Dynamic Single-Leg Postural Control Is Impaired Bilaterally Following Anterior Cruciate Ligament Reconstruction: Implications for Reinjury Risk.

Adam G Culvenor, Bryce C Alexander, Ross A Clark, Natalie J Collins, Eva Ageberg, Hayden G Morris, Timothy S Whitehead, Kay M Crossley

Study Design Controlled laboratory study; cross-sectional. Background Postural control following anterior cruciate ligament reconstruction (ACLR) primarily has been investigated during static single-leg balance tasks. Little is known about dynamic postural control deficits post-ACLR. Objectives To compare dynamic postural control (bilaterally) in persons who have undergone ACLR and healthy controls, and to evaluate the relationship between dynamic postural control and self-reported and objective function. Methods 97 participants (66 males, median age 28 years) 12 months post-ACLR and 48 healthy controls (20 males, median age 30 years) underwent balance assessment using a Nintendo Wii Balance Board during a single-leg squat. Center of pressure (CoP) path velocity, as well as CoP amplitude and standard deviation (SD) in both mediolateral (ML) and anteroposterior (AP) directions, were recorded. Self-reported function was assessed with the International Knee Documentation Committee Subjective form (IKDC), while hop-for-distance was used to evaluate functional status. Results Compared to healthy controls, the ACLR group had greater mean CoP path velocity (16% higher, p=0.004), ML range (23%, p<0.001), ML SD (28%, p<0.001), AP range (14%, p=0.009) and AP SD (15%, p=0.013) indicating worse dynamic balance post-ACLR. Dynamic balance performance was similar between the ACLR limb and the uninjured contralateral limb. AP SD was weakly associated with hop performance (β -0.2, p=0.046); no balance measures were associated with the IKDC score. Conclusion Individuals who have undergone ACLR demonstrate impaired dynamic balance bilaterally when performing a single-leg squat which may have implications for physical function and future injury risk. Routine dynamic balance assessment may help identify patients who could benefit from targeted neuromuscular training programs to improve objective function and potentially lower re-injury risk. J Orthop Sports Phys Ther, Epub 21 Mar 2016. doi:10.2519/jospt.2016.6305.