Influence of virtual reality games(Wii Fit) on knee proprioception after anterior cruciate ligament reconstruction (ACLR) will be measured in 30 postoperative patients. The age of participants will be ranged from 20 to 30 years old. Subjects will be randomly assigned to Group A is the study group and Group B is the control group.

Group A will receive the Wii fit protocol of virtual reality games, in addition to the regular exercise rehabilitation protocol, for 3 non-consecutive days per week, for 8 weeks , 40 minutes for each session. Group B will receive the regular exercise rehabilitation protocol only for 3 non-consecutive days per week for 8 weeks, 40 minutes for each session.

A Universal Weight and Height Scale: will be used to measure the patient's BMI.

Biodex Isokinetic Dynamometer: will be used to assess the knee proprioception of the affected operated leg at three target angles (30,45,and 60 degrees).

Inclusion Criteria:

1. patients who will be in the early postoperative phase (week 2 after surgery)
2. patients with BMI less than 25, and more than 20.

Exclusion Criteria:

1. Patients with injury or operation accompanied by the ACLR as meniscectomy.
2. Patients with any deformities affecting knee joint alignment as genu valgus, genu varus, or genu recurvatum.