Article Text
Abstract
Background Despite recent advances in rehabilitation and secondary prevention strategies after anterior cruciate ligament reconstruction (ACLR), re-injury rates remain high and long-term outcomes are often disappointing. Deficits in postural stability are shown to be important.
Objective To evaluate postural stability during the transition from double-leg stance to single-leg stance in ACLR and non-injured control subjects.
Design Cross-sectional (retrospective).
Setting Controlled laboratory study.
Participants 20 ACLR subjects (15 females, 5 males), 23.1±13.9 months after ACLR and fully returned to their pre-injury sport, and 20 non-injured control subjects (15 females, 5 males) participated in the study. Both groups were matched for age, gender, weight, height and activity level. All ACL injuries were caused by a non-contact injury mechanism.
Risk factor assessment A transition task from double-leg stance to single-leg stance with eyes closed was performed while standing on a single force plate. Movement speed was standardized. Both legs of each subject were tested.
Main outcome measurements Spatiotemporal center of pressure outcomes were compared between groups and between legs within the same group. Significance was set at P<.05.
Results The ACLR group showed a significant increased postural sway after the new stability point during single-leg stance (P=.005). No significant different postural stability outcomes were found between legs in both groups (P>.05).
Conclusions Despite the full return to sport, ACLR subjects showed a decreased ability to overcome the postural perturbation created by the transitional movement. These postural stability deficits may leave the lower extremity more vulnerable to ACL re-injury and/or other long-term problems after ACLR. Whether these deficits are a result or a pre-existing risk factor of the initial ACL injury remains unclear. The lack of bilateral differences in the ACLR group may imply that secondary prevention strategies should not only focus on the ACLR leg, but also on the non-ACLR leg.