Influence of Anterior Cruciate Ligament Reconstruction on Dynamic Postural Control

Abstract

Background: Athletes that have had anterior cruciate ligament (ACL) reconstruction are at a greater risk for reinjury. The relationship between ACL reconstruction and the dynamic postural sway index (DPSI) has not yet been examined. Hypothesis/Purpose:The purpose of this study was to examine the DPSI in a surgically reconstructed ACL limb compared to the uninjured leg in athletes that had been cleared for sport. It was hypothesized that in a bilateral limb comparison, the leg that underwent ACL reconstruction would demonstrate poorer postural stability measures (greater DPSI) during a single leg landing activity as compared to the non-surgical limb.Design: Case-control study.Methods: 14 subjects (7 male, 7 female; age range 16-23 years) with a history of unilateral ACL reconstruction and clearance for return to sport (mean 14 months post-operatively, range 8 to 24 months) performed five single leg hops over a 12 inch hurdle in the anterior direction from a distance corresponding with 40% of their height, onto a force platform. DPSI for the medial-lateral, anterior-posterior, vertical directions and a composite score were calculated for each trial on the surgical and non-surgical legs. A multivariate analysis with repeated measures was used to compare surgical and non-surgical legs for the total DPSI measure as well as for each component.Results: Significant differences (p < .05) in dynamic postural stability were observed in the medial-lateral, anterior-posterior, vertical indices and DPSI total between the surgical and non-surgical limb. Conclusion:Deficits in dynamic postural control persist in ACL-reconstructed limbs compared to the non-surgical limb after the clearance for full activity. Clinicians should consider assessing single limb dynamic stability prior to releasing the athlete back to full activity.

Validity of the frame subtraction method in dynamic postural stability

“…Since all objects in motion were identified by this method, it is necessary to establish an imaging range with only the subject as the object in motion. Second, although jump landing is a common balance task in the clinical and sports fields [9][10][11], it has not yet been investigated whether the frame subtraction method is applicable to more dynamic balance tasks, such as cutting and turning, star excursion balance tasks, and single-limb squats commonly applied to patients with ACL and chronic ankle instability [29][30][31][32]. Therefore, further studies are required.…”

“…The force plate data were sampled at a frequency of 1000 Hz [ 8 ] and passed through a zero-lag fourth-order low-pass Butterworth filter with a 20-Hz cutoff frequency [ 19 ]. Initial contact was defined as the instant the vertical GRF exceeded 10 N [ 11 , 20 ], and the analysis interval was 3 s immediately after landing [ 8 ]. Then the DPSI, MLSI, APSI, and VSI were calculated using the formulas below [ 8 ]: …”

“…Patients with functional ankle instability had less postural stability during single-leg jump landing than in healthy subjects [ 9 , 10 ]. Similarly, significant differences in dynamic postural stability during single-leg jump landing were observed between the injured and non-injured limbs of subjects who underwent unilateral anterior cruciate ligament (ACL) reconstruction [ 11 ]. Moreover, poor dynamic balance is a risk factor for knee and ankle ligament injuries [ 12 , 13 ].…”

“…The DPSI is therefore a highly reliable and precise measure of dynamic postural stability [ 8 ]. In a previous study [ 11 ] targeted patients with ACL reconstruction, significant differences in dynamic postural stability were observed in the MLSI, APSI, VSI, and DPSI in jump landing between the surgical and non-surgical limbs. Additionally, an increased in APSI, VSI, and DPSI in jump landing was reported in patients with chronic ankle instability compared with those in healthy subjects [ 7 ].…”

Additional anterolateral ligament reconstruction helps patients improve dynamic postural stability in revision anterior cruciate ligament reconstruction

“…The ultimate goal of ACLR, whether it is a primary or revision case, is to return to the level of sports activity prior to the injury 15 . To achieve this goal, regaining dynamic postural stability of the affected limb, thus improving asymmetrical control in single-leg balance has been reported to be important 16,17 .…”