so everyone in this video we're going to look at a super important muscle the tibialis posterior muscle I'm going to talk about the anatomy of this muscle and the clinical implications that we see when this muscle is problematic in practice if you're ready to learn let's dive in so everyone let's dive into the main muscle of today's talk which is of course the tibialis posterior muscle now as the name would suggest tibialis posterior we can see how this muscle runs down the posterior aspect of the tibia before it swoops to the medial side but one thing that is really important to mention is how the tendon actually starts a lot higher up the tibia than you may have first thought in fact it's almost 2/3 of the way down the tibia that the tendon starts rather than right down by the ankle that's a really important point so let's head into the origin and if we Fade Out this muscle we can see that it originates from the posterior surface of the proximal tibia as well as the posterior surface of the proximal fibula and as you can see in blue the interus membrane which sits between the tibia and the fibula so then the tibialis posterior muscle runs down the posterior tibia as we said and swoops down towards the medial ankle here it runs through a really important structure which is the tarel tunnel which sits between the medial malleolus of the ankle and the medial calanus and we can remember of course that the tarel tunnel has the flexor retinaculum in blue over the top of it which almost holds the tibialis posterior tendon down against that area to stop it from fraying too far medially now it's really important to note that the tibialis posterior tendon runs through the tarel tunnel and underneath the medial malis because it means that this part of the bone almost acts as a lever point for the tibialis posterior to work against in order to perform its roles when it contracts so after it Loops inferiorly underneath the medium molis we can see how it almost runs horizontally towards its insertion points on the medial and planter surfaces of the foot now it does have a number of different insertion points the first and perhaps its most important one is referred to as the nvic tuberosity which naturally is a part of the navicular bone this is suggested to be the main insertion point for tibialis posterior the tendon then continues to run underneath to the planter surface of the foot and we we fade the tendon out we can see how it attaches to the three uniform bones and the bases of metatarsals 2 3 and four meaning that when it has such a huge insertion point it must have a really important role on to nerve Supply and the nerve supply for this muscle comes from the tibial nerve from the nerve Roots L4 and L5 and then we come to the all important roles of this muscle its movement-based roles include planter flexion of the ankle and inversion of the ankle at this point I would like to mention one of the other key inverters of the Foot and Ankle which is the tibialis anterior muscle notice how this muscle runs over the dorsum of the foot and inserts into the medial uniform and the base of the first metat tasel this allows us to consider that when the foot is in a plant Flex position the main inverter of the ankle will be tibialis posterior but when the foot is in a dorsiflex position the main inverter will be tibialis anterior this is so important for our rehab when we consider what position we want the foot to be in when our patient is doing that rehab now in terms of today's topic we come to the most important additional role of tibialis posterior which is to act as a dynamic stabilizer of the medial longitudinal arch of the foot when we are walking so what is the medial longitudinal Arch this is the set of bones of the taus the calanus the navicular the three uniforms and the first three metatarsals all located on the medial side of the foot and this creates a height to the medial foot it is really important that we maintain the integrity and shape of this Arch as we walk as it allows for more speed and more natural power but also because a lack of arch leads to increased flattening of the foot and thus more weightbearing and thus degeneration of the medial foot and ankle and so once again the tibialis posterior has a huge role in maintaining the height and stabilizing this Arch during walking which means this muscle is being used with every single step we take therefore we must assess and treat our patients in a weightbearing position I this is when this muscle takes its most important role and so we must be able to work on its ability when it is doing its most important role so when do we find the tibialis posterior becomes dysfunctional in practice well there's two main things to talk about here the first is a tibialis posterior tendonopathy this is when we have an overload to the tendon which can be common in those who have suddenly increase the amount of walking or running that they're doing remember as we said in the anatomy this tendon is active with every step we take trying to maintain that media longitudinal Arch so if we are increasing the amount of running we're doing let's say a patient's training for a half marathon and suddenly they need to do a lot more running as a result we're overloading that tendon by using it more and more and more with every step that we take so no surprise if it gets tendon apathic and gets irritable because it has to perform its role with every step we take but then comes the next issue which tends to have longer and more widespread implications for our patients which is posterior tibial tendon dysfunction so as the tibialis posterior tendon starts to fail we notice that patients foot position is likely to start changing as well as you can see here on the screen when the tibialis posterior is unable to perform its role in holding up the medial arch of the foot the foot tends to collapse into a position of Pez plainness which means a flat foot over time this then develops further into a position of Pez PLO valgus where not only do we have the foot arch becoming more flat but we also have the rear foot collapsing in in a medial position this can have long-term implications for the foot because as well as losing the arch we start to develop osteoarthritis in some of the different joints especially the subtor joint and in really Progressive cases we start to see osteoarthritis in the ankle joint as well because the the fundamental position of the foot is changed with every step that we take so it's really important that we spot signs of tibialis posterior dysfunction early so that we can treat it so on that note what are some exercises that I use in practice to treat it well at the beginning in the early stages if it's really sore and irritable I have my patients in a nonwe bearing position particularly in sitting where I will give them an exercise of isometric or concentric with a theraband combined plant a flexion and inversion by taking the weightbearing element away it makes the exercise a little bit more comfortable and allow someone to get started with strengthening the tibialis posterior however as we said in the anatomy video the main roles of this muscle come when we are weightbearing so it's super important that we get our patient up in standing and put them in positions where we ask them to try and work the muscle to lift up and hold the medior longitudinal arch of the foot now in this video it might look quite subtle but by pushing down through the big toe and in particular The metatarsophalangeal Joint of my big toe I'm really working that muscle to hold up the medial longitudinal arch of the foot we can progress this further by getting our patient to move whilst trying to hold up the arch so for example this rocking backwards and forwards movement allows us to try and hold the arch whilst we're moving the body forwards and backwards meaning that tibialis posterior has to work harder and this can be progressed even further with exercises like heel Rays either in a flat position on the floor where we're trying to work the muscle in its planter flexion and inversion role perhaps here where we've got a Thera band around the calanus to try and get the muscle to work harder to perform its role of maintaining the medial longitudinal arch of the foot without allowing the foot to move into a position and we can do some really challenging stuff in the future such as putting a patient on a decline sideways on a step asking them to do things like maintaining the position of the media longitudinal arch in this position and doing a heel raise both in positions where the foot naturally wants to move into that position of PES PLO valgus which means that tibialis posterior has to work really hard to maintain the medior longitudinal arch in these positions so everyone I really hope you've enjoyed this video if you have please support us by Smashing that like button and subscribe to the channel for all our best updates we've got loads more resources for you on our Instagram account @ clinical Physio and on our membership website member. clinical physio docomo we have a fabulous tibialis posterior webinar where we go through all the key Anatomy clinical implications assessment and treatment for this muscle in tendon in loads more detail my name is car thank you so much for watching see you soon here on clinical FIA