What happens to the patellar tendon reflex after running on the spot and why does this happen? please help, this is urgent

Patellar reflex: The patellar tendon reflex is an involuntary reflex arc that occurs in response to rapid stretching of the tendon. When the tendon is tapped with a reflex hammer, involuntary stimulation of the quadriceps muscle (e.g., knee extension) is produced. Running and other exercises that promote fatiguability of the quad muscles can blunt, but typically cannot eliminate, the effect of the reflex itself.