The triceps reflex is a deep tendon reflex that elicits involuntary contraction of the triceps brachii muscle. It is sensed and transmitted by the radial nerve. [1] The reflex is tested as part of the neurological examination to assess the sensory and motor pathways within the C7 and C8 spinal nerves. [2]
The test can be performed by tapping the triceps tendon [3] with the sharp end of a reflex hammer while the forearm is hanging loose at a right angle to the arm. A sudden contraction of the triceps muscle causes extension, and indicates a normal reflex. [4] [5]
The arc involves stretch receptors in the triceps tendon, from which information travels along the radial nerve, through the C7/C8 nerve root to the spinal cord, and the motor signal for contraction returns through the radial nerve.
An absence of reflex can be an indicator of several medical conditions: Myopathy, neuropathy, spondylosis, sensory nerve disease, neuritis, potential lower motor neuron lesion, or poliomyelitis. [6]
Other medical problems that may cause irregular reflexes include Hyperthyroidism.