The brachioradialis reflex (also known as supinator reflex''

is observed during a

neurological exam A neurological examination is the assessment of sensory neuron and motor responses, especially reflexes, to determine whether the nervous system is impaired. This typically includes a physical examination and a review of the patient's medical hist ...

by striking the

brachioradialis tendon The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way o ...

(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 Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...

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.

References

Reflexes {{med-diagnostic-stub