A Navicular stress fracture is one of the most common stress fractures affecting athletes, especially those in explosive events such as sprinting and jumping. It causes a vague aching pain in the midfoot.
Medically reviewed by Dr. Chaminda Goonetilleke, 20th Jan. 2022
Navicular stress fracture symptoms
Symptoms of a navicular stress fracture include:
- A poorly localized ache in the midfoot which is worse with exercise.
- Pain often radiates along the inside arch of the foot.
- Symptoms go away quickly with rest, only to return again as training resumes.
- You may feel tenderness when you press your thumb into the top of your navicular bone. This is called the N spot.
What is a Navicular stress fracture?
A Navicular stress fracture is a hairline crack in the bone which develops gradually over time.
The navicular is one of the tarsal bones in the ankle. It sits on top of the calcaneus or heel bone.
The exact mechanism of injury is not known. However, it is thought the navicular bone gets pinched or impinged between the bones to the front and back of it. As a result, it becomes compressed.
If you have a reduced range of dorsiflexion (moving the foot upwards) in your ankle then you are more susceptible to a navicular stress fracture. This is because your midfoot has to compensate for the lack of movement.
A stress fracture of the navicular is caused by overuse or repetitive strain. For example high impact sports such as sprinting, hurdling, and jumping. Poor technique or training errors can also contribute to the likelihood of sustaining a stress fracture of the foot.
Navicular stress fracture treatment
Treatment of a navicular stress fracture depends on severity. If your injury is classed as a stress reaction, where the outer part of the bone has not fractured, then weight-bearing rest in a walking splint may be recommended. Rest until you have no painful symptoms, then gradually return to full fitness.
If a stress fracture is diagnosed then complete non-weight-bearing in a full cast for a period of 6 weeks is essential. After 6 weeks, feel the N spot over the top of your navicular. If it is tender then re-apply for a further 2 weeks non-weight-bearing.
If your navicular bone has separated, or the fracture fails to heal then you may need surgery to fix it. The bone is pinned or screwed to keep it in place.
Rehabilitation following a navicular stress fracture
Once the cast has been removed it is important to mobilize your foot and ankle. This is because your foot will have been kept still for at least 6 weeks and will be stiff.
Ankle mobility exercises and strengthening exercises should be done before starting to run again.
Calf raises and exercises for the small muscles in the foot are important
Sports massage for the calf muscles helps restore them more quickly to normal function.
It is also important to eliminate factors that may cause your injury to recur. Identify and avoid training errors such as poor technique or overtraining.
A podiatrist can check if you have any biomechanical factors such as overpronation. This is where your foot rolls in or flattens too much. It is easily corrected with orthotic shoe inserts.
Other factors include tarsal coalition, where the tarsal bones fuse together, as well as restricted ankle dorsiflexion. Both these make you more susceptible to a future navicular stress fracture.
When you have full ankle mobility and basic joint strength is restored then you can begin running again. This usually takes a week or more. Training should be very very gentle to start with. Aim to build up to normal training loads over a period of at least 6 weeks.