Prospective correlational study involving a convenience sample.To investigate the relationships among figure-of-eight girth measurements and functional level in patients with acute lateral ankle sprains to determine the appropriate use of these clinical measures.Research has shown that subjective scales of perceived athletic ability and measurements of swelling are useful in assessing clinical improvement following an acute ankle sprain; however, the relationship between ankle swelling and level of function is not known.Twenty-nine subjects (20 men, 9 women) varying in age from 18-59 years of age (mean age, 30.8 +/- 11.37) with acute lateral ankle sprains were included in this study. Each subject was evaluated by 1 of 3 raters for ankle girth, weight-bearing status, and functional level as determined by a modified Ankle Osteoarthritis Scale (AOS) and the Foot and Ankle Ability Index (FAAI). This study also investigated the relationship between these measures and the sport subscale of the FAAI (FAAI sport). This is an 8-item subscale which includes questions on running, jumping, landing, quick starts and stops, cutting or lateral movements, low impact activities, ability to perform an activity with normal technique, and ability to participate in desired sports.No significant correlations were found between figure-of-eight girth measurements and functional level. However, we did find moderate to good correlations between the FAAI vs. weight-bearing (rho = 0.73), FAAI vs. AOS (rho = -0.79), FAAI sport vs. weight-bearing (rho = 0.68), FAAI vs. FAAI Sport (rho = 0.73), weight-bearing vs. AOS (rho = -0.57), and FAAI Sport vs. AOS (rho = -0.50).The figure-of-eight method is highly reliable and is appropriate for measuring ankle swelling; however, it does not correlate with functional level as determined by the modified AOS, FAAI, or observed weight-bearing status during gait. Therefore, clinicians should refrain from making assumptions about function based on ankle swelling.
