The tibialis posterior muscle originates from your shin bone, runs around the inside of your ankle and attaches to the bones in your foot at the top of your arch.
The role of this muscle is key in assisting other ligaments and muscles to hold up your arch (i.e. stop the foot from flattening out).
What is it?
When this muscle is repetitively overused/overstretched it can result in a painful condition known as posterior tibial tendon dysfunction (PTTD).
Basically the posterior tibial muscle/tendon unit becomes weakened, and there is a consequent loss of control over the foot. This can result in the foot acquiring a more flattened appearance, which can become quite disabling.
There are three main stages of this condition:
- Inflammation of tendon and mild tendon degeneration
Mild to moderate pain along the inner ankle, worse with activity
- Muscle weakens, arch begins to flatten and forefoot turns out
Increased pain and inflammation
- Tendon very stretched/ruptured, virtually no strength left in muscle
Secondary arthritic changes, the foot becomes fixed in a rigid deformed/flattened position.
What does it feel like?
Pain along inside of the ankle
Progressive collapse of arch in foot
Feeling of weakness/
tiredness of foot
Swelling and warmth may be present in area around inner ankle
What causes it?
Most commonly due to many years of excessive pronation when walking (i.e. feet rolling in) as this puts an excessive strain on the posterior tibial muscle/tendon.
It can also be due to direct injury/trauma to the muscle.
Other diseases (such as rheumatoid arthritis) can weaken the tendon.
What can be done about it?
Early identification and treatment of PTTD is very important (before permanent changes occur).
Management can include:
Orthoses (to reduce stress on muscle/tendon)
Muscle stretching and strengthening
Anti-inflammatory medication or topical gels