Quantifying Recovery After Anterior Cruciate Ligament Reconstruction Using the Torque- Velocity Relationship

Area of Science:

• Biomedical Engineering
• Sports Medicine
• Orthopedics

Background:

• Anterior cruciate ligament reconstruction (ACLR) often results in lasting quadriceps strength deficits.
• Traditional strength assessments (isometric, single-velocity isokinetic) fail to capture the full picture of muscle function post-ACLR.
• Accurate characterization of muscle function is crucial for guiding rehabilitation and improving patient outcomes.

Purpose of the Study:

• To demonstrate the utility of multi-velocity isokinetic testing in characterizing the torque-velocity relationship after ACLR.
• To highlight how this method can identify persistent strength deficits missed by conventional assessments.
• To provide a framework for monitoring recovery and informing clinical decisions.

Main Methods:

• Detailed protocol for participant preparation, dynamometer setup, and alignment.
• Inclusion of isometric and concentric isokinetic knee extension/flexion testing at 60°/s, 180°/s, and 240°/s.
• Calculation of torque-velocity relationship using both two-point and multi-velocity regression analyses.

Main Results:

• Patients post-ACLR exhibited significantly reduced knee extensor torque-velocity relationships compared to the contralateral limb.
• The two-point method showed involved limb torque magnitude was approximately half that of the uninvolved limb.
• Multi-velocity analysis revealed a lesser slope in the torque-velocity relationship for the involved limb.

Conclusions:

• Multi-velocity isokinetic testing provides a more comprehensive assessment of quadriceps function post-ACLR than single-velocity measures.
• The torque-velocity relationship can identify subtle, persistent strength deficits impacting functional recovery.
• This approach offers a valuable tool for tracking rehabilitation progress and optimizing clinical management strategies.