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Clinical Scenario: Knee muscle strength weakness after anterior cruciate ligament (ACL) reconstruction is the most commonly seen impairment. Whole-body vibration (WBV) training has been shown to improve muscle strength in both healthy and injured individuals. However, it is not clear yet if WBV training has a beneficial effect in knee muscle strength recovery after ACL reconstruction. Clinical Question: Is adding WBV training to conventional rehabilitation more effective than conventional rehabilitation at improving quadriceps and hamstring muscles strength in individuals who have undergone ACL reconstruction? Summary of Key Findings: After the literature was reviewed, 4 randomized controlled trials met the inclusion criteria and were included in this critically appraised topic. Clinical Bottom Line: There is moderate- to high-quality evidence to support that adding WBV to conventional rehabilitation programs can result in better improvement in knee muscle strength after ACL reconstruction. Strength of Recommendation: Findings from 4 randomized controlled trials indicate that there is level B evidence supporting that WBV is effective for knee muscle strength recovery in patients who had undergone ACL reconstruction.

Purpose: The aim of this study was to investigate the effects of abdominal bracing maneuver (ABM) on quadriceps peak torque (PT), time to peak torque (TTPT) and activation levels during quadriceps maximal strength testing in healthy individuals. Methods: Sixteen healthy individuals (Age: 24.63±1.67 years) participated in this study. Each participant was thought the ABM technique by a physical therapist. Surface electromyographic was used to measure internal oblique/transversus abdominis, vastus medialis, vastus lateralis and rectus femoris activation levels. Isokinetic dynamometry was used to measure quadriceps PT and TTPT during maximum isometric testing at 60° and 90° of knee flexion angles. Repeated measures of ANOVA was used to statistical analysis. Results: There was a significant angle by condition interaction for quadriceps PT (F(1,15)=5.30, p=0.04). PT values both decreased with ABM, but the decrease was greater at 60 compared to 90 degrees of knee flexion (60°: p=0.001, ES=0.68; 90°: p=0.008, ES=0.33). Quadriceps activation levels also decreased with ABM (p=0.04). Conclusion: The present study reveals that ABM could decrease the muscle activation levels and peak torque during maximal quadriceps strength testing. Investigators should examine the compensatory lumbopelvic movements during maximal quadriceps strength testing to prevent misleading by the force transmission.