Abstract: BACKGROUND: Due to proprioceptive deficits, athletes after anterior cruciate ligament reconstruction may use compensatory stabilization strategies to reweight sensation toward more reliable visual stimuli. However, it is unclear how interference with visual information affects lower limb biomechanics.
OBJECTIVE: To investigate the effects of visual interference on the kinematic and dynamic characteristics of lower limbs during single-leg landing in athletes after anterior cruciate ligament reconstruction and healthy athletes.
METHODS: Twenty athletes undergoing anterior cruciate ligament reconstruction and 20 healthy athletes were recruited and randomly subjected to two different visual conditions: eyes open and visual interference. They completed single-leg landing under the two visual conditions. Visual interference was performed using stroboscopic glasses with a frequency of 3 Hz, i.e. 0.1 seconds with eyes open and 0.233 seconds with eyes closed. The kinematic parameters of the affected/dominant lower limbs were collected using an infrared high-speed motion capture system (200 Hz), and the kinetic parameters of the lower limbs were collected using a three-dimensional force platform (1 000 Hz). Two-way repeated measures analysis of variance was used to determine the effects of group and visual condition on kinematic and kinetic variables.
RESULTS AND CONCLUSION: (1) Compared with the eyes-open condition, the knee valgus angle (P=0.026) and ankle varus angle (P=0.006) of athletes undergoing anterior cruciate ligament reconstruction and healthy athletes at the initial landing moment under visual interference conditions significantly increased. (2) Compared with the eyes-open condition, visual interference increased the knee valgus angle at the peak knee flexion moment in athletes after anterior cruciate ligament reconstruction (P < 0.001), but it did not significantly increase the knee valgus angle in healthy athletes (P=0.527). (3) Compared with the eyes-open condition, under visual interference conditions, the hip extension moment of athletes udnergoing anterior cruciate ligament reconstruction and healthy athletes at the peak knee flexion moment was significantly increased (P=0.047), and the knee extension moment was significantly reduced (P=0.001). To conclude, visual interference increases knee valgus and ankle varus angles in athletes undergoing anterior cruciate ligament reconstruction and healthy athletes, which may increase the risks of anterior cruciate ligament injury/secondary injury and lateral ankle sprain. In addition, visual interference causes compensatory strategies of proximal load shift in the sagittal plane in athletes.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: visual interference, stroboscopic glasses, anterior cruciate ligament reconstruction, single-leg landing, kinematics, kinetics, biomechanics, athletes