Physiology Tapping the patellar tendon with a reflex hammer produces a brief contraction of the knee extensors. What is the cause of the muscle contraction? A Elastic rebound of muscle connective tissue B Golgi tendon organ response C Muscle spindle activation D Muscle spindle unloading 💡 Explanation Tapping the patellar tendon with a reflex hammer produces a brief contraction of the knee extensors. What is the cause of the muscle contraction? ✓ Correct Answer: C. Muscle spindle activation