Abstract: BACKGROUND: Pro-kin balance system guidance has a relatively excellent rehabilitation effect on lower extremity proprioception and trunk control in stroke patients, but its effect on knee proprioception and balance function in patients after anterior cruciate ligament reconstruction has been less reported.
OBJECTIVE: To investigate the effect of rehabilitation training guided by Pro-kin balance system on proprioception and balance function of the affected knee after anterior cruciate ligament reconstruction. 
METHODS: A total of 84 patients who underwent anterior cruciate ligament rupture reconstruction surgery were randomly divided into observation group and control group, with 42 patients in each group. The patients in the control group received routine rehabilitation intervention after surgery, and those in the observation group were given rehabilitation training based on the guidance of Pro-kin balance system. The training in each group lasted for 8 weeks. Lysholm score and International Knee Documentation Committee score were used to evaluate the change of knee joint function before and after the intervention. Average weight-bearing strength difference, trajectory error, swing value and 30°, 45° and 60° passive angulation errors of the affected knee joint were used to evaluate the changes in the proprioception of the affected knee. The area and length of motion trajectory under open and closed eyes were used to evaluate the change of balance function. The satisfaction of patients in both groups with this rehabilitation training was investigated. 
RESULTS AND CONCLUSION: After training, Lysholm score and International Knee Documentation Committee score of patients in both groups were significantly higher than those before training (P < 0.01), and the above scores in the observation group were significantly higher than those in the control group (P < 0.01). After training, the average weight-bearing strength difference, trajectory error and swing value of the two groups were significantly lower than those before training (P < 0.01), and the above scores in the observation group were significantly lower than those in the control group (P < 0.01). After training, the passive angulation errors of 30°, 45° and 60° of the affected knee joints in both groups were significantly lower than those before training (P < 0.01), and those in the observation group were significantly lower than those in the control group (P < 0.05, P < 0.01). After training, the area and length of motion trajectory in both groups with eyes open were significantly smaller than those before training (P < 0.01), and the above indicators in the observation group were significantly smaller than those in the control group (P < 0.05, P < 0.01). After training, the area and length of the movement track of the patients in both groups with eyes closed were significantly smaller than those before training (P < 0.01), and the above indicators in the observation group were significantly smaller than those in the control group (P < 0.01). The satisfaction of patients in the observation group was 95, which was significantly higher than 81% in the control group (P < 0.05). To conclude, compared with the conventional rehabilitation training, the rehabilitation training based on Pro-kin balance system is more effective in improving the function, proprioception and balance function of the affected knee joints of patients undergoing anterior cruciate ligament rupture reconstruction, and the patients’ satisfaction is higher.

Key words: anterior cruciate ligament rupture, Pro-kin balance system, postoperative rehabilitation, proprioception, balance function