Active Ankle Circumduction to Identify Mobility Deficits in Subacute Ankle Sprain Patients

Assessment of ankle mobility is complex and of clinical relevance after an ankle sprain. This study develops and tests a biomechanical model to assess active ankle circumduction and its reliability. The model was then applied to compare individuals' ankle mobility between injured and noninjured ankles after a sprain episode. Twenty patients with subacute unilateral ankle sprain were assessed at 4 weeks and 10 weeks after the injury. They underwent a clinical exam and an ankle circumduction test during which the kinematics were recorded with an optoelectronic device. A biomechanical model was applied to explore ankle kinematics. Reliability of the ankle circumduction tests were good to excellent (ICC of 0.55-0.89). Comparison between noninjured and injured ankles showed a mobility deficit of the injured ankle (dorsiflexion = -27.4%, plantar flexion = -25.9%, eversion = -27.2%, and inversion = -11.6%). The model allows a graphical representation of these deficits in 4 quadrants. Active ankle circumduction movement can be reliably assessed with this model. In addition, the graphical representation allows an easy understanding of the mobility deficits which were present in all 4 quadrants in our cohort of patients with subacute ankle sprain.