Chronic Ankle Instability

What is Chronic Ankle Instability?

Chronic ankle instability can be broken down into two categories: Mechanical instability and Functional instability. Mechanical instability is when there is a laxity in the ligaments of your ankle joint and you have a history of previous ankle sprains. Functional instability is when you feel that your ankle is unstable or that it is “giving way” without any other physical symptoms such as pain.

How does Chronic Ankle Instability happen?

This usually arises from repeated ankle sprains where the ligaments do not heal properly or completely. The most common mechanism of injury (~80%) involves a forceful inversion (foot turning in) and plantarflexion (extension of the ankle) motion of the foot and ankle. This results in damage to the structures of the lateral (outside) ankle including: the Anterior talofibular ligament (ATFL) and the Calcaneofibular ligament (CFL).

Did you know that up to 20% of lateral ankle sprains can lead to chronic ankle instability?

How can I treat chronic ankle instability?

You can treat ankle sprains and instability with a variety of conservative methods including:

  • Rest
  • Ice
  • Bracing
    • For protection and stability during weight bearing
  • Taping
  • Orthotics
  • Physical Therapy
    • To work on:
      • Muscle strength and endurance
      • Ankle range of motion
      • Balance (proprioception) training

If conservative methods fail, due to increased damage to the ligaments resulting in a high level of instability, surgery may be an alternative an option. Consult with your PT and MD to discuss the best option for you!


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  2. Waterman et al. The epidemiology of ankle sprains in the United States. J Bone Joint Surg Am. 2010; 92-A(13):2279-2284.
  3. Li et al. Treatment of chronic lateral ankle instability: A modified brostrom technique using three suture anchors. Journal of Orthopaedic Surgery and Research. 2009; 4 (41). DOI: 10.1186/1749-799X-4-41
  4. Wainright et al. The Effect of Modified Brostrom-Gould Repair for Lateral Ankle Instability on in Vivo Tibiotalar Kinematics. Am J Sports Med. 2012; 40(9): 2099-2104.
  5. Sherry, M. Rehabilitation guidelines for Lateral Ankle reconstruction. University of Wisconsin Sports Medicine. 2014.