Ankle Mobility Impacts Ankle Sprains – 3 exercises to address it

Ankle mobility drills have become popular in the training world over the past few years.  As an athletic therapist, I worked extensively with football, rugby, field hockey and various other field sports and can safely say that decreased ankle mobility can contribute to both functional and athletic limitations and is an important component of any rehabilitation or injury prevention program.

Yup, I just said injury prevention and that might make you feel anxious.  How about I call it decreasing the risk of injury?  Because that is essentially the point.

The idea of injury prevention, especially for traumatic lower limb injuries such as ankle sprains, is often a subject of debate.  However, while traumatic injuries and accidents are part of the risk of sports participation, non-contact mechanisms, overuse and microtrauma are also likely to result in injury.  For example, a frequent mechanism of ankle injury in football involves the foot planting on the playing surface with the body rotating in the opposite direction, such as when decelerating and/or changing direction.

Injury prevention is a term that refers to implementing structure and strategies that reduce injury risk, occurrence and severity.  Fundamentally, range of motion, motor control and strength play a role in injury prevention because they provide athletes with the capacity to absorb, distribute and transfer forces along the kinetic chain.  

Let’s dive into why rotational mobility of the ankle plays a role in the prevention of ankle sprains and how to specifically improve it.

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HIGH ANKLE SPRAINS – HOW DO THEY HAPPEN?

High ankle sprains, or syndesmotic ankle sprains, are less frequent than lateral ankle sprains, but according to Prentice, are more common than has been realized in the past (1).  This type of ankle sprain occurs with excessive external rotation or forced dorsiflexion of the ankle and may be injured in conjunction with the medial ankle ligaments.

External rotation seems to bring the most opportunity for syndesmosis injury by widening the ankle mortise (2) , a hinge joint that is formed by the tibia and fibula:

The talus sits between the medial and lateral malleoli and normally does not rotate substantially.   However, with a great enough external rotation force to the forefoot, the talus is forced to rotate laterally, pushing the fibula externally away from the tibia, resulting in a twisting injury to the ankle.

In the sports environment, this can occur during deceleration and/or change of direction, both movements during which the ankle must absorb external rotation.  While it takes more than the forces of deceleration for a high ankle sprain to occur, we will see how mobility plays an important role in absorbing these torsional forces.

HOW DOES ANKLE MOBILITY PLAY A ROLE?

The complex biomechanics of the foot and ankle is that of multi-axial motions occurring simultaneously.  The foot and ankle complex is the first point of contact that acts to dissipate external forces and absorb ground reaction forces, generate forces for propulsion and provide a stable platform to transition between absorption and propulsion.

When an athlete decelerates or changes direction, the external rotation force created at the ankle is absorbed via dorsiflexion, abduction and eversion, or what we commonly refer to as pronation.

In training, we tend to focus on preventing or controlling excessive pronation because it is associated with increased knee valgus for movements like squats, lunges and the likes.  But remember, 

lack of mobility is not stability

In a dynamic sports environment, if the foot and ankle complex is rigid and cannot pronate, this impacts the ability to absorb torsional forces.  From an injury prevention perspective it is imperative that we restore and maintain the natural mobility of the foot and ankle complex, as it acts as a torsion-dissipating mechanism for movements commonly encountered in sports.

Studies even suggest that this natural rotational mobility of the foot and ankle complex should be considered in the study of footwear and foot orthotics, such as in the use of stiff vs flexible shoes in football (3, 4).

RESTORING SPECIFIC ANKLE MOBILITY

Before I go into my strategy to restore specific ankle mobility, I want to start by saying that unless you are working with an athlete post-injury or post-immobilization, you should not expect gross changes in ankle mobility.  

There is no consensus on what the “best” amount of mobility is, and different athletes with different levels of mobility will simply manage landing and decelerating tasks accordingly

However, previous injury can create restrictions and side-to-side imbalances, which is really what you are looking for in your assessment and what you are looking to improve.

Moving along, while the more popular ankle mobility exercises tend to focus on dorsiflexion, it is only one of the movements involved in the absorption capacity of the foot and ankle complex.

As discussed earlier in this article, the ankle absorbs torsional forces via dorsiflexion, abduction and eversion.  Again, these are multiaxial motions occurring simultaneously, not in a single plane.  This should be taken into consideration in the selection of self-mobilization exercises.

In the Mobilization sequence of your intervention, your objective is to create space.  With a restricted ankle, a good place to start is with a banded distraction, which will serve to increase general mobility. I have athletes mobilize for 1 to 2 minutes with moderate to heavy band traction, either creating oscillation by moving back and forth, or holding the distracted position:

We can then follow up with a mobilization with movement, using a wedge to mobilize specifically in dorsiflexion, abduction and eversion. The band helps mobilize the talus in a postero-medial direction and the use of the wedge increases abduction and eversion. For this drill, I have the athlete move in and out of dorsiflexion, with varying degrees of tibial internal rotation (progressively moving the knee towards the big toe) for 1 to 2 min:

MAKE SURE TO WATCH THE MAIN VIDEO OF THIS ARTICLE FOR MORE ON THESE EXERCISES

WHAT ELSE?

Truthfully, even specific mobilization exercises won’t make much impact if you don’t integrate loaded strategies to restore the functional demands of absorption, propulsion and stability.  

Hint: these strategies will be the focus of a subsequent article.

That said, one of the most important things we do after increasing ankle range of motion is work on sensorimotor control.  In addition to absorbing, distributing and transferring forces, the ankle needs to react to uneven surfaces and/or the center of mass moving outside of the base of support.  

This means the ankle needs good proprioceptive capacities and a very low threshold to detect passive motion so that it can react to quick, unanticipated inversion and eversion moments.

Unfortunately, standing on a BOSU ball only trains slow, anticipated inversion and eversion moments.

In the dynamic sports environment, demands are placed on the proprioceptive, visual and vestibular system in an uneven, constantly changing distribution.  Priming the visual and vestibular system is key in the Activation sequence.

I also discuss this at length in my article: Ankle Sprains – 3 Key Rehab Exercises so make sure to give that a read.

BEFORE YOU GO…THERE’S MORE

Just because you have restored range of motion and sensorimotor control, does not mean your athletes are ready to return to play.  Whenever we increase range of motion, we need to load the joint safely to ensure this range is exploited.  

Enhancing range of motion without exploiting it is leaving half the job undone

Too often, conventional rehab exercises fall short of replicating the actual strength demands that will be imposed on the ankle in a dynamic sports environment.  We need to prepare the ankle to actually absorb and tolerate load. After all, during running, ground reaction force has been shown to increase to more than 2.5 times body weight.  

This requires specificity in regard to HOW loads are absorbed, distributed and transferred along the kinetic chain.  Because tissues and structures that have not been subjected to stress levels similar to those encountered during sport-specific situations are at greater risk of injury (or re-injury).  

Can’t wait to find out more?  Make sure you keep an eye out on the blog for our upcoming article on this!

REFERENCES

(1) Prentice, William E.. Rehabilitation Techniques for Sports Medicine and Athletic Training (p. 1764). SLACK Incorporated. Kindle Edition.

(2) Norkus, S. A., & Floyd, R. T. (2001). The anatomy and mechanisms of syndesmotic ankle sprains. Journal of athletic training, 36(1), 68–73.

(3) Button, K. D., Braman, J. E., Davison, M. A., Wei, F., Schaeffer, M. C., & Haut, R. C. (2015). Rotational stiffness of American football shoes affects ankle biomechanics and injury severity. Journal of biomechanical engineering, 137(6), 061004. https://doi.org/10.1115/1.4029979

(4) Lundberg, A., Svensson, O. K., Bylund, C., Goldie, I., & Selvik, G. (1989). Kinematics of the Ankle/Foot Complex—Part 2: Pronation and Supination. Foot & Ankle, 9(5), 248–253. https://doi.org/10.1177/107110078900900508

Mai-Linh Dovan M.SC., CAT(C)
Certified Athletic Therapist
Founder of Rehab-U