Posterior tibial tendonitis

Posterior tibial tendonitis is an often painful condition with localised swelling and pain over the medial side of the foot around the ankle and extending to the navicular.

This tendon starts as a muscle deep behind the leg and moves around the medial malleolus (ankle), attaching as a tendon to the navicular, medial cuneiform and first ray.

The pain can extend up around the ankle as well as over the navicular bone on the medial side of the foot. It can also present in the lower one third of the leg as what was formally known as ‘shin splints‘.

The tendon assists the foot to re-supinate and to slow down mid-stance pronation. It plays a supporting role in the arch.

Causes of posterior tibial tendonitis

Should the foot be over-pronating, the posterior tendon will over-work in its effort to prevent this. Those who pronate excessively may be prone to this condition, and it manifests more frequently in active people. Long distance runners who pronate excessively can stress the posterior tendon.

The condition can have many levels of severity. It can start initially as a mild hypertrophy (enlargement of the muscle body) as the muscle becomes over-worked and adapts.

It may then develop into micro tears in the muscle body that heal with scarring and fibrous tissue. This type of muscle is thickened and less flexible, and does not function as strong as it should.

As the condition progresses, it can develop into periosteal tears, where periostium separates from the bone. Then even further into stress fracture.

Treatment for posterior tibial tendonitis

  • Treatment involves a biomechanical assessment to confirm the cause of the faulty foot function.
  • Stretching, insoles or orthotics to support the foot will relieve the stress on this tendon effectively.
  • Soft tissue mobilisation and massage will assist in rehabilitating the muscle back to function. This may take a few sessions, depending on the state of the muscle.
  • Non-steroidal anti-inflammatories may relieve pain, although one should not depend on this form of treatment to solve the problem. Reducing pain can make you feel that it has gone away, but the condition will worsen in time.

In severe cases, mostly in the elderly who have dropped arches, the tendon may rupture or severely over-stretch, leading to a total collapse of the foot architecture. This makes treatment more difficult. But some cases may respond to appropriate orthotics and footwear therapy.