as Sorbothane are excellent at shock absorbing and can be put into most good footwear.

They can be bought from good sports shops, especially those that specialise in running, as they are often used for shin splints.


Podiatrists can help with all of these conditions and give lots of advice.

A podiatrist is a health professional who treats people with problems of the feet, ankles, lower limbs and beyond.

Podiatrists are trained to do vascular and neurological assessments, nail surgery, biomechanical assessments, provide orthotics, insoles and exercise plans and wound care.

How to be referred to a podiatrist varies nationally - some NHS podiatry departments have a self-referral system whereas others only accept referrals from other health care professionals such as your GP or physiotherapist. It is worth calling your local podiatry department or GP surgery to find out. If you decide to go privately, do ensure that your podiatrist is HPC (Health Professions Council) registered. You can find a list of private podiatrists and more advice at www.feetforlife.org.

Overall advice

Feet tend to be overlooked and forgotten about until things go wrong.

If you notice any persistent pain, unusual symptoms or changes in the shape of your feet then try to see a podiatrist for their opinion. They will assess, advise and treat you accordingly and sometimes refer you on for further investigations.

Having foot pain really is no fun!

Louise Skipp
Biomechanics Specialist Podiatrist
Royal National Hospital for Rheumatic Diseases




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