Measuring Ankle Instability in Pediatric Charcot-Marie-Tooth Disease.

Children with Charcot-Marie-Tooth disease frequently suffer ankle sprain and experience chronic ankle instability; however, no pediatric self-reported measures of chronic ankle instability exist. The aim was to modify and validate the most reliable measure of chronic ankle instability in adults: the Cumberland Ankle Instability Tool. The Cumberland Ankle Instability Tool-Youth was tested for reliability, construct validity, and sensitivity to discriminate between 104 children aged 8 to 16 years: 31 children with Charcot-Marie-Tooth disease, 31 unaffected children with a history of ankle sprains, and 42 controls. Children with Charcot-Marie-Tooth disease had lower scores compared to unaffected children with a history of sprains (χ2 = 15.10; P < .001) and controls (χ2 = 33.69; P < .001). Scores moderately correlated to visual analog scale scores of ankle steadiness (r s = 0.684; P < .001), and "good" test-retest reliability was identified (ICC2,1 = 0.73). The Cumberland Ankle Instability Tool-Youth demonstrated excellent sensitivity and construct validity, identifying chronic ankle instability as a common problem for children with Charcot-Marie-Tooth disease.