Postural stability impairments in non-athletic individuals after anterior cruciate ligament reconstruction: a cross-sectional study

TL;DR

Non-athletic individuals who had ACL surgery showed lasting postural stability issues, especially in dynamic tasks, even a year after surgery.

Contribution

This study identifies persistent postural deficits in non-athletic ACLR patients using both static and dynamic stability assessments.

Findings

ACLR patients showed greater COP sway in bipodal stance compared to controls.

Operated limbs had lower Y-Balance Test scores compared to control group's non-dominant limb.

Postural deficits persisted in dynamic tasks despite limb symmetry in static tests.

Abstract

Anterior cruciate ligament (ACL) injuries are common knee injuries that impair postural stability due to the loss of mechanoreceptors, affecting proprioceptive feedback and sensorimotor control. The aim of our study was to comprehensively investigate the postural stability in non-athletic individuals who had undergone ACL reconstruction (ACLR) and exploring their relationship with patient-reported outcomes.

A total of 58 participants were included in the study, consisting of 29 individuals who underwent ACLR and 29 control group participants matched for age, height, weight, and sex. Static stability (bipodal and single-leg) was assessed using a force plate by evaluating center of pressure (COP) parameters, while dynamic stability was measured with the Y-Balance Test. During tests, the operated limb in the ACL group was compared with the non-dominant lower extremity of the control group. Group comparisons were performed using independent sample t-tests and Mann–Whitney U tests, and within-group analyses were conducted using paired sample t-tests or Wilcoxon tests. Spearman correlation analysis was used, and statistical significance was set at p < 0.05.

When comparing bipodal stance scores between the groups, the ACL group exhibited greater anteroposterior amplitude of the COP sway (p < 0.001). No differences were observed between the operated and non-operated limbs in single-leg stance parameters (p > 0.05); however, when compared with the control group’s non-dominant limb, the control values were better than the operated limb (p < 0.05). In the Y-Balance Test, anterior reach and composite scores were significantly lower on the operated limb (p < 0.05). When compared with the control group, the ACL group demonstrated lower performance in anterior, posterolateral and posteromedial reaches, as well as composite scores (p < 0.05). No clinically relevant limb-symmetry deficits were observed within the ACL group (p > 0.05).

In non-athletic individuals, limb symmetry was achieved in static postural stability tests post-operatively; however, differences compared to healthy individuals persisted. Postural deficits were more pronounced particularly in single-leg stance and dynamic postural stability tasks. These findings suggest that postural stability deficits in non-athletic populations may persist at least 12 months post-surgery.

NCT07210853 retrospectively registered. ( date29/09/2025).