A fibula stress fracture is a small fracture or hairline crack in the bone. It is not as common as a stress fracture of the tibia because the fibula is not used in load bearing in the same way.
Symptoms include pain in the calf area with tenderness at a point on the fibula. Treatment includes six weeks rest and a gradual return to full training.
On this page:
- Causes & anatomy
Symptoms of a fibula stress fracture
Symptoms consist of pain in the calf area with local tenderness at a point on the fibula. Symptoms will usually have developed gradually over time, rather than a specific point in time where the athlete can recognise as when the injury occurred. There will be a pain in the lower leg on weight-bearing although this is not as painful as a stress fracture of the tibia. The pain may ease off after a period of rest but get gradually worse with exercise.
Causes & anatomy
The long bones of the lower leg are the tibia and fibula. The main function of the fibula bone is as a point of attachment for many of the muscles of the lower leg. The tibia is the thicker, weight bearing bone of the two whereas the fibula has much of its surface for muscle attachment. This results in traction and twisting forces placed on the fibula bone from the surrounding muscles,which over time cause a stress fracture.
Athletes with excessive pronation or rolling in of the feet when running are more susceptible because the peroneal muscles must work harder for longer during toe off in the running gait cycle. As the arch of the foot flattens the ankle rolls inwards, twisting the lower leg and knee. The bones in the foot are not able to take the loads as efficiently as they might which places more strain on the muscles of the lower leg, many of which attach to the fibula bone.
Overpronation and other biomechanical dysfunctions of the foot can be corrected with orthotic inserts which are placed in the patients shoes. They control the position of the heel and so enable normal foot biomechanics.
Treatment for a fibula stress fracture
What can the athlete do?
Rest from training and competition until the local bone tenderness is gone. Substitute running for swimming or focus on the upper body. Anything that works the calf muscles is not likely to allow sufficient rest to enable healing to take place.
A stress fracture is unlikely to show up on an X-ray until two or three weeks into the healing process, although a bone scan or MRI may give more information. Rest from running and other aggravating activities for a period of 6 weeks is often recommended. After the period of rest is completed a further X-ray should be taken, at which point a stress fracture may show up along the line of the fracture, seen as new bone tissue.
Wearing a heat retainer calf support will protect the muscles of the lower leg reducing the load on the fibula bone. Before returning to full activity stretching and strengthening exercises should be done on a regular base to ensure the muscles are in good condition, strong enough and flexible enough to cope with the demands of sports training. Any biomechanical dysfunction such as overpronation should be corrected to avoid the injury recurring.
Look at training methods to determine if overtraining, increasing workload too soon, or poor shoe selection is a factor. Running shoes should be good for around 400 miles or six months. After that the quality of the midsole will begin to deteriorate so the level of cusioning and support may be reduced.
What can the sports injury therapist do?
A professional thereapist may apply sports massage techniques to the muscles of the lower leg. This will help restore the condition of the muscles making them flexible and supple. A very gradual return to full training is required. They can advise on stretching and strengthening exercises for the lower leg muscles.
Fibula stress fracture exercises
Stretching exercises are more important than strengthening for recovering from a fibula stress fracture. The injury is primarily overuse so exercising the calf muscles, especially during the rest phase is not advised.
The calf muscles consist of the larger gastrocnemius muscle and the soleus muscle which is located deeper and lower down the leg. To effectively stretch both these muscles exercises should be done with the knee bent as well as straight.
To stretch the big gastrocnemius muscle the back leg must be kept straight. Stand with the leg to be stretched at the back and hands on a wall at shoulder height. Bend the front knee and lean forward, keeping the back knee straight and pushing the heel down into the floor.
When you can feel a stretch, hold for 20 seconds. If the stretch eases, lean further forwards until you can feel it again. But do not push too far in the early stages. Perform 3 repetitions and repeat this 3-5 times a day.
To stretch the deeper soleus muscle the knee of the leg to be stretched needs to be bent. This is because the soleus muscle attaches below the knee and bending the knee allows the gastrocnemius muscle to relax leaving the soleus on stretch.
Lean against a wall with the leg to be stretched at the back. Bend the knee keeping the heel in contact with the ground until a stretch is felt. Hold for 15 to 20 seconds and repeat three times. If a stretch is not felt then another method is to place the ball of the foot against the wall and bend the front knee until a stretch is felt.
Stretching on a step
As flexibility increases or if you have particularly flexible calf muscles it may be better to stretch using a step. Lower the heel off the step dropping down until a stretch is felt.
Hold for 15 to 20 seconds for 3 repetitions and repeat 3 to 5 times a day. The soleus muscle can be stretched similarly but with the knee of the leg to be stretched kept bent.