Functional Resistance Training After Anterior Cruciate Ligament Reconstruction Improves Knee Angle and Moment Symmetry During Gait: A Randomized Controlled Clinical Trial

PURPOSE: The purpose of this study was to determine 1) whether progressive functional resistance training (FRT) during walking would improve knee biomechanical symmetry after anterior cruciate ligament (ACL) reconstruction and 2) whether the mode of delivery of FRT would have a differential effect on symmetry. METHODS: Thirty individuals who underwent primary ACL reconstruction at a single institution volunteered for this study. Participants were randomized into one of three groups: 1) BRACE, 2) BAND, or 3) CONTROL. The BRACE group received FRT with a novel robotic knee brace along with real-time kinematic feedback. The BAND group received FRT with a custom resistance band device along with real-time kinematic feedback. The CONTROL group received only real-time kinematic feedback. Participants in all groups received training (2-3/week for 8 weeks) while walking on a treadmill. Knee angle and moment symmetry were calculated immediately prior to beginning the intervention and within 1 week of completing the intervention. Statistical Parametric Mapping was used to assess differences in biomechanical symmetry between groups across time. RESULTS: There was a significant interaction in knee moment symmetry from 21 and 24% of the stance phase (P = .046), in which the BAND group had greater improvements following training compared with both BRACE (P = .043) and CONTROL groups (P = .002). There was also a significant time effect in knee angle symmetry from 68 to 79% of the stance phase (P = .028) and from 97 to 100% of the swing phase (P = .050) in which only the BRACE group showed significant improvements after the intervention (stance: P = .020 and swing: P < .001). CONCLUSION: The results of this randomized controlled clinical trial indicate that 8 weeks of progressive FRT during treadmill walking in individuals with ACL reconstruction improves knee angle and moment symmetry during gait. The findings suggest that FRT could serve as a potential therapeutic adjuvant to traditional rehabilitation after ACL reconstruction and can help restore knee joint biomechanical symmetry. LEVEL OF EVIDENCE: Level II, randomized controlled trial.