Hello Posterior Tibialis

Most runners at one point or another have suffered from an ankle or foot injury.  Some injuries may have ranged from full blown tendinitis, a stress fracture, sprain, or just ambiguous soreness.  It is easy to overlook the feet, rather than pay a little more attention to them.

The foot itself is a rather complex structure. 26 bones, 33 joint, 6 main nerve branches, 19 muscles, and 107 ligaments make up the foot. Safe to say, there are a lot issues that help make up our feet and essentially allow to propel our heavy bodies just with walking. They should be strong and flexibility at the same time, and then one of those components is missing, people start getting into trouble. When we add running into the mix, it is clear to see how important foot and ankle stability, strength, and endurance are for our training and performance. In terms of strengthening the foot and ankle, it is better to first pay attention to the bigger ones which are crucial in helping maintain shape and also manage stress and flexibility of the foot.

 Lets recall that the most frequent running related injuries are medial tibial stress syndrome (shin splints), Achilles tendinopathy, plantar fasciitis, and patellar tendinitis (1).   When we take a look at the bigger picture in order to explain why these injuries develop , clinically therapists will usually find deficiencies in hip strength and ankle/foot strength. When looking at the ankle and foot, the weaknesses that are most commonly seen are in the posterior tibialis, and fibularis longus muscles. Weaknesses in these areas end up causing biomechanical alterations in the whole lower quarter during regular walking gait, and more so during running. Over time, if the weakness persists the repetitive strain will lead to injuries. 

The role of posterior tibialis muscle is to plantarflex (point foot down) and invert (point foot inwards)  it also helps to keep the midfoot (arch of the foot) from falling too far down towards the ground. The fibularis longs (or peroneus longus) is in charge of plantar flexing and everting (point the foot out) the foot.  Therefore is the posterior tibias for instance is not strong enough to carry out its role, it will cause excessive mid foot drop, which will pull your knee and hip inward. 

 In a study conducted in 2001 by Bennett et al, they found that in a group of 125 cross country runners, the ones who developed medial tibial stress syndromes (shin splints) were the ones who demonstrated increase midfoot pronation (1).  Well, what typically causes midfoot pronation? Sometimes the way you are structurally built influences foot position.  Individuals with naturally lower arches are more likely to exhibit excessive pronation and are 3x more likely to experience posterior tibialis tendinitis, compared to individuals with high arches (3).  But to keep it clean and simple, it is common to find a weakness of the posterior tibialis muscle in individuals that demonstrate excess mid foot pronation. Neville et al, also demonstrated that subjects with posterior tibial tendonitis had significantly lengthened tendon/muscle (it is hard to say which is truly lengthened) and increase midfoot pronation compared to the healthy group. The individuals with tendonitis demonstrated lower function, and mobility during gait especially during the loading phase and push off phase (terminal stance) overall.

In a runner, weakness of the posterior tibialis can really cause havoc. How can you expect to run30 + minute runs and repetitively stress the arch of your foot as well of the muscles without eventual consequences. 

Traditional foot strengthening exercises usually involve curling the toes, picking up marbles, curling towels or something of that sort.  Which is okay, but how does that directly translate over to running gait? It would be more ideal to practice the short foot position in weight bearing exercises, such as heel raises, single leg heel raises, squats, single leg squat, single leg balance, sidesteps instead.

 

Train smart, take care of your body, take care of your feet

Happy running, 

Jessica L. Mena PT, DPT, CSCS

 Posterior tibialis exercise with a theraband: Some people do the pointing down of the foot and holding for a second and going for repetitions. I tested this the last few weeks with with prolonged 30 seconds holds and really found that much more effective. With a moderately difficulty resistance, point the foot and toes doing and inward - without moving the   lower leg and knee- and hold for 30 sec, break for 10 sec and repeat x5 .  This should be a warm up before a gym work out or run. 

Posterior tibialis exercise with a theraband: Some people do the pointing down of the foot and holding for a second and going for repetitions. I tested this the last few weeks with with prolonged 30 seconds holds and really found that much more effective. With a moderately difficulty resistance, point the foot and toes doing and inward - without moving the   lower leg and knee- and hold for 30 sec, break for 10 sec and repeat x5 .  This should be a warm up before a gym work out or run. 

Short foot: When doing this technique/exercise you want to begin by understand that the goal is to apply only 3 points of contact from the foot into the ground. There is a point of contact under the base of the big toe, under the base of the small toe and the heel. From there, attempt to lift the mid foot up and off of the ground, by gently pressing down with your big toe  without scrunching your toes or lifting your heel. Once you get the hang of that concept and the ability to raise your arch, progress to maintaining the short foot with 

1. Seated Heel raises: you will raise onto the ball of your feet and over your big toe and return slowly

2. Standing short foot with Single leg balance , to make it harder single leg balance with reaching forward and back with the opposite leg. (use cones as targets) 

3. Double leg squat with short foot. 

This takes a lot of time and practice, be patient and remember that quality over quantity is what matters initially, you can progress quantity once you get the form down. 

Think about working on your short foot when your are waiting in line, brushing your teeth, showering, or working out at the gym. 

 Image above is one of my self. The Bottom left image is my weight bearing right foot, and you can see that compared to right image of my weight bearing left foot, the inner aspect of my mid foot is different. In the left image my right mid foot drops compared to the picture of the right where you don't see that on my left foot. I was asymptomic for months until I started running 18 + miles, i ended up developing foot pain.  Imagine all the strain my foot endured every step I took and landed like the picture on the right? 

Image above is one of my self. The Bottom left image is my weight bearing right foot, and you can see that compared to right image of my weight bearing left foot, the inner aspect of my mid foot is different. In the left image my right mid foot drops compared to the picture of the right where you don't see that on my left foot. I was asymptomic for months until I started running 18 + miles, i ended up developing foot pain.  Imagine all the strain my foot endured every step I took and landed like the picture on the right? 

1. Bennett J.E., Reinking M.F., Pluemer B., Pentel A., Seaton M., Killian C. Factors Contributing to the Development of Medial Tibial Stress Syndrome in High School Runners. Journal of Sports Physical Therapy. 2001.  31 (9) 504-510

2. Chimenti, RC., Flemister, S.A., Tome, J., McManhon J.M., Houch J.R. Patients with Insertional Achilles Tendinopathy Exhibit Differences in Ankle Biomechanics as Opposed to Strength and Range of Motion.  Journal of Sports Physical Therapy, 2016. Vol 46:12 pg 1051- 1060

3. Neville, C., Flemister A., Tome J., Houck J. Comparison of Changes in Posterior Tibialis Muscle length between subjects With Posterior Tibial Tendon Dysfunction and Healthy Controls During Walking. Journal of Sports Physical Therapy. 2007 Vol 37:11.