biceps jerk

Last reviewed 01/2018

The biceps jerk is tested by placing one finger on the biceps tendon and then tapping it with a tendon hammer. The hammer should not be wielded, and instead should allowed to fall with gravity on the positioned finger.

If the reflex is intact then there is a brisk contraction of the belly of biceps, and consequent flexion of the elbow, followed quickly by relaxation.

If the reflex is absent then ask the patient to clench their teeth - a form of reinforcement - and test for the reflex again.

An increased reflex occurs in upper motor neurone lesion.