Biceps reflex is a reflex test that examines the function of the C5 reflex arc and the C6 reflex arc. The test is performed by using a

tendon hammer A reflex hammer is a medical instrument used by practitioners to test deep tendon reflexes. Testing for reflexes is an important part of the neurological physical examination in order to detect abnormalities in the central or peripheral nervous s ...

to quickly depress the biceps brachii tendon as it passes through the

cubital fossa The cubital fossa, chelidon, or elbow pit, is the triangular area on the anterior side of the upper limb between the arm and forearm of a human or other hominid animals. It lies anteriorly to the elbow (Latin ) when in standard anatomical position ...

. Specifically, the test activates the stretch receptors inside the biceps brachii muscle which communicates mainly with the C5 spinal nerve and partially with the C6 spinal nerve to induce a reflex contraction of the biceps muscle and jerk of the

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...

. A strong contraction indicates a "brisk" reflex, and a weak or absent reflex is known as "diminished". Brisk or absent reflexes are used as clues to the location of neurological disease. Typically, brisk reflexes are found in lesions of upper motor neurons, and absent or reduced reflexes are found in lower motor neuron lesions. A change in the biceps reflex indicates pathology at the level of

musculocutaneous nerve The musculocutaneous nerve arises from the lateral cord of the brachial plexus, opposite the lower border of the pectoralis major, its fibers being derived from C5, C6 and C7. Structure The musculocutaneous nerve arises from the lateral cord ...

, segment C5/6 or at some point above it in the spinal cord or brain.

References

Reflexes {{med-diagnostic-stub