Hamstring extensibility and transverse plane knee control relationship in athletic women

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedics

Background:

• Athletic women face a high risk of non-contact anterior cruciate ligament (ACL) injuries.
• Hamstrings play a crucial role in dynamic knee motion control, particularly in the sagittal and transverse planes during running.
• Reduced hamstring extensibility has been hypothesized to enhance knee motion control.

Purpose of the Study:

• To investigate the correlation between hamstring extensibility and transverse plane knee kinematics in athletic women.
• To describe the dynamic transverse plane knee motion control capabilities of the hamstrings based on extensibility.

Main Methods:

• Twenty healthy athletic women underwent crossover-cut training.
• Active hamstring extensibility and 3D knee/ankle kinematics were measured using retroreflective markers and motion capture.
• Pearson correlations were calculated between hamstring extensibility and kinematic variables, with statistical significance set at P < 0.05.

Main Results:

• Hamstring extensibility showed significant positive correlations with tibial external rotation at heelstrike (r = 0.62, P = 0.004).
• Increased hamstring extensibility was associated with decreased tibial internal rotation at peak knee flexion (r = 0.47, P = 0.01).
• Greater hamstring extensibility led to increased tibial external rotation at heelstrike and reduced tibial internal rotation during peak flexion.

Conclusions:

• Increased hamstring extensibility may enhance knee extensor efficiency at heelstrike via greater tibial external rotation.
• Improved hamstring extensibility may protect the ACL at peak knee flexion by reducing tibial internal rotation.
• Hamstring extensibility is a significant factor in controlling transverse plane knee motion during athletic activities.