Patients present with medial ankle pain all the time, and typically the location alone gives us a working diagnosis of Posterior Tendon Injury. However, proper muscle testing may reveal a strong and painless PosteriorTibialTendon, but a painful FDL or FHL. I have seen so many FHL injuries in my career, as it seems to be picked on to help ankle plantarflexion when the achilles is weak (post injury or post surgery). I do not think this is a great video for doctors however. The tests are all fine, but they give the patient the advantage since the tendon is shortened before strength testing.
This concept in muscle testing can really pick up subtle weaknesses and, sometimes, the only way you find pain in the tendon. So, let’s review. When you test a muscle that is shortened, you give it tone, thus you give the patient the advantage. Therefore, if they are weak, you temporarily put them in their best position to use the tendon, and you may not find that weakness. When you test a muscle that is stretched out somewhat, you temporarily weaken that tendon, and you may find subtle weaknesses or pain. In this way, I have been able to differentiate between these 3 tendons.
So, for each tendon how do we test so that we give the patient the advantage (their strongest side or some temporary super powers) or give the patient a disadvantage (their weaker version like placing kryptonite next to them). When you give the patient the disadvantage, you actually discuss in terms of you having the advantage.
- Posterior Tibial Function Ankle Plantar flexion and foot adduction
Test with patient advantage. Have patient ankle plantarflexed and at subtalar neutral or slightly inverted and have them plantarflex and adduct against your hand
Test with the patient at a disadvantage. Have patient ankle plantarflexed and at subtalar joint maximally pronated and have them adduct against your hand to subtalar joint neutral
- FHL Function Ankle Plantarflexin and big toe flexion
Test with patient advantage. Have patient in ankle plantarflexion and hallux at 1st MPJ neutral or slightly plantarflexed and have them plantarflex the toe into your hand
Test with patient at a disadvantage. Have patient in ankle dorsiflexion as far as possible and dorsiflex Hallux as far as possible and then have them plantarflex the toe into your hand
- FDL Function Ankle Plantarflexion and lesser toes flexion
Test with patient advantage. Have patient ankle in ankle plantarflexion and lesser digits in MPJ neutral Have them flex the toes against your hand, ideally one at a time
Test with patient at a disadvantage. Have the patient in ankle dorsiflexion as far as possible and dorsiflex the lesser toes as far as possible and then have them plantarflex the toes into your hand, ideally one toe at a time
The anterior tibial is mentioned here only now to bring up one point. When you have a patient with posterior tibial tendon syndrome, and you are trying to strengthen it, always review how they are doing their strengthening. Of course, it should be from the same positions you test it. However, in my experience, 80% of my patients are strengthening their anterior tibial tendon instead of their posterior tibial tendon with an inversion and adduction foot motion, but with the ankle at neutral (not plantarflexed). Please check.
