Gait differences after ACL reconstruction versus healthy controls: a three-level meta-analysis of kinematics, kinetics, and spatiotemporal parameters.

OBJECTIVES

This meta-analysis was designed to evaluate whether individuals following ACL reconstruction exhibit normalized gait biomechanics when compared to healthy controls.

METHODS

This review was conducted across five databases: PubMed, Embase, The Cochrane Library, Web of Science and EBSCOhost-SportDiscus, yielding a total of 5,251 records, with 21 qualified studies (52 independent samples from 861 participants; based on available data, the mean age was 26.5 ± 4.3 years and 51.3% were female) eligible for quantitative synthesis following rigorous screening. A three-level meta-analysis model was implemented to address effect size dependencies. Six gait parameters were analyzed, including kinematic variables (peak knee flexion and extension angles during stance), kinetic variables (peak external knee flexion and extension moments during stance) and spatiotemporal variables (stride length and walking speed).

RESULTS

Among the six gait parameters that were analyzed, only the peak knee extension angle during stance (k = 9, d = 0.83, 95% CI: 0.26-1.40, I2 = 77.53%, p = 0.01) showed a significant difference between ACL reconstruction patients and healthy controls. However, peak knee flexion angle, peak external knee flexion and extension moments during stance, stride length and walking speed were not significantly different between groups (p > 0.05). Meta-regression identified a significant time-dependent improvement only for knee extension angle (F = 5.656, p = 0.049), while postoperative duration had no significant effect on other outcomes.

CONCLUSION

This meta-analysis shows that the majority of gait parameters during stance, including peak knee flexion angle, external knee flexion and extension moments, stride length and walking speed, do not differ significantly between individuals with ACL reconstruction and healthy controls. Only peak knee extension angle remained impaired, though it showed signs of improvement over time. Persistent knee extension deficits emphasize the need for targeted quadriceps and knee control training as a key focus for long-term ACLR rehabilitation.