One of the most common injuries in sports like distance running is arch pain in the foot.
And while you may assume that it’s plantarfasciitis, there are a long list of other possibilities and causes.
Anatomy of the arch of the foot
The arch of the foot is wonderfully simple in its function and complex in its design.
It’s basically a collection of block-like bones (called the tarsal bones) that make up the midfoot along with some longer bones (metatarsals) that extend down towards the toes.
These bones and their joints allow the foot to change shape and adapt to a range of surfaces, angles and positions.
Then there’s a series of connective tissue bands, ligaments and fascia, that join it all together – and that’s where the magic happens.
They allow the foot to move into a huge range of positions but then they brace it tight, providing a rigid platform for the leg to operate on.
The main player in the function of the arch is the plantarfascia, connecting from the heel to the toes.
It stores energy like a big spring but also braces the foot when the toes are bent back, like when you’re about to push off for a sprint start.
But just like any complex bit of machinery, if any part of the system is out of balance or overloaded, it causes trouble.
In the case of the foot, it causes arch pain…
Types of injuries that can cause arch pain
Arch pain in the foot can be divided into two categories – sudden (or acute onset) and gradual (or insidious) onset.
Acute injuries are typically associated with an incident. For example, your foot lands awkwardly or you misjudged a step.
The reason for an insidious (gradual) onset injury is harder to pick.
The arch pain gradually comes on and gets worse, although it’s hard to pick the exact moment that you first noticed it.
It might be linked to that one big run? The new shoes? Or a pair that’s overdue for replacement? Maybe it’s a bit of everything?
We’ll cover the most likely cause of your arch pain and how it could have started.
We’ll also go step-by-step on how you can diagnose your injury.
Acute or sudden onset injuries
If the arch pain in the foot occurs suddenly, you can probably figure out what caused the overload.
Stepping on a stick or rock that bends the front of the foot.
Landing heavily from a jump.
Having your toes bent back sharply as you stumble.
As this happens, there are a number of structures that take the brunt of the force.
If your toes bend back, the plantarfascia and toe muscles stretch rapidly.
This can cause the connective tissues (like the plantarfascia) or muscle fibres deep in the arch to tear.
Even if it doesn’t cause damage, it can cause a reactive inflammatory response in these structures.
If your foot bends or twists in the middle, it can cause joints and ligaments in the midfoot to compress or stretch.
This can strain ligaments, such as the Spring ligament (deep in the arch, under the Plantarfascia), or cause joint impingement (pinching).
How to diagnose & treat your arch pain in an acute injury
Diagnosis is quite important.
If it’s a reactive tendinopathy or joint impingement, it responds really well to anti inflammatory medication.
But if it’s a ligament or plantarfascia tear, that medication will cause further bleeding and disrupt the healing process.
Here are some basic rules to follow:
- If you see bruising, don’t use anti-inflammatories. It means that one or more structures are damaged rather than just reacting or inflamed.
- If it’s obviously swollen, get some compression on to it ASAP. That’ll reduce how much more swelling accumulates in the area. Make it firm but not restrictive.
- If it’s worse after rest or sleeping but improves with activity, your arch pain has an inflammatory component. That doesn’t always mean that medication is helpful but it does indicate that prolonged rest is a bad call.
- If it aches constantly and is very painful to stand on, consider getting an x-ray to check for fracture.
- If it hurts to stretch the painful area, but not to compress it, it’s probably a ligament or connective tissue like the plantarfascia (For example, pointing your toes away hurts on top of your foot but pulling your toes towards your shin is fine.) It responds well to support, such as taping, and gradual reloading.
- If it hurts to compress the area but isn’t painful on stretching, it’s probably joint and should respond well to gentle activity and anti inflammatory medication.
Gradual onset injuries
Most episodes of foot and arch pain begin gradually, with symptoms becoming more noticeable over time.
This presents two issues. Firstly, it’s difficult to figure out exactly when it started.
Secondly, it’s hard to figure out the likely cause as there wasn’t a single incident or event that triggered it.
Finding the cause is vital. How can you fix an overload injury when the overload is still happening?
As a hint to find the cause, one-sided injuries almost always have one-sided causes.
If the arch pain is just in your left foot, it won’t be due to old shoes or too much training.
Those causes may contribute to an overload but they won’t create a one-sided injury on their own.
Otherwise your injury would affect both feet (assuming you took both feet on every run…)
How to diagnose & treat a gradual onset arch pain
For gradual onset injuries, it’s important to know the difference between what makes it feel better and what actually fixes it.
Taking anti-inflammatories might take the pain away for hours, but is it helping? Or just masking the arch pain while the injury gets worse?
Here are some guidelines:
- If it loosens up with activity and stiffens up when you cool down, it has an inflammatory component. Try ice after exercise to manage the reaction.
- Nasty arch pain on waking which eases over the next 10-15 minutes, is a classic sign of plantarfasciitis. Wear supportive shoes and add strength exercises, particularly targeting your stabilisers.
- Constant pain that’s sore on walking could be a stress fracture. Get it checked out by a health professional and scanned – MRI or bone scan works best as X-ray can miss subtle changes.
- Pain and swelling that’s localised to your big toe joint. It’s most likely a hallux valgus but it could be gout. If it flared up without obvious overload and it’s very red and swollen, consider getting screened for gout.
- Pain that’s just on the top of the foot and is sore to touch might be a joint impingement. If it loosens up with walking, try supportive shoes, ice after exercise and topical anti-inflammatory gel such as Voltaren Emulgel.
Take home message
If you’re feeling arch pain, you need to figure out what caused it.
Don’t just assume that arch pain = Plantarfasciitis, although it is a common cause of arch pain.
If in doubt, see your trusty local health professional – you don’t want to miss injuries like stress fractures and they can also help to identify what caused the injury, to prevent future episodes of the same thing.