Effects of Chronic Ankle Instability on Coordination and Coordination Variability of the Lower Limbs Joints During Running

This study aimed to investigate the effect of chronic ankle instability on coordination and variability of coordination of lower limb joints during running. 20 active male subjects (10 subjects with chronic ankle sprain and 10 healthy subjects) started running on the treadmill with connected sensors at a gradual speed. Information about the coordination and variability of 10 steps of each subject in the joints of the lower limbs was extracted in the sagittal plane of all three joints (hip, knee, and ankle) as well as the transverse plane of the ankle. Finally, an independent t-test was used to analyze the statistical analysis at a significant level of (P <0.05). The results showed that coordination at the initiation of the stance phase was significantly lower in the group with chronic ankle sprain than in the healthy group. The coordination of the hip-knee, hip-to-ankle, and knee-to-ankle joints are more different in injured people than in healthy people at the initiation of the stance phase running, so the coordination of these joints is reduced in the sagittal plane of subjects with chronic ankle sprain. Also, the coordination of the knee joints to the ankle in the frontal plane of the injured group is greater than the healthy group. Chronic ankle sprain injury has caused this difference in the pattern of coordination during the stance phase of running, so that the central nervous system of the body, under the influence of fear of re-injury, designs the movement of the ankle joints relative to the knee to minimize the risk of injury.