Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which neurological assessment would evaluate flexion below the knee?

1. Strength testing of quadriceps

2. Assessment of ankle dorsiflexion

3. Evaluation of knee flexion

4. Testing plantar reflex

The correct answer is: Evaluation of knee flexion

The assessment that evaluates flexion below the knee is the evaluation of knee flexion. This measure specifically tests the ability of the knee to bend, which involves the hamstring muscles located at the back of the thigh. When a clinician assesses knee flexion, they are directly observing the motion and function of the muscles that allow for flexing the leg at the knee joint. This is crucial for understanding muscle strength, motor control, and overall neurological function in the lower extremities. In contrast, strength testing of the quadriceps focuses on extending the knee rather than flexing it, which does not assess movement below the knee. Assessment of ankle dorsiflexion measures the upward movement of the foot at the ankle joint, not the knee joint, and does not provide insight into knee flexion. Testing the plantar reflex evaluates the function of the spinal cord and the neurological pathways associated with the reflex of the foot but does not directly assess flexion capabilities of the knee. Therefore, evaluating knee flexion is the most relevant assessment for determining the capability of flexion below the knee.