Definition of knee jerk
: an involuntary forward kick produced by a light blow on the tendon below the patella
First Known Use of knee jerk
Medical Definition of knee jerk
: an involuntary forward jerk or kick produced by a light blow or sudden strain upon the patellar tendon of the knee that causes a reflex contraction of the quadriceps muscle—called also patellar reflex
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Medical Dictionary: Definition of "knee jerk"
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