Posterior ankle impingement – Symptoms, tests, and treatment
Posterior ankle impingement – Symptoms, tests, and treatment
Posterior ankle impingement – Symptoms, tests, and treatment
Posterior ankle impingement causes pain in the back of the heel and is often misdiagnosed as Achilles Tendonitis. In this article, we’ll look at what it is, how to diagnose it, and how to treat posterior ankle impingement without surgery. Remember, if you need help with an Achilles injury.
In this article:
What is posterior ankle impingement?
In short, it’s when something (bone or soft tissue) is pinched in the back of the ankle joint when you move. Let’s look at why this may happen.
The lower ends of the tibia (shin bone) and fibula form the ceiling of the ankle joint and the talus bone the floor. The talus sits on the calcaneus (heel bone).
When you perform plantar flexion – so, pointing your toes down or going up on your tiptoes – the bones that form the ankle joint move closer together at the back. Now, this is a normal movement, so why will this cause pain?
When you point your foot down, the bones at the back of the ankle move closer to each other.
Causes of posterior ankle impingement
There are two main causes of posterior ankle impingement:
Overtraining in a sport or activity that repetitively force the ankle into strong plantar flexion.
Injuring your ankle and not allowing it to fully recover before resuming sport or activity.
The pain in the back of the ankle can be caused by the bones being compressed, soft tissue being compressed, or sometimes both.
Sports and activities that predisposes people to developing posterior ankle impingement include football, basketball, and ballet.
Cricket fast bowlers are the exception to the rule; they are prone to getting posterior ankle impingement through forced dorsiflexion (slamming the foot down as they bowl), causing the bones to slide and impinge in the back due to the force of the movement.
Bony abnormalities are only a part of the problem
When people complain of posterior ankle pain, and they scan their ankles, they often find abnormalities in the bones.
People may have an extra, loose little bone (called an os trigonum), bony spurs (osteophytes causes by arthritis), or a long, pointy talus (Stieda’s process). These have been blamed in the past for causing posterior ankle impingement.
Bony abnormalities that may predispose you to getting posterior ankle impingement include: (A) os trignonum, (B) bony spurs, (C) Stieda’s process.
However, these bony abnormalities are also found in people who have no ankle pain and are just as active. Also, the majority of people can recover from posterior impingement despite the extra bone still being there. So, why do they cause pain for some people and not others?
The current thinking is that, rather than causing the impingement, these bony structures may just make you more prone to it. It seems that you only develop symptoms if you do repetitive movement that strongly compress the back of the ankle or experience a traumatic event, e.g. your foot is forced into extreme plantar flexion while playing football.
Overuse causes
Sometimes the soft tissue that surrounds the ankle joint (e.g. the joint capsule or a tendon) gets pinched. Common reasons for this include:
Ongoing ankle instability, causing the joint to move too much; this often happens when someone has sprained their ankle and they have not properly strengthened it back up.
Thickening of the soft tissue due to ongoing irritation of either the capsule or tendons (especially the flexor hallucis longus and peroneal tendons); this is often caused through overuse (e.g. ballet dancers practising lots of en pointe) or if you don’t treat a sprained ankle properly.
Some people may have extra muscles in the area that get pinched; these are, however, also present in people without causing problems, so it is unclear whether these extra muscles are truly part of the cause.
A trauma event
If your ankle joint is forced into strong plantar flexion (like when you sprain it or just move it forcefully into that position) it can also injure the joint surface, causing injuries to the cartilage, bone, and soft tissue.
Similar to other injuries, this causes inflammation and swelling in the back of the ankle (as part of the healing process), resulting in impingement symptoms.
This type of impingement is the easiest to treat, because it just requires you to look after your ankle and allow it to calm down and heal. As soon as it has healed, the swelling goes down and the symptoms disappear.
How to diagnose posterior ankle impingement
Step One is to listen to the patient and check whether the symptoms they report fit the typical picture of posterior impingement.
The typical symptoms people report when they have posterior ankle impingement include:
Pain in the back of the ankle or heel; it usually feels deep, and it is often difficult to precisely pinpoint where it is coming from.
The pain can be described as sharp, dull, or radiating.
The pain is usually felt during or made worse by activities that require them to go up on their toes, forcefully push off, or where their foot has to move into strong plantar flexion, e.g. ballet, kicking in football, walking or running down hills, or wearing high-heeled shoes.
Where you feel the pain when you have posterior ankle impingement.
This is followed by a physical examination; we guide our patients through these tests via video call:
When you press in the area, it typically feels tender at the back of the ankle, above the heel bone, and behind the Achilles tendon. The tender area may be located more to the outer or inner back of the ankle.
When you move the ankle into passive plantar flexion (i.e. using your hands to move it so that the muscles and tendons remain relaxed), it usually reproduces the symptoms.
If passive movement of the big toe (bending it back) causes pain, the flexor hallucis longus tendon may also be injured.
Scans can be useful to confirm the diagnosis or to rule out more serious issues, but most cases can be diagnosed without them. The typical scans used include:
X-rays: They can show bony abnormalities, but they don’t show soft tissue or joint injuries. Also, just because you have a bony abnormality does not mean you have posterior ankle impingement, since 25% of uninjured people have them as well.
MRI scans: These are best for showing soft tissue injuries, fractures, bone marrow edema, cartilage injuries, etc.
CT scans: They are best for showing bony injuries that are sometimes difficult to see on X-rays.
Your physiotherapist will listen to how your injury started and how your symptoms are reacting and combine that with the results of the physical examination to decide whether a scan is needed and what type would likely be the most useful.
Things that can be mistaken for posterior ankle impingement
There are other conditions that can cause very similar pain to posterior ankle impingement. It is therefore important that your physio or doctor test for these as well:
Achilles tendon injuries, e.g. Achilles tendonitis or tears
Peroneal Injuries
Tibialis Posterior Injuries
Flexor halluces longus injuries
Ankle osteoarthritis
Tarsal Tunnel Syndrome
Injuries to the tibial and sural nerves
Referred pain from the lower back – L5, S1, or S2 nerve root irritation.
It is, of course, possible to have posterior ankle impingement in combination with any of these injuries as well.
Call Now
Posterior ankle impingement – Symptoms, tests, and treatment
Posterior ankle impingement – Symptoms, tests, and treatment
In this article:
In short, it’s when something (bone or soft tissue) is pinched in the back of the ankle joint when you move. Let’s look at why this may happen.
The lower ends of the tibia (shin bone) and fibula form the ceiling of the ankle joint and the talus bone the floor. The talus sits on the calcaneus (heel bone).
When you perform plantar flexion – so, pointing your toes down or going up on your tiptoes – the bones that form the ankle joint move closer together at the back. Now, this is a normal movement, so why will this cause pain?
Causes of posterior ankle impingement
There are two main causes of posterior ankle impingement:
Overtraining in a sport or activity that repetitively force the ankle into strong plantar flexion.
Injuring your ankle and not allowing it to fully recover before resuming sport or activity.
The pain in the back of the ankle can be caused by the bones being compressed, soft tissue being compressed, or sometimes both.
Sports and activities that predisposes people to developing posterior ankle impingement include football, basketball, and ballet.
Cricket fast bowlers are the exception to the rule; they are prone to getting posterior ankle impingement through forced dorsiflexion (slamming the foot down as they bowl), causing the bones to slide and impinge in the back due to the force of the movement.
Bony abnormalities are only a part of the problem
When people complain of posterior ankle pain, and they scan their ankles, they often find abnormalities in the bones.
People may have an extra, loose little bone (called an os trigonum), bony spurs (osteophytes causes by arthritis), or a long, pointy talus (Stieda’s process). These have been blamed in the past for causing posterior ankle impingement.
However, these bony abnormalities are also found in people who have no ankle pain and are just as active. Also, the majority of people can recover from posterior impingement despite the extra bone still being there. So, why do they cause pain for some people and not others?
The current thinking is that, rather than causing the impingement, these bony structures may just make you more prone to it. It seems that you only develop symptoms if you do repetitive movement that strongly compress the back of the ankle or experience a traumatic event, e.g. your foot is forced into extreme plantar flexion while playing football.
Overuse causes
Sometimes the soft tissue that surrounds the ankle joint (e.g. the joint capsule or a tendon) gets pinched. Common reasons for this include:
Ongoing ankle instability, causing the joint to move too much; this often happens when someone has sprained their ankle and they have not properly strengthened it back up.
Thickening of the soft tissue due to ongoing irritation of either the capsule or tendons (especially the flexor hallucis longus and peroneal tendons); this is often caused through overuse (e.g. ballet dancers practising lots of en pointe) or if you don’t treat a sprained ankle properly.
Some people may have extra muscles in the area that get pinched; these are, however, also present in people without causing problems, so it is unclear whether these extra muscles are truly part of the cause.
A trauma event
If your ankle joint is forced into strong plantar flexion (like when you sprain it or just move it forcefully into that position) it can also injure the joint surface, causing injuries to the cartilage, bone, and soft tissue.
Similar to other injuries, this causes inflammation and swelling in the back of the ankle (as part of the healing process), resulting in impingement symptoms.
This type of impingement is the easiest to treat, because it just requires you to look after your ankle and allow it to calm down and heal. As soon as it has healed, the swelling goes down and the symptoms disappear.
How to diagnose posterior ankle impingement
Step One is to listen to the patient and check whether the symptoms they report fit the typical picture of posterior impingement.
The typical symptoms people report when they have posterior ankle impingement include:
Pain in the back of the ankle or heel; it usually feels deep, and it is often difficult to precisely pinpoint where it is coming from.
The pain can be described as sharp, dull, or radiating.
The pain is usually felt during or made worse by activities that require them to go up on their toes, forcefully push off, or where their foot has to move into strong plantar flexion, e.g. ballet, kicking in football, walking or running down hills, or wearing high-heeled shoes.
This is followed by a physical examination; we guide our patients through these tests via video call:
When you press in the area, it typically feels tender at the back of the ankle, above the heel bone, and behind the Achilles tendon. The tender area may be located more to the outer or inner back of the ankle.
When you move the ankle into passive plantar flexion (i.e. using your hands to move it so that the muscles and tendons remain relaxed), it usually reproduces the symptoms.
If passive movement of the big toe (bending it back) causes pain, the flexor hallucis longus tendon may also be injured.
Scans can be useful to confirm the diagnosis or to rule out more serious issues, but most cases can be diagnosed without them. The typical scans used include:
X-rays: They can show bony abnormalities, but they don’t show soft tissue or joint injuries. Also, just because you have a bony abnormality does not mean you have posterior ankle impingement, since 25% of uninjured people have them as well.
MRI scans: These are best for showing soft tissue injuries, fractures, bone marrow edema, cartilage injuries, etc.
CT scans: They are best for showing bony injuries that are sometimes difficult to see on X-rays.
Your physiotherapist will listen to how your injury started and how your symptoms are reacting and combine that with the results of the physical examination to decide whether a scan is needed and what type would likely be the most useful.
Things that can be mistaken for posterior ankle impingement
There are other conditions that can cause very similar pain to posterior ankle impingement. It is therefore important that your physio or doctor test for these as well:
Achilles tendon injuries, e.g. Achilles tendonitis or tears
Peroneal Injuries
Tibialis Posterior Injuries
Flexor halluces longus injuries
Ankle osteoarthritis
Tarsal Tunnel Syndrome
Injuries to the tibial and sural nerves
Referred pain from the lower back – L5, S1, or S2 nerve root irritation.
It is, of course, possible to have posterior ankle impingement in combination with any of these injuries as well.
If you can’t find it, search