The Role of Ankle Strength in Functional Ankle Instability
The purpose of this study was to determine if there were any differences in ankle range of motion, strength, or work between persons with normal ankles (Normal,n= 14), those with functional ankle instability (FAI,n= 15), and those with a history of FAI who have been through formal proprioceptive rehabilitation (Rehab,n= 14). A second puipose was to determine normative values for ankle strength and work measurements using the Biodex® isokinetic system. There were no significant differences between groups for ankle range of motion or for any strength or work measurements. The overall strength/work averages were 11.75/3.42 for plantar flexion, 339/1.48 for dorsiflexion, 3.30/2.40 for inversion, and 2.62/1.79 for eversion. Dorsiflexion torque overall was 31.43% of plantar flexion, and the evertors produced 75.42% of the torque produced by the invertors. It is recommended that clinicians continue to rehabilitate ankles with strength and proprioceptive exercises but do not rely on ankle strength/work testing as the only criteria for determining an athlete's readiness to return to full activity.