Brachioradialis reflex explained

Brachioradialis reflex

The brachioradialis reflex (also known as supinator reflex http://www.medilexicon.com/medicaldictionary.php?t=46267) is observed during a neurological exam by striking the brachioradialis tendon (at its insertion at the base of the wrist into the radial styloid process (radial side of wrist around 4 inches proximal to base of thumb)) directly with a reflex hammer when the patient's arm is relaxing. This reflex is carried by the radial nerve (spinal level: C5, C6)

The reflex should cause slight pronation or supination[1] and slight elbow flexion. Contrary to popular belief, this reflex should not cause wrist extension and/or radial deviation, because the brachioradialis does not cross the wrist.

Notes and References

  1. Book: Springhouse. Neurologic Care. 4 July 2011. 1 July 2007. Lippincott Williams & Wilkins. 978-1-58255-706-9. 60–.