Pain on the inside of the ankle when running? Maybe just at the start and end of a run? Or not even a pain – just a niggle? Don’t overlook it. It could be Tibialis Posterior Tendonitis.
What is Tibialis Posterior Tendonitis?
Well, the Tibialis Posterior muscle is one of the deep calf muscles found in the back of the leg. It helps your Gastrocnemius and Soleus muscles to plantarflex the ankle (i.e. point the foot away, or lift up on to tip toes when standing). It also acts to invert the foot (also known as supinate) – meaning to turn the sole of the foot inwards.
Whilst the belly of the muscle is located deep in the calf, the tendon passes down to run behind the inner ankle bone (medial malleolus). It then travels down below it and on to the Navicular and Medial Cuneiform bones of the foot. It is this area which becomes injured in cases of Tibialis Posterior Tendonitis.
As with many conditions labelled ‘Tendonitis’, this name is now thought to be inaccurate as the ‘itis’ suffix suggests an inflammatory element. Research has shown inflammation to not be the main pathology of the injury. Degeneration of the tendon’s collagen fibres is a more likely culprit. A better term to use when describing this and similar conditions is Tendinopathy.
- Niggly pain on the inside of the ankle and into the foot
- Initially at the start of a run and again when finishing
- Tender to press around the inner ankle bone
- As it progresses pain lasts longer into runs and may be continuous
- Discomfort turn the sole of the foot outwards (eversion) as this stretches the tendon
- There may be some pain on contracting the Tibialis Posterior against resistance in more severe cases – plantarflexion with inversion.
- The calf muscles may feel ‘tight’ and there may be less dorsiflexion (pulling the foot upwards) than on the other ankle.
Causes of Tibialis Posterior Tendonitis in Runners
As mentioned above, Tibialis Posterior (tib post) acts to plantarflex and invert (supinate) the foot. These are the actions the muscle performs whilst shortening as it contracts. This is known as a concentric contraction.
However, muscles can also perform what’s known as an eccentric contraction and these are much harder work for the muscle and tendon as a unit. What happens with this type of contraction, is that as the muscle contracts, it lengthens. Eccentric contractions occur to help control and slow down a movement against gravity or momentum for example.
So in the case of our feet when running, Tibialis Posterior will act to slow down the movement of eversion (also known as pronation) as we go from heel strike to toe off. So, in those of us who overpronate, or pronate very rapidly – Tib post has to work pretty hard to help control this movement. The result in many cases is degeneration of the tendon.
As with pretty much all running injuries, the first step is to rest. Continuing to run on it will only make it worse and mean you need an extended rest period in the long run. However, rest alone won’t be enough. The injury happened for a reason and you need to establish what that reason is and correct it BEFORE returning to running.
In order to help the tendon rest, if you are on your feet all day, I would recommend taping the foot to unload the tendon by reducing the amount of pronation available. Also wearing good supportive shoes will help with this. No flip flops, ballet shoes or Ugg boots please!
So, as mentioned above, Overpronation is one of the biggest causes of this condition. If you already know you overpronate, then consider if you have been wearing the right type of running shoes? Or if you might be overdue a new pair or if anything else has changed in your training and lifestyle which could put extra stress on that tendon. A new job where you walk more maybe? Less supportive shoes on a daily basis?
If you are not sure, or didn’t think you did overpronate, then I would recommend a gait analysis. This will show you how much your pronate and if it is excessive. It may be as simple as a new pair of running shoes or inserts in your current ones.
Strengthening for Tibialis Posterior Tendinopathy
Strengthening is really key to this injury in order to prevent it coming back. And it really is the type of strengthening you are doing that is important. As the tendon is overworked in an eccentric manor, it is this type of contraction you should be working on strengthening.
Tibialis Posterior is a plantarflexor and inverter when it works concentrically, which means that in order to work it eccentrically we must control movements in the opposite direction. This is why eccentric heel drops and eversion on a step are great exercises for this condition:
Eccentric Heel Drop:
- Stand on a step with the heels hanging off the back
- Lift up on to the toes (using both legs)
- Take the weight onto the injured leg only
- Slowly lower the heel back down below the step under as much control as possible
- Put the other foot on the step and lift back up onto the toes and repeat.
- To make it even more specific, you can reduce the effect that Gastrocnemius has by performing this exercise with the knee slightly bent.
Eversion on a Step:
- Stand sideways on a step so that the inside of the foot is just over the edge
- Very slowly roll the arch of the foot inwards, as if trying to get the big toe down to the floor
- Reverse the movement to bring you back up to the starting position.
Resistance (rehab) bands are also good for Tibialis Posterior strengthening as the foot can be moved into inversion to strengthen concentrically and then controlled very slowly back to the starting position to work the eccentric element.
Stretching Tibialis Posterior
Tight calf muscles (and so Tib Post too) can increase the amount and speed of pronation (inversion). Stretching the calf muscles on a regular basis (minimum x3 a day) can really help with reducing pronation whist running.
Make sure you stretch Soleus and Tibialis Posterior by performing a calf stretch with a bent knee. You can also place more emphasis on Tib post by adducting the knee slightly (moving it inwards towards the other leg) when in a Soleus stretch position.
Returning to Running
Only return to running following Tibialis posterior tendinopathy when:
- you have absolutely no pain day-to-day;
- It is no longer tender to press around the inner ankle bone
- There is no pain on stretching or contracting the Tib Post muscle
- You have addressed any running shoe issues
- You have seen good improvements in your eccentric strengthening exercises
- You have full ankle range of motion (especially dorsiflexion with the knee bent)
At this point, you are able to try a very short run. I would advise trying on a treadmill first as they allow you to stop immediately if you do feel any discomfort. When running outside, you need to get back to where you started from so there is always a temptation to just carry on.
Start with a 10 minute jog, provided everything feels ok. Don’t be tempted to do more than this. Then I would always advise you to have at least one full day’s rest to ensure there is no delayed response to the run before trying again – another 10 minute run. If this is ok, try a little longer the next time – 20 minutes max. Continue to increase in this manor whilst continuing exercises. If you feel are recurrence of the injury, then stop immediately and re-assess.