Ankle-Sprain History and Ankle Coordination in Both Limbs During Running

Context: Ankle sprain alters joint coordination, but its effect on the ankle coordination of the associated noninjured limb during running remains unknown. Objective: 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: A total of 17 individuals with chronic ankle instability (CAI; age = 22.3 ± 2.5 years, height = 168.6 ± 8.7 cm, mass = 74.8 ± 11.9 kg), 17 copers (age = 22.7 ± 2.4 years, height = 171.0 ± 8.1 cm, mass = 73.9 ± 15.0 kg), and 17 controls (age = 21.8 ± 2.8 years, height = 168.2 ± 8.5 cm, mass = 66.1 ± 11.5 kg). Main Outcome Measuress: Participants ran at 2.68 m/s while 3-dimensional kinematics were collected. A vector coding technique was used to measure coupling of frontal-plane ankle motion (FAK)/transverse-plane tibial motion (TT) and sagittal-plane ankle motion (SAK)/TT in both limbs. A curve analysis was performed to compare coupling angles between limbs within groups and between groups using the noninjured limb in the CAI and coper groups and the right limb in the control group. Results: No differences in coupling were found between the injured and noninjured limbs in the coper and the CAI groups or the right and left limbs in the control group. Overall, the control group had larger SAK/TT coupling angles than the CAI group, but no differences in SAK/TT coupling angles were found between the coper group and the CAI or the control group. The control group had larger FAK/TT coupling angles than the coper group, but no differences in FAK/TT coupling angles were observed between the CAI group and the coper or the control group. Conclusions: All groups demonstrated that both limbs within individuals display the same patterns of ankle-joint coupling. This finding implies that adaptation of interlimb ankle coordination restored symmetry throughout the entire gait cycle of running after an ankle sprain.