1. Introduction
roprioception is the ability to feel or perceive spatial position and body movements without using the eyes. The joint position’s sensory receptors include the muscular spindle’s receptors, the Golgi tendon organ, and the articular receptors, which transmit information about this sense to the central nervous system [1]. These receptors are responsible for creating awareness of the state of motion and coordination of different body parts relative to each other [2]. In other words, proprioception is a broad term for the sensation of movement, which receives sensory input from the receptors of the muscular spindle, tendon, and joints, and determines the position and motion of the joint, and regulates the direction, intensity, and velocity of the joints [3].
It should be noted that knee disorders, such as knock-knees, reduce the knee joint’s proprioception, increasing the possibility of injury and pain [1]. This study aimed to evaluate the effect of proprioception exercises on knee joint reconstruction and alleviation of knee pain in athletes with genu valgum.
2. Materials and Methods
In this quasi-experimental study, 30 female athletes (referred to a medical clinic in Arak city) in the age range of 20-30 years were randomly divided into “experimental” and “control” groups. In the pre-test and post-test, the standard knee pain questionnaire was used to measure the subjects’ pain. Then the joint diagnosis test was used to assess the knee’s proprioception with digital images (by AutoCAD software). In the experimental group, athletes performed proprioception reinforcement exercises for 8 weeks (three sessions per week, 20 minutes per session). The Kolmogorov-Smirnov test and paired t-test were used to check the data normality and analyze it, respectively. Data were calculated using SPSS software v. 16 and a 95 (P≤0.05) confidence level.
3. Results
The results of this study indicated that a period of proprioception exercises reduced joint reconstruction error and knee pain in female athletes with genu valgum (Table 1). 


4. Discussion and Conclusion
This study aimed to investigate the effect of proprioception exercises on knee joint reconstruction and alleviation of knee pain in female athletes with genu valgum. In the functional test of knee condition diagnosis, which was performed to check the knee’s proprioception, the pre-test and post-test information were compared, and the differences were significant. This significance indicated a reduction in angle reconstruction error compared to the pre-test. This information confirms that the training program significantly improves knee proprioception in athletes with knock-knees.
According to the mean in the pre-test and post-test, the results revealed that in the control group, there was no change in the situation of the subjects at the end of the study compared to the beginning. Based on the comparison of the two groups, we concluded that the exercises performed improved knee proprioception in female athletes with painful genu valgum. This study was consistent with the research conducted by Ghaffarinejad (2007), Hakan et al. (2005), and De Bolt (2004) and was not consistent with the study of Larsen et al. (2005) [2, 3, 4, 5].
The cause of knock-knee deformity cannot be definitively limited to one factor. Still, it seems that among athletes, repetitive movements that are performed to a large extent can cause the joint to deviate from the average direction and be inclined to be in a specific position [6]. Being in this particular position is a kind of adaptation to the pressures that put the joint under repetitive force. Of course, it should be noted that genetic factors or the presence of underlying diseases such as osteoporosis can also cause the joint to deviate from its average direction [5]. 
No different results were obtained from what others have already mentioned, but we looked at these exercises’ effect on people with a knock-knee in this study. No research has been done in this field. Simultaneously, as mentioned earlier, in these subjects, we noticed a decrease in proprioception of the knee due to deviation from the average direction [6]. The advantage of our research over other studies was its preventive aspect. 
This study confirmed that proprioception reinforcement exercises could increase the sense of diagnosis in the knee joint. Based on the above explanations, it can be concluded that if performed by athletes with a knock-knee, these exercises can strengthen their proprioception, save them from complications that may occur in the future, or at least reduce the possibility of joint problems in the knee.

Ethical Considerations
Compliance with ethical guidelines
All ethical principles are considered in this article. The participants were informed of the purpose of the research and its implementation stages. They were also assured about the confidentiality of their information and were free to leave the study whenever they wished, and if desired, the research results would be available to them.

Funding
This article is extracted from the MSc. thesis of Mohammad Mirghasemi at the Department of Physical Education and Sport Sciences, Faculty of Humanities, Borujerd Branch, Azad University, Lorestan. 

Authors' contributions
Conceptualization: Mohammad Mirghasemi; Supervisor: Masoud Golpayegani; Methodological assistance: Mohammad Rahim Amiri; Resources and writing – review & editing: Fariba Moradi Vestagani.

Conflicts of interest
The authors declared no conflict of interest.


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