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Ankle Pain

Flexor Hallucis Longus Pain

Minute Read


Posted 11 months ago


Last updated: 03/12/2022


by James McCormack

What is the Flexor Hallucis Longus?

The Flexor Hallucis Longus muscle (FHL Tendon) is a long thin muscle whose origin runs along the back of the shin bone, bending around the inner ankle and connecting at its insertion to the undersurface of the big toe. When the Flexor Hallucis Longus contracts, it pulls on the Flexor Hallucis Longus tendon to bend the big toe. The Flexor Hallucis Longus tendon sits alongside the Posterior tibial Tendon both of them play a significant role in stabilization of the foot through gait. The Flexor Hallucis Longus helps to go onto your toes. As a result, it is most often used by ballet dancers when going onto pointe.

When the Flexor Hallucis Longus tendon is overloaded it can become painful. Common conditions that lead to Flexor Hallucis Longus pain are Flexor Hallucis Longus tears and Flexor Hallucis Longus tendonitis. We will discuss these conditions and their treatment in this article.

Causes of Flexor Hallucis Longus Pain

Flexor Hallucis Longus Tear


A Flexor Hallucis Longus tear is rare and the cause of a tear can be a result of trauma, sheer forces, or when a significant amount of force is put through the muscle. A partial tear can occur when landing from a jump or through repetitive motion such as repeatedly going up onto one’s toes.


Diagnosis of a Flexor Hallucis Longus tear is achieved through an MRI or a cost-effective form of imaging is an ultrasound scan. A clinical test can be carried out of resisting flexion of the big toe. Pain on-resistance is indicative of a positive test. An x-ray is unable to detect a Flexor Hallucis Longus tear.


Symptoms of a Flexor Hallucis Longus tear is a sharp pain with activity while there is rarely pain at rest. There is often a specific incident that relates to the onset of pain. If the injury is acute there may be some swelling and bruising around the area of injury. It can be painful to jump or go onto your toes.

Flexor Hallucis Longus Tendonitis


Flexor Hallucis Longus Tendonitis (Also known as Flexor Hallucis Tendinopathy) is usually caused by a repetitive overload of the tendon. This can result in a pathological change of the tendon making it weaker than it was pre-injury. In the acute stages, there may be pain and swelling along the tendon.


Diagnosis of Flexor Hallucis Longus Tendonitis can be achieved clinically by a Physical Therapist or they may refer for an MRI to correlate with their clinical assessment.


Symptoms are often worse with activities such as running, jumping, and bending the big toe. There may be some stiffness on the tendon first thing in the morning that eases after 30-60 minutes. In less acute episodes it can be pain-free to exercise but the pain becomes more prominent afterward.

Picture diagram of Flexor Hallucis Longus Tendonitis

Treatment for Flexor Hallucis Longus Tendonitis

Physical Therapy is the most effective form of treatment for Flexor Hallucis Longus Tendonitis. This may include Load Modification such as a reduction in the activities that aggravate your symptoms such as jumping, running, or going en-pointe. It may also include increasing the rest time between activities to allow time for the tendon to recover. Reducing the number of activities you do that involve the big toe can be helpful. It is important to consider that tendon pain isn’t always at the time of activity but there may be an exacerbation of the pain within 24 hours post-exercise.

Flexor Hallucis Longus Tendonitis Taping: Your therapist may apply a rigid ankle taping. This can act to offload the Flexor Hallucis Longus tendon, providing pain relief. KT Tape is of minimal to no benefit for FHL Tendonitis. A Gait Analysis through video analysis of the feet, ankles, and knees can help interpret if there is an overload of the Flexor Hallucis Longus tendon. Custom insoles or orthotics: Custom insoles can be created by a therapist after gait analysis. They will be tailored made to offload the Flexor Hallucis Longus tendon, leading to a reduction in pain levels.

In some cases, a walking boot is required if rehabilitation is not effective due to high pain levels.  Using a walking boot can help reduce pain levels before reintroducing strengthening exercises. Steroid injections are generally avoided where possible for any form of tendonitis and they can be harmful to the tendon in the longer term.

Flexor Hallucis Longus Tendonitis: Exercises

Flexor Hallucis Longus Tendon Band Strengthening

  • Wrap a resistance band around the big toe
  • Lower the big toe to the floor against the resistance band keeping the other toes still
  • Slowly release the big toe up

Flexor Hallucis Longus Tendon Strengthening

  • Place a foot on a towel in sitting then curl the toes down to pick up the towel
  • Raise the forefoot off the floor
  • Lower the foot to the floor

Flexor Hallucis Longus Tendon: Heel Raise

  • Place a rolled towel under the big toe while balancing on the foot
  • Raise the heel up keeping the foot straight
  • Slowly lower the heel down

Physiotherapy with James McCormack

This is not medical advice and we recommend a consultation with a medical professional such as James McCormack to achieve a diagnosis. He offers Online Physiotherapy Appointments for £45.

Why does my Flexor Hallucis hurt?

It is likely that you have pain in the Flexor Hallucis due to a muscle tear or as a result of Flexor Hallucis Tendonitis. A tear is usually sudden in onset with a specific mechanism or injury while tendonitis is caused by an overload with no specific incident causing the pain.

How do you fix Flexor Hallucis Longus pain?

Physical Therapy consisting of stretching and strengthening exercises is the most effective form of treatment for Flexor Hallucis Tendonitis. Home treatment might include anti-inflammatories, icing, reducing use of the big toe and wearing stability shoes.

How do you release the Flexor Hallucis Longus?

You can self-release the Flexor Hallucis Longus by foam rolling the inner side of your shin along the muscle belly of the Flexor Hallucis Longus. A massage gun can be used with the same principle. Other methods include stretching your big toe or applying direct pressure to the muscle belly of the Flexor Hallucis Longus while flexing and extending the big toe.

How long does FHL Tendonitis take to heel?

It takes approximately 6-12 weeks for FHL Tendonitis to heal through a graded strengthening program. It is unlikely to heal on its own and can last longer than 12 weeks without the appropriate treatment from a Physical Therapist.

How do you stretch the Flexor Hallucis Longus?

To stretch your Flexor Hallucis Longus place your big toe up against a step so that the toe is extended as much as comfortable. Maintain this position and move your knee over your foot while keeping your heel on the floor until you feel a stretch on the inside of your ankle r the underside of your foot.

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