Biomechanical deficiencies in women with semitendinosus-gracilis anterior cruciate ligament reconstruction during drop jumps

Academic Article


  • Objective: To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and noninjured women during double- and single-legged drop jumps. Design: Cross-sectional biomechanical study. Setting: Single university-based biomechanics laboratory. Participants: Fourteen women 1-5 years post-SG-ACLr and 16 noninjured women participated in this study. Methods: After anthropometric measurements, warm-up, and familiarization procedures, participants performed 5 trials of a double- and single-legged drop jumps. Main Outcome Measurements: Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jump tasks, neuromuscular recruitment was evaluated through rectified normalized electromyographic activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings electromyographic co-contraction ratio. Results: Although the SG-ACLr group demonstrated a tendency toward a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group, depending on the specific jump. Conclusions: These findings suggest that women with SG-ACLr have a tendency toward greater dynamic knee valgus that could predispose to additional knee injuries. Rehabilitation specialists need to be aware of existing kinematic and neuromuscular deficiencies years after SG-ACLr. Taking this into consideration will aid in prescribing appropriate interventions designed to prevent re-injury.
  • Digital Object Identifier (doi)

    Author List

  • Ortiz A; Capo-Lugo CE; Venegas-Rios HL
  • Start Page

  • 1097
  • End Page

  • 1106
  • Volume

  • 6
  • Issue

  • 12