High Ankle Sprain (Syndesmosis Injury): Causes, Symptoms, and Physiotherapy Treatment

If you’ve twisted your ankle and the pain feels higher up, closer to the front of your lower leg rather than around the classic outer ligaments, there’s a good chance it’s not your standard ankle sprain. Instead, you might be dealing with a high ankle sprain, also known as a syndesmosis injury.

Unlike the common lateral ankle sprain, a high ankle sprain affects the tissues that sit between your tibia and fibula, the two long bones of your lower leg. These structures keep the ankle joint stable under load, and when they’re injured, walking, running, and changing direction can become extremely difficult.

This injury is especially common in athletes, but can happen to anyone.

What Is a High Ankle Sprain (Syndesmosis Injury)?

A high ankle sprain occurs when the syndesmosis ligaments, a group of strong connective tissues between the tibia and fibula, are overstretched or torn. The most important of these is the anterior inferior tibiofibular ligament (AITFL).

These ligaments stabilise the ankle when you twist, pivot, or push off forcefully. When injured, the two leg bones can separate slightly under load, which explains why weight-bearing is so painful.

While lateral ankle sprains involve rolling the ankle outward, high ankle sprains typically happen with external rotation of the foot or strong dorsiflexion (toes going upward under force).

How Do People Get a High Ankle Sprain?

Syndesmosis injuries often happen during high-force movements, especially in running and field sports. Common mechanisms include:

Typical Causes

• Twisting the foot outward (external rotation) during a tackle or change of direction

• Forceful dorsiflexion, such as landing awkwardly from a jump

• Getting trapped under another player during sport

• High-impact collisions in AFL, rugby, soccer, or basketball

• Skiing accidents, where the boot locks the foot while the leg rotates

  
  

Everyday Injuries

While less common, non-sporting high ankle sprains can occur from:

• Missing a step

• Stepping into a pothole or uneven surface

• Sudden, awkward twisting injuries

  
  

Because this injury involves deeper, stronger ligaments, it often indicates a more serious ankle injury than a regular sprain.

Common Signs and Symptoms

A high ankle sprain has a distinctive pattern of symptoms that helps differentiate it from more common ankle injuries:

• Pain above the ankle joint, especially at the front

• Pain when walking, particularly during toe-off

• Difficulty weight-bearing or pushing off

• Swelling that spreads up the lower leg rather than around the ankle

• Pain with twisting or rotating the foot outward

• Feeling of instability or “giving way” under load

• Pain with calf squeeze tests or the “drive-through” syndesmosis test

  
  

Patients often describe the pain as a deep, sharp ache that flares with movement but may feel less severe at rest.

Physiotherapy Treatment for High Ankle Sprains

Because the syndesmosis stabilises the entire ankle joint, treatment must be structured, progressive, and more cautious than treatment for a normal ankle sprain.

1. Acute (Early) Management

• Offloading or temporary immobilisation (moon boot or brace)

• Reducing swelling with compression and elevation

• Crutches if weight-bearing is too painful

• Gentle pain-free activation of the calf and foot muscles

• Avoiding twisting and pivoting movements

  
  

Physios will determine whether your injury is stable or unstable, which helps guide whether you need imaging, a boot, or orthopaedic review.

2. Mid-Stage Rehabilitation

Once pain settles and the joint is stable:

• Strengthening the calf, peroneals, deep foot muscles, and tibialis posterior

• Restoring mobility, especially dorsiflexion

• Balance and proprioception retraining

• Double-leg to single-leg loading

• Introduction of controlled walking and gait retraining

  
  

This stage is crucial because poor mechanics here often lead to long-term instability.

3. Late-Stage Return to Sport / High-Level Function

For athletes or active individuals, final-stage rehab includes:

• Jogging and running progressions

• Plyometrics (hops, jumps, bounds)

• Agility drills and sport-specific movements

• Change-of-direction and acceleration work

• Load testing to ensure the syndesmosis is stable during high force

  
  

A good physiotherapy program reduces the risk of chronic ankle pain and avoids the long-term complications that syndesmosis injuries are known for.

Differential Diagnosis: What Else Looks Like a High Ankle Sprain?

Medial and lateral ankle injuries can sometimes look similar, so a physiotherapist will rule out several conditions:

1. Lateral Ankle Sprain

• Pain on the outside of the ankle

• Often from rolling the ankle inward

• Swelling is more localised

  
  

2. Medial Ankle Sprain

• Pain around the deltoid ligament on the inside of the ankle

• More likely with eversion injuries

  
  

3. Distal Fibula Fracture

• Bone tenderness on the outer lower leg

• Pain with any weight-bearing

• Must be ruled out if swelling is severe

  
  

4. Osteochondral Lesion of the Talus

• Deep joint pain, catching, or clicking

• Often coexists with ankle sprains

  
  

5. Peroneal Tendon Injury

• Pain behind or below the outer ankle bone

• Worse with side-to-side movement

  
  

6. Calf Tear (Especially Soleus)

• Pain when pushing off

• Can mimic syndesmosis symptoms in early stages

  
  

This is why early assessment by a physiotherapist is essential, getting the diagnosis wrong can lead to delayed recovery or chronic ankle instability.

A high ankle sprain (syndesmosis injury) is one of the most misunderstood ankle injuries because symptoms can be subtle initially but debilitating long-term. Fast, accurate diagnosis and structured physiotherapy treatment are the key to preventing ongoing ankle pain, instability, and delayed return to sport.

If you’re dealing with pain above the ankle, difficulty weight-bearing, or pain when twisting the leg, a physiotherapy assessment can help you get clarity and start proper rehabilitation immediately.

If you're dealing with any of these symptoms. Book with Urban Physiotherapy today! - https://urban-physiotherapy.au2.cliniko.com/bookings?business_id=423637795941128200#service