The biceps reflex is a type of tendon reflex which occurs when a muscle of the bicep in the arm is struck. A biceps reflex test is performed by medical professionals to evaluate the cervical spinal nerve 5 (C5) and 6 (C6) reflex arc. For the test, specific receptors in the brachii muscle of the biceps are activated by gently pressing or tapping the muscles with a tendon hammer. This causes the nerves to react and the forearm to contract or jerk. This movement is involuntary and involves communication only with the spinal cord and not the brain.
The strength of the reflex gives clues as to the possibility and location of neurological disease or damage. A normal or strong reaction is known as a brisk reflex and generally indicates no damage or pressure to the C5 or C6 nerve. A weaker reflex, known as diminished, may indicate a problem in the C5 or C6 area. Conditions which may be screened for with the biceps reflex include nerve-root compression, hyperplasia, and even an electrolyte imbalance.
A person with a compressed or irritated C5 nerve root may have symptoms such as pain in the upper arm, shoulder, and neck, as well as numbness or tingling in the upper arm. C6 nerve compression or irritation has similar pain symptoms as the C5, which may also be combined with numbness or tingling of the lower arm. The biceps reflex test is helpful for medical professionals to locate the true nature of these symptoms in a patient and effectively treat the condition.
If damage or irritation of the C5 or C6 nerves is suspected due to an abnormal biceps reflex, a doctor may advise more testing to pinpoint the exact condition. A general practitioner who suspects damage to this area may refer their patient to a specialist, who can administer the best treatment. These treatments may include physical therapy, medications, or even surgery to correct severe conditions.
The biceps reflex is not as well known as patellar, or “kneejerk” reflex, and is not normally part of a routine checkup. Normally a person would not have the biceps reflex test unless he or she is experiencing symptoms of nerve root problems. Unfortunately, not every patient experiences the same symptoms for the same conditions, so many may simply ignore their pain or numbness for prolonged periods of time. When this happens, extensive damage to the nerve is possible, and eventually the bicep reflex may become nonexistent. This could mean serious treatment is needed right away, or even that the damage has passed the point of treatment and is permanent.