National Physical Therapy Examination (NPTE) Practice Exam

What mechanical action of the quadriceps is significant for knee stability after PCL reconstruction?

1. Prevention of anterior tibial translation

2. Control of dynamic stabilization

3. Prevention of posterior tibial translation

4. Facilitation of flexion movements

The correct answer is: Prevention of posterior tibial translation

Following PCL reconstruction, the quadriceps play an essential role in maintaining knee stability. The prevention of posterior tibial translation is particularly significant as the posterior cruciate ligament (PCL) typically functions to inhibit backward movement of the tibia relative to the femur. After surgery, the stability of the knee joint can be compromised, especially during weight-bearing activities and movements that might otherwise cause posterior tibial translation. The quadriceps muscle group, particularly through its action during knee extension, counteracts this posterior translation. When the quadriceps contract, they create a stabilizing force across the knee joint, preventing the tibia from displacing too far rearward. Therefore, ensuring that the quadriceps are strong and functioning effectively post-rehabilitation is crucial for restoring knee stability and ensuring successful recovery after PCL reconstruction. This emphasis on posterior translation prevention is fundamental for individuals in the postoperative phase as it aids in overall joint mechanics and function.