Quadriceps Strength and Movement Patterns in Patients After ACLR Who Pass a Clinic-Based Return-to-Sport Testing...

Area of Science:

• Orthopedic surgery
• Sports medicine
• Rehabilitation science

Background:

• Return to sport (RTS) testing after anterior cruciate ligament reconstruction (ACLR) is crucial for reducing re-injury rates.
• Existing RTS protocols often require specialized equipment and resources, limiting accessibility for many clinicians.

Purpose of the Study:

• To determine if patients who pass clinic-based RTS evaluations exhibit residual strength or biomechanical deficits compared to gold-standard laboratory measures.
• To validate accessible RTS testing against objective laboratory assessments.

Main Methods:

• Participants completed clinic-based RTS tests (strength, hop tests, functional scales).
• Laboratory testing included isometric and isokinetic strength (quadriceps, hamstrings), rate of torque development (RTD), and 3D motion analysis during jumping.
• Paired t-tests analyzed interlimb differences.

Main Results:

• Passing RTS tests correlated with ≥90% limb symmetry in isometric quadriceps strength and met specific strength targets.
• Significant deficits were observed in involved limb quadriceps strength (7.6% lower isometric, 4.9% lower isokinetic) and RTD (up to 20.9% lower).
• Biomechanical analysis revealed impaired limb loading (6.6%-67% differences) and increased hamstring strength (4.7%) in the involved limb.

Conclusions:

• Clinic-based RTS testing may not fully capture all residual deficits after ACLR, particularly in quadriceps RTD and movement biomechanics.
• Despite passing clinical RTS criteria, patients can exhibit persistent strength deficits and altered movement patterns.
• Further refinement of RTS testing is needed to ensure comprehensive patient readiness for sport post-ACLR.