Anterior cruciate ligament reconstruction (ACLR) has been considered one of the common treatments for ACL injury. Decrease in the proprioceptive function following ACLR, which may remain between 2 and 3 years after the surgery, provides the possibility of re-injury. Therefore, this study aims to investigate the postural control, weight distribution, and center of pressure (COP) Symmetry Index in individuals with ACLR during quiet standing, in open and closed eyes conditions, compared to healthy people. In the present study, 12 men with right ACLR and 12 healthy men were recruited as participants. Participants stood barefoot on the two force plates. Each foot was placed on one of the 2 platforms. Postural control was assessed during quiet standing in two conditions (open and closed eyes conditions). The positions of COP in antero-posterior and medio-lateral directions are detected under the right and left foot separately and also as net. Postural sway quantified based on five parameters included the amplitude (AMP), total excursions (TOTEX), mean velocity (MVELO), standard deviation (SD), and 95% confidence ellipse area (AREACE). Weight distribution percentage on the lower limbs and COP Symmetry Index in antero-posterior direction were also calculated. The results showed that the COP parameters in some investigated parameters (TOTEXap, SDap, AREACE, AMPap, TOTEXml) were higher in individuals with ACLR than in the healthy group (P<0.05). There was no difference between the two groups regarding the Symmetry Index in the eyes open and closed conditions (P>0.05). Weight distribution, in eyes open condition, in ACLR group on the operated limb is more than that in healthy people (P<0.05).We concluded that individuals with ACLR has a poor postural control in anteroposterior (AP) and mediolateral (ML) directions during quiet standing. The Symmetry Index was the same in both groups. In contrast to the able-bodied participants, individuals with ACLR bear more body weight on the operated limb than on the non- operated limb.
