knee-jerk reflex


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pa·tel·lar re·flex

a sudden contraction of the anterior muscles of the thigh, caused by a smart tap on the patellar tendon while the leg hangs loosely at a right angle with the thigh.

knee-jerk reflex

knee-jerk reflex

pa·tel·lar re·flex

(pă-tel'ăr rē'fleks)
A sudden contraction of the anterior muscles of the thigh, caused by a smart tap on the patellar tendon while the leg hangs loosely at a right angle with the thigh.
Synonym(s): knee reflex, knee-jerk reflex, quadriceps reflex.