Have you ever wondered why your leg kicks when the doctor taps your knee with that little rubber hammer? It's because of your reflex. A reflex is an involuntary (say: in-VAHL-un-ter-ee), or automatic, ...

vch.ca The extensor mechanism (EM) of the knee comprises the quadriceps muscles and tendon, the patella, patellar tendon and supporting retinaculum (figure 1). Injuries of the EM are common and may be ...