biceps reflex

noun
variants: or biceps jerk

Medical Definition of biceps reflex

: an involuntary contraction of the biceps muscle of the arm produced by tapping upon its tendon The biceps reflex is usually tested by percussing the examiner's thumb held over the biceps tendon, with the elbow in a partially flexed position.— Frank P. Smith, Neurology and Neurosurgery, 2001