Pain and dorsiflexion range of motion predict short- and medium-term activity limitation in people receiving physiotherapy intervention after ankle fracture: an observational study.

QUESTION What predicts short - and medium term activity limitation in people after ankle fracture? DESIGN Inception cohort observational study. PARTICIPANT Adults with ankle fracture recruited within days following cast removal from physiotherapy departments of teaching hospital in Sydney, Australia. OUTCOME MEASURES The predictive value of variables that were injury-related (fracture management, fracture severity, angle of the ankle during cast immobilisation, and time from cast removal to baseline) and performance-related (activity limitation, pain, mobility and dorsiflexion range of motion measured soon after cast removal) were examined in one dataset (n = 150) using univariate linear regression. Significant variables (p <or = 0.20) were further examined with a multivariate linear model. A clinical prediction rule was derived then validated using data from an independent dataset (n = 94). RESULTS Fracture management, fracture severity, baseline activity limitation, pain, mobility and dorsiflexion had significant but weak univariate associations with activity limitation. Only pain and dorsiflexion range of motion contributed independently to the clinical prediction rule. When applied to the validation data, the rule explained 12% of the short-term and 9% of the medium-term variance in activity limitation. CONCLUSION Performance-related variables were stronger predictors than injury-related variables. A clinical prediction rule consisting of pain and dorsiflexion range of motion explained a small amount of variance in short- and medium-term activity limitation, suggesting that it may be appropriate to identify people with high levels of pain and restricted dorsiflexion after ankle fracture and target intervention accordingly.