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Trends and Treatment of Chronic Ankle Instability

Perhaps it happened while playing basketball, executing a perfect arabesque, chasing the dog, or working up a sweat in an aerobics class. Everything was fine—you were going in for the winning basket of the game, you had almost caught Spot—but then you felt your ankle give way, and suddenly everything was not fine.

Ankle sprains occur frequently. Chances are, you have experienced one yourself. With the proper treatment, a full recovery can be made quickly. However, sprains weaken tendons and overstretch ligaments, which can lead to chronic ankle instability (CAI), a condition that not only causes pain but increases the likelihood of recurring injury.

To gain a greater understanding of CAI development and treatment, two exercise science graduate students, Seunguk Han (PhD) and Hyunwook Lee (MS), have measured movement of patients who experienced a first-time ankle sprain, as well as those who have developed CAI. Using a motion capture camera system to track movement, a force plate to measure ground force of movements (balancing on one foot and jumping and cutting), and small sensors attached to patients to detect muscle activity, Han and Lee have made important observations about the movement and muscular changes that occur after ankle sprain and how those can be treated.

Hyunwook Lee (MS) and Seunguk Han (PhD).
Hyunwook Lee (MS) and Seunguk Han (PhD).

“Sometimes the CAI patient and a healthy, controlled patient move similarly if we just look at their movement alone; but if we analyze a specific joint, we can see the differences,” Han says. “Some of the CAI patients perform well when they jump and land, or do the side cutting movement, but when we analyze their movement, we can see that they have a muscle problem.”

With the use of a specialized motion capture system, ankle sprain patients' movement can be measured and analyzed.
With the use of a specialized motion capture system, ankle sprain patients' movement can be measured and analyzed.

Through the use of sensors attached to research participants, Han and Lee were able to observe problems with the tibialis anterior and peroneus longus, muscles that control the ankle. After an ankle sprain, it can become more difficult for these muscles to be activated; therefore, treatment or rehab therapy of some type is recommended to strengthen these muscles and speed up recovery.

When considering treatment options for ankle sprains that can reduce the chance of CAI development, it is important that a patient focus on exercises and training that can improve strength and coordination. Physiotherapy or surgery are good options for stabilizing ankle joints; but, in order to enhance strength, stabilization, and coordination, neuromuscular training is recommended. By performing specific exercises, neuromuscular training focuses on training muscles and nerves to react and communicate. This approach to therapy has been tried and tested by multiple researchers. However, as Lee reviewed existing research literature, he saw an opportunity to try something new that could enhance neuromuscular training practices.

“One of the limitations in the literature review was that they knew they had to have patients close their eyes in order to improve balance, but if the patient closes their eyes, their movement is very limited,” Lee says.

Not only are the patients’ movements limited when their eyes are closed, but if they are performing exercise movements with their eyes open, they tend to rely on sight instead of allowing the muscles to do the work. Reliance on sight is often used as a means of protection because patients are worried about exacerbating their injury, or whether or not their ankle can support their movement. Therefore, to maximize muscle reliance, Lee has been testing the use of stroboscopic glasses in neuromuscular rehab training.

Stroboscopic glasses, generally used for athletic training, could also enhance CAI treatment.
Stroboscopic glasses, generally used for athletic training, could also enhance CAI treatment.

Stroboscopic glasses were first designed by Nike for sports training to increase coordination and have been used by athletes like Stephen Curry. The glasses look like a large pair of sunglasses, but the specialized lenses disrupt vision through a strobe, flicker effect to improve sensory skills and coordination. Lee hopes that if their data shows movement improvement in patients through the use of the glasses, that they will be able to provide clinicians with an effective tool in ankle sprain treatment.