A history of ankle sprain alters ankle coordination in both limbs during running

Context: Ankle sprain alters joint coordination, but its effect on the ankle coordination of the associated non-injured limbs during running remains unknown. Objective: The present study aimed to investigate the effects of a history of ankle sprain or chronic ankle sprain on the coordination in both involved and uninvolved limbs during running. Design: Cross-sectional study Setting: Laboratory Patients or Other Participants: Seventeen individuals with chronic ankle instability (CAI), 17 copers and 17 controls ran at 2.68 m/s while 3D kinematics were collected. Main Outcome Measure (s): A vector coding technique was used to measure coupling of frontal plane ankle motion/transverse plane tibia motion (FAK/TT) and sagittal plane ankle motion/transverse plane tibia motion (SAK/TT) in both limbs. A curve analysis was performed to compare coupling angles between limbs within groups, and between the uninjured limbs of control and coper groups with the control group. Results: No differences in coupling were found between the injured and non-injured limbs in each group, or left and right limbs in the control group. Overall, controls had greater SAK/TT coupling angles than individuals with CAI, but there were no differences in SAK/TT coupling angles in copers compared to individuals with CAI and controls. Controls had greater FAK/TT coupling angles than copers, but there were no differences in FAK/TT coupling angles in individuals with CAI compared to copers and controls. Conclusions: All groups demonstrated that both limbs within an individual display the same patterns of ankle joint coupling. This finding implies that adaptation of the interlimb ankle coordination restored symmetry throughout the entire gait cycle of running following an ankle sprain