Time-Dependent Alterations in Walking Biomechanics After Anterior Cruciate Ligament Reconstruction Compared with Healthy Individuals: A Systematic Review with Meta-analysis

Abstract Background Knee injuries involving the anterior cruciate ligament (ACL) are often treated through surgical care to restore knee joint stability. Despite surgical treatment, there is evidence of altered biomechanical gait characteristics for short-, mid-, and even long-term post ACL reconstruction (ACLR). Objective In this systematic review with meta-analysis, we aimed to analyze lower extremity joint kinematics and kinetics recorded during walking in individuals with ACLR and determine the time course of recovery of gait biomechanics following ACLR. Methods Five electronic databases (Scopus, PubMed, EMBASE, Physiotherapy Evidence Database (PEDro), Cochrane Central Register of Controlled Trials [CENTRAL]) were systematically searched for articles potentially eligible for inclusion from inception until January 2026. A PECOS (Participants: ACLR individuals aged ≥ 18; Exposure: ACL surgery; Comparators: healthy controls; Outcomes: lower limb kinematics and kinetics during the walking stance phase; and Study design: case control studies, case series, cross-sectional studies, randomized controlled trials [baseline], cohort studies) approach was applied to define inclusion and exclusion criteria. Using cross-sectional studies, gait biomechanics were assessed short- (0–