Reducing the Risk of Injury: Ankle Mobility

By: O2X Injury Prevention Specialist Joe Cavallaro PT, DPT, SCS, CSCS

“It depends.”

Have you heard this from a Physical Therapist or another medical provider before? It’s a common answer, and I find myself echoing this statement a lot – especially in response to the question, “what’s the best stretch for…? The question isn’t wrong, but the answer is less than helpful unless we take a look at which factors to focus on. It helps to know which are the most important factors for you to address without spending too much of your time just on preparation. This discussion will focus on ankle mobility – what it is, why it matters, and what you can do.

Most importantly – mobility is the ability of a joint to move. Each joint is connected by two or more bones, held together by ligaments, and driven by muscles. Joint range of motion is dictated by the anatomical shape of each bone and stabilized by stiff ligaments. Muscles provide the first layer of protection to limit any undue stress on the ligaments ensuring the integrity of the joint. Flexibility specifically describes the ability of a muscle to lengthen. Muscles need to lengthen enough to not restrict full joint range of motion but strong enough to provide stability at the end-range of movement.

Whether you serve in the military, law enforcement, fire, or emergency medical service, I’ll make the assumption that you have a solid understanding of each piece of equipment you work with – what it does, how it functions, and when to use it. At a recent drill weekend with an infantry unit from the Army National Guard in Massachusetts, I observed soldiers spending hours preparing for their individual weapons qualification. As they moved through the training stages, they repeatedly assessed the functions of their weapons, practiced positioning and movement, and corrected malfunctions. Professionals spend countless time ensuring that mission essential equipment functions optimally because their job and often their safety depends on it. It should make sense that we take the same care in ensuring our bodies function optimally for the same reasons.

Structure and Function

The ankle joint is formed where the parallel bones of the lower leg, the tibia and fibula, connect to the top of the talus bone, a dome-shaped bone at the top of the foot. A rudder-shaped heel bone, the calcaneus, sits below the talus. In front of these two are the remaining tarsals, metatarsals, and phalanges that make up the rest of the foot.

Ankle stability is provided by strong ligaments, which allow for motion in specific directions and restrict motion in others, while forward movement from the ankle is powered primarily by the large calf muscles – the gastrocnemius and soleus. Smaller but more important muscles also cross the ankle joint from the lower leg and help coordinate movement with the foot. Some of these muscles run all the way to your toes. They may be small, but their health and function play a vital role in ankle function.

The main functions of your ankle joint are propulsion and accommodation. Propulsion creates forward movement – think walking and running. The second function, accommodation, is the ability to adjust to the terrain surface and absorb forces from the ground.