Foot pain on the inside of the ankle running down into the arch, is commonly caused by an injury to the posterior tibial tendon, one of the most important tendons in the foot.
The posterior tibial tendon provides stability and support to the arch on the inside of the foot when standing and walking, and is particularly active when running.
The posterior tibial tendon is are made up of collagen strands, similar to a nylon rope. Some of the individual strands of the tendon can become worn and knotted because of degeneration. Other fibers can tear and/or break, and the tendon loses its strength and ability to function.
Tendon injury occurs when the posterior tibial tendon becomes dysfunctional, inflamed, overstretched or torn. When this tendon is injured it is unable to provide stability and support for the arch of the foot, resulting in the most common cause of acquired flat foot.
Posterior tibial tendon injury can be acute in nature, due to a high force going through the tendon beyond what it can withstand, for example a tear or sprain during physical activity.However injury due to gradual wear and tear, associated with degeneration and overuse is more commonly encountered.
Therefore posterior tibial tendon injury occurs more frequently in women and people over 40 years of age. Additional risk factors include obesity, diabetes, and poor training techniques.
Causes of Posterior Tibial Tendon Injury:
- Acute trauma due to a forceful contraction of the tibialis posterior muscle, often when in a position of stretch (i.e. rapid acceleration whilst running, particularly when changing direction).
- Overuse injury due to repetitive or prolonged activities placing strain on the posterior tibial tendon (i.e.running especially uphill, hiking, stair climbing).
- Poor foot biomechanics (flat feet) and/or inappropriate footwear.
- Recent increase in training or activity..
- Degeneration and weakening of the tendon (hormonal changes, age, medication).
Symptoms of Posterior Tibial Tendon Injury:
- Pain and/or swelling along the inside of the foot, arch and ankle bone, where the tendon runs and inserts.
- Pain may also be experienced on the outside of the ankle in chronic cases as the foot collapses and causes impingement on the outside of the ankle bones.
- Gradual onset which progressively worsens over time with continuation of aggravating weight bearing, especially under high intensity or impact.
- Trouble walking or standing for a long time, with aching and muscle fatigue.
- Difficulty with/unable to stand on one leg and rise up onto tiptoes on the injured side.
- Collapsed or fallen arch over time if the tendon is torn or not functioning properly.
- Complete rupture will produce a pronounced flat foot.
- Thickened tendon due to scar tissue from wear and tear.
- Nodules or knots within the tendon, causing areas of weakness.
Treatment for Posterior Tibial Tendon Injury:
Treatment should be started as soon a possible to enhance recovery. If left untreated, posterior tibial tendon injury may lead to irreversible damage, such as a inflexible flat foot and painful arthritis.
- R.I.C.E (rest, ice, compress, elevate) in acute injuries.
- Anti-inflammatory medications if the tendon is truly inflamed (tendinitis).
- Cutomised foot orthotics and/or ankle bracing to correct the poor foot biomechanics and reduced load and stress placed on the tendon.
- Appropriate footwear to support the ankle and prevent rolling in of the foot, stretching the tendon.
- Rest and reduced activity to allow the tendon to recover and heal.
- Load program to strengthen the tendon, increase flexibility and balance.
- Prolotherapy to increase collagen production and strengthen the tendon.
- Dry needling to release knots in muscle and breakup nodules.
- Foot Mobilisation Therapy to help realign the foot bones and increase function.
- Soft tissue massage and joint mobilization.
- Moon boot, crutches or brace in chronic conditions or post surgery.
Note: Cortisone injection is not recommended as it may increase risk of tendon rupture
In chronic unrelenting cases, or injuries that have not responded to conservative measures after 3 months or more, may require surgery.
Surgery can involve simple repair, debridement and realignment of the tendon and surrounding sheath. However, the majority of posterior tibial tendon surgery is quite involved and may cause some limitations to movement or activity.
The surgical outcome will depend on the amount of motion available in the foot before surgery and the severity of the flat foot. The more severe the tendon injury and condition, the poorer the prognosis will be, with longer recovery times and reduced ability to return to sports. In many patients, it may be months before there is any significant improvement in pain.