FHL Tendinopathy

nadine stewart physio

Article by Nadine Stewart

What is FHL Tendinopathy?

FHL Tendinopathy is a condition in which pain emanates from the collagen fibres that compose the Flexor Hallucis Longus (FHL) tendon. This can occur at three locations along the length of the FHL tendon including: 

  1. Back of the ankle.
  2. Under the mid-foot.
  3. Under the base of the big toe.

FHL tendinopathy 

What is FHL Tenosynovitis?

FHL Tenosynovitis is a condition where inflammation or swelling occurs to the sheath through which the FHL tendon passes. Often the terms FHL tendinopathy and tenosynovitis are used interchangeably as the two conditions often occur together. 

What are Tendons?

Tendons are the tough fibres that connect muscle to bone. Most tendon injuries occur near joints, such as the shoulder, elbow, knee, ankle and foot. A tendon injury may seem to happen suddenly, but usually, it is the result of many tiny tears to the tendon that have happened over time.

Who Suffers from FHL Tendinopathy and/or Tenosynovitis?

FHL Tendinopathy and Tenosynovitis occurs most commonly in a number of athletic populations where training programs involve excessive, repetitive or prolonged loading of the FHL tendon. These populations include:

  • Athletes of all ages who participate in activities requiring large amounts of forefoot push-off including: running, jumping, hopping and rising onto the toes eg. ballet dancers, long distance runners, soccer players, ice skaters, divers and gymnasts.
  • General population who have recently returned to physical activity involving large amounts of forefoot push off, or individuals who work in predominantly standing based roles including prison guards, nurses and hospitality staff.

What are the Signs and Symptoms of FHL Tendinopathy and/or Tenosynovitis?

FHL Tendinopathy and Tenosynovitis often presents with a gradual onset of pain and is less likely to occur with acute trauma, for example; a change in the type or quantity of activity in training program involving forefoot push off.

Symptoms of FHL Tendinopathy and Tenosynovitis as a result of gradual onset include:

  • Pain in the form of a dull ache that worsens to a sharp pain with activity involving forefoot push off including walking, running, jumping, hopping, rising onto the toes, demi pointe work and pointe work.
  • Pain along the length of the FHL tendon. This can occur in a number of locations including:
    • the back or inside of the ankle,
    • underneath the arch of the foot,
    • underneath the base of the big toe.
  • Swelling at the back or inside of the ankle.
  • Occasional clicking at the back or inside of the ankle.
  • Pain with movement of the big toe.
  • Potential locking or catching of the big toe if left untreated.

FHL Tendinopathy and Tenosynovitis rarely present due to acute trauma. In these very rare cases the symptoms are similar to that of an FHL Tendinopathy and Tenosynovitis resulting from overuse, however, the mechanism of injury will be different and is usually the result of a direct blunt knock to the back of the ankle.

(Brukner & Khan, 2006; Howell, 2015; Mak & Assai, 2016; Michelson & Dunn, 2005; Peters, 2015)

Why Does FHL Tendinopathy and/or Tenosynovitis Occur?

The FHL muscle is designed to assist with movement of the ankle, foot and big toe. In fact, the role of the FHL muscle is to allow the foot to point at the ankle and the big toe, as well as allowing the foot to roll in at the heel. This enables us to perform activities such as: running, jumping, hopping and rising onto the toes. 

The FHL tendon, like any other tendon in the body, becomes accustomed to a certain amount of loading to assist with movement. However, if this loading is dramatically increased over a short time period without time to adjust, or if an insult occurs to the FHL tendon that lowers its ability to tolerate load without adequate time to heal, the FHL tendon can become overused. Overuse results in damage to the collagen fibres which make up the tendon. This damage leads to the tendon being unable to perform its role, which in turn leads to further changes in the structure of the tendon, ultimately leading to pain and dysfunction.

What are the Risk Factors of FHL Tendinopathy and or Tenosynovitis?

There are a number of factors that can contribute to FHL tendinopathy and tenosynovitis including:

Intrinsic Factors

  • Poor Foot Control
  • Poor Ankle Control
  • Tight or weak musculature in the foot and leg
  • Incorrect Training Technique
  • Previous Injury

Extrinsic Factors

  • Training Activities
  • Recent Change to Training Program
  • Training Environment
  • Amount of Training
  • Training Equipment
  • Fit of shoes if required
  • Fatigue
  • Inadequate Warm Up and Cool Down

How is FHL Tendinopathy and/or Tenosynovitis Diagnosed?

A number of strategies can be used to correctly diagnose FHL Tendinopathy and Tenosynovitis. Your physiotherapist will usually ask you a number of questions regarding your injury as well as performing a number of physical tests. Imaging is another option that can also be used in the diagnosis of FHL Tendinopathy and Tenosynovitis.

Physiotherapist / GP Outcome Measures

  • Pain Description
  • Pain Location
  • History of Injury
  • Activity Levels / Changes
  • Pain Provocation
  • Functional Activities
  • Specific Muscle Tests


  • Ultrasound
  • MRI

Treatment for FHL Tendinopathy and/or Tenosynovitis


Exercise is important in the management of FHL Tendinopathy and Tenosynovitis to enable to the FHL tendon to adopt a new level of activity without an increase in pain, inflammation or further tendon degeneration. As you recover, your physiotherapist will assist you in progressing your exercise program through a number of levels based on your stage of recovery. This progression usually occurs through the utilisation of a traffic light system based on the loading that your FHL tendon can tolerate enabling a safe return to activity. You will be progressed based upon your physiotherapist's professional assessment.

Load Management, Activity Modification and Activity Prioritisation

To enable the recovery of the FHL tendon it is of great importance to participate in training and everyday activities within the limitations of the tendinopathy. As a result, you may need to temporarily modify your training activities and/or decrease the number of training sessions that you participate in. All training sessions and activities should not aggravate your pain both during and after training for 24 to 48 hours.

Stretches, Massage, Foam Rollers and Trigger Balls

Massage, foam rolling or use of a trigger ball can be used on your calves, back of the ankle and under the foot to assist with recovery by lengthening tight muscles and therefore decreasing the tension placed on the FHL tendon.

Stretches can also be performed as long as the stretch is felt across the muscle belly of the FHL (deep leg), rather than at the FHL tendon at the back of the ankle, under the arch of the foot or at the base of the big toe.

Transverse Frictions & Ultrasound

Transverse friction or tendon massage and ultrasound can both assist in the healing of FHL Tendinopathy and Tenosynovitis, as long the technique is tolerated by the individual. This occurs through the increased circulation to the damaged area.

Adjacent Joints & Lower Limb Biomechanics

Your physiotherapist will ensure that your surrounding joints and muscles are moving and activating appropriately to prevent the FHL from overworking and overloading the FHL tendon. Areas, where biomechanics are particularly important in cases of FHL Tendinopathy and Tenosynovitis, include the ankle, foot and toes.

Medications / Pharmacology

NSAIDs, corticosteroids and other pain and anti-inflammatory medications can be used in conjunction with physiotherapy to assist in the recovery of FHL Tendinopathy and Tenosynovitis by helping to settle pain and inflammation locally. Your Physiotherapist may refer you to a GP or sports doctor to discuss what medications are required in your management of FHL Tendinopathy and Tenosynovitis.


Splinting is not always required in the treatment of FHL Tendinopathy and Tenosynovitis and is generally only utilised in advanced cases.


In advanced cases of FHL Tendinopathy and Tenosynovitis surgery can be utilised as a last resort following the failure of conservative treatment strategies to reduce constriction of the tendon. If surgery is required, it is usually followed by physiotherapy to assist with rehabilitation and return to regular activity.

How is Your Treatment Rehabilitation Monitored?

Your physiotherapist will work with you to regularly assess your level of ability as you progress through your rehabilitation program. This occurs through the retesting of a number of outcome measures to determine your progress. Your physiotherapist can even work with your support team (family, boss, coach, teachers etc.) to assist with your recovery and eventual return to your regular activities.

For more information specific to your condition, please consult your physiotherapist with a spewcial interst in FHL tendinopathy.

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General Information

Heel Pain

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Foot Injuries

Bone Injuries

Degenerative Conditions

Soft Tissue Inflammation

Biomechanical Conditions

Nerve-Related Sources

FHL Tendinopathy Treatment Options

  • Early Injury Treatment
  • Avoid the HARM Factors
  • Soft Tissue Injury? What are the Healing Phases?
  • What to do after a Muscle Strain or Ligament Sprain?
  • Acupuncture and Dry Needling
  • Sub-Acute Soft Tissue Injury Treatment
  • Active Foot Posture Correction Exercises
  • Gait Analysis
  • Biomechanical Analysis
  • Balance Enhancement Exercises
  • Proprioception & Balance Exercises
  • Agility & Sport-Specific Exercises
  • Medications?
  • Orthotics
  • Soft Tissue Massage
  • Walking Boot
  • Brace or Support
  • Dry Needling
  • Electrotherapy & Local Modalities
  • Heat Packs
  • Joint Mobilisation Techniques
  • Kinesiology Tape
  • Neurodynamics
  • Physiotherapy Instrument Mobilisation (PIM)
  • Prehabilitation
  • Running Analysis
  • Strength Exercises
  • Stretching Exercises
  • Supportive Taping & Strapping
  • TENS Machine
  • Video Analysis
  • FAQs about FHL Tendinopathy

  • Common Physiotherapy Treatment Techniques
  • What is Pain?
  • Physiotherapy & Exercise
  • When Should Diagnostic Tests Be Performed?
  • Massage Styles and their Benefits
  • What Causes Post-Exercise Muscular Pain?
  • Barefoot Running: Your MUST READ Guide to the Pro's and Con's.
  • Can Kinesiology Taping Reduce Your Swelling and Bruising?
  • Heat Packs. Why Does Heat Feel So Good?
  • How Can You Prevent a Future Leg Injury?
  • How Do You Improve Your Balance?
  • How Much Treatment Will You Need?
  • Post-Run Soreness: Should You Be Concerned?
  • What are the Common Massage Therapy Techniques?
  • What are the Early Warning Signs of an Injury?
  • What is a TENS Machine?
  • What is Chronic Pain?
  • What is Nerve Pain?
  • What is Sports Physiotherapy?
  • What's the Benefit of Stretching Exercises?
  • When Can You Return to Sport?
  • Why Kinesiology Tape Helps Reduce Swelling and Bruising Quicker
  • Call PhysioWorks

    Book Online

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    Last updated 14-Feb-2019 10:39 AM

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