Altered postural sway persists after anterior cruciate ligament reconstruction and return to sport

Abstract

Postural sway is defined as the movement of a body's center of mass within the base of support to maintain postural equilibrium. Deficits in postural sway are present after ACL injury; however, current evidence linking it to future injury risk is unclear. The purpose of this study was to determine if postural sway deficits persist after ACL reconstruction (ACLR). The hypothesis tested was that after ACLR, patients who return to sport (RTS) would demonstrate differences in postural sway compared to control (CTRL) subjects. Fifty-six subjects with unilateral ACLR released to RTS, and 42 uninjured CTRL subjects participated. Dynamic postural sway was assessed and 3-way (2×2×2) ANOVA was used to analyze the variables. A side×group×sex (p=0.044) interaction in postural sway was observed. A side×group analysis also revealed an interaction (p=0.04) however, no effect of sex was observed (p=0.23). Analysis within the ACLR cohort showed less (p=0.001) postural sway on the involved side (1.82±0.84°) versus the uninvolved side (2.07±0.96°). No side-to-side differences (p=0.73) were observed in the CTRL group. The involved limb of subjects after ACLR demonstrated the least postural sway. In conclusion, these findings indicate that dynamic postural sway may be significantly altered in a population of athletes after ACLR and RTS compared to CTRL subjects. Further investigation is needed to determine if deficits in postural sway can be used as an effective criterion to assist in the decision to safely RTS after ACLR.

Figure 1

Demonstration of postural sway assessment

Figure 2

Examples of postural control tracing representative of ranges of postural stability and postural sway.

Figure 3

Postural sway (ACLR vs. Control) during a single limb stance on an unstable platform. (Blue=involved/non-preferred limb; Green=uninvolved/preferred limb) (* = p<0.05)