An Updated Model of Chronic Ankle Instability

Abstract

Lateral ankle sprains (LASs) are among the most common injuries incurred during participation in sport and physical activity, and it is estimated that up to 40% of individuals who experience a first-time LAS will develop chronic ankle instability (CAI). Chronic ankle instability is characterized by a patient's being more than 12 months removed from the initial LAS and exhibiting a propensity for recurrent ankle sprains, frequent episodes or perceptions of the ankle giving way, and persistent symptoms such as pain, swelling, limited motion, weakness, and diminished self-reported function. We present an updated model of CAI that aims to synthesize the current understanding of its causes and serves as a framework for the clinical assessment and rehabilitation of patients with LASs or CAI. Our goal was to describe how primary injury to the lateral ankle ligaments from an acute LAS may lead to a collection of interrelated pathomechanical, sensory-perceptual, and motor-behavioral impairments that influence a patient's clinical outcome. With an underpinning of the biopsychosocial model, the concepts of self-organization and perception-action cycles derived from dynamic systems theory and a patient-specific neurosignature, stemming from the Melzack neuromatrix of pain theory, are used to describe these interrelationships.

Keywords: ankle sprains; anterior talofibular ligament; calcaneofibular ligament; diagnosis; rehabilitation.

Figure 1

The updated model of chronic ankle instability (CAI). The outcome is determined at least 12 months after the initial ankle sprain. Abbreviations: ATFL, anterior talofibular ligament; CFL, calcaneofibular ligament; HRQOL, health-related quality of life.

Figure 2

Adaptation of the model to illustrate the specific impairments of a 15-year-old female high school basketball player who has chronic ankle instability (CAI). The enlarged circles and text indicate specific impairments that are contributing to her condition and health status. Abbreviations: AT, athletic trainer; BMI, body mass index; HRQOL, health-related quality of life.

Figure 3

Adaptation of the model to illustrate the specific impairments of a 35-year-old male construction worker who has chronic ankle instability (CAI). The enlarged circles and text indicate specific impairments that are contributing to his condition and health status. Abbreviations: BMI, body mass index; HRQOL, health-related quality of life.

Figure 4

Adaptation of the model to illustrate the specific impairments of a 22-year-old graduating female collegiate athlete who has a history of ankle sprains and has changed her level of physical activity to cope with her ankle injury. The enlarged circles and text indicate specific impairments that are contributing to her condition and health status. Abbreviations: ACL, anterior cruciate ligament; HRQOL, health-related quality of life.