Measures of functional limitation as predictors of disablement in athletes with acute ankle sprains

Prospective multivariate design. To determine the usefulness of activity scores, self-reported athletic ability, and selected measures of physical impairment as predictors of disability duration in athletes with ankle inversion sprains. Although several measures of physical impairment and functional limitation are used to assess the consequences of injury following ankle sprain, researchers have yet to establish which measures provide the most accurate predictions of disability duration. Physical impairment, activity limitation, and disability duration were measured in 21 athletes (13 men and 8 women; mean age = 20.3 +/- 1.7 years) with acute ankle sprains. Sagittal plane ankle range of motion and volumetric displacement were used as impairment indicators. Weight-bearing activity scores (task completion count) and self-reported athletic ability (visual analog scale) were used to represent functional limitation. Elapsed time from injury to return to full athletic participation was used as the criterion measure of disability duration. The impairment measures accounted for approximately one-third of the variance in disability duration (R2 = 0.342). Adding the activity limitation measures to the regression model improved predictions of disability duration (R2 = 0.670; stepwise R2 change = 0.328). The measures of activity limitation alone, however, accounted for approximately 67% (R2 = 0.665) of the total variance in the number of days lost due to injury. Measures of activity limitation were the strongest predictors of elapsed time from injury to return to full athletic participation.