This study will be carried out at Istanbul University-Cerrahpaşa Department of Physiotherapy and Rehabilitation with 30 participants. Subjects who meet the inclusion criteria and who voluntarily agree to participate in this study will be randomly divided into 3 study groups as conventional physiotherapy rehabilitation treatment program, Conventional + virtual reality (VR) group and Conventional + VR+ motor imagery (MI) group. Group 1 (Conventional physiotherapy program): Physiotherapy and rehabilitation treatment program will be applied to the patients. In this program, a 30-40-minute exercise protocol covering proprioceptive, balance and strengthening exercises will be implemented. Group 2; VR group: in addition to the conventional physiotherapy program virtual reality (VR) program will be applied to this group using balance and strengthening games by Nintendo Wii Fit Plus; warm-up exercise (5 minutes), workout (20 minutes) and cool-down exercise (5 minutes) for a total of 30 minutes. Group 3; Motor imagery (MI): this group will be introduced to explicit Motor imagery program adding to Conventional physiotherapy and VR programs. The content of the imagery program will last 20 minutes in total, with 5 minutes of relaxation and 15 minutes of imagery training.

All patients in the groups will be treated for a total of 12 sessions, 3 days a week, over a 4-week period. Session duration will vary according to the groups. Interventions will last approximately 40-80 minutes.

Ankle mobility and instability will be assessed through different tests. Balance parameters will be measured with the Star Balance Test for dynamic balance and the Single Leg Stance Test for static balance. The pain intensity will be measured with the Pressure Pain Threshold device also with Visual Analog Scale. Muscle strength will be assessed with a manual muscle test. Ankle range of motion and joint position feeling will be measured with a mobile application such as an inclinometer. Finally, 2 questionnaires will be used to assess functional ability and patient satisfaction. These are; Cumberland ankle instability tool and Global Assessment Scale questionnaire respectively. All of the assessment parameters (outcomes measurement) will be evaluated twice, pre-treatment and post-treatment (after 4 weeks).Which approximately will take from 30 to 45 minutes.

G\*Power analysis program was used to calculate the sample size of the study. While the Cumberland ankle instability tool (CAIT) change results were taken as reference, the effect size was calculated as 1.35, and the number of subjects to be included in the study was reported as a total of 15 patients (Group 1: 5/Group 2: 5/Group 3: 5) in order to be determined as significant with 95% power and type 1 error=0.05,however, the exclusion rate was added as 25% and it has been decided to include a total of 30 patients (Group 1: 10/Group 2: 10/Group 3: 10) (1). SPSS (Statistical Package for Social Sciences) (SPSS 20.0) statistical program will be used for statistical analysis of the data obtained. In all analyzes, p\<0.05 will be considered statistically significant. Before the final analysis, the data will be screened to test the normality assumption using the Shapiro-Wilk test, which reflects normal distribution (p \> 0.05). Furthermore, Levene's test was used to test homogeneity of variance and no significant difference was found (p \> 0.05). If the data are normally distributed, parametric analysis (e.g. t-Test, ANOVA, Paired t-Test and Linear Regression) will be used, otherwise non-parametric analysis (e.g. Mann-Whitney U Test, Wilcoxon Signed-Rank Test, Kruskal-Wallis Test and Spearman's Rank Correlation) will be used.