The term “Erb’s Point” refers to two completely separate anatomical landmarks in medicine, one neurological and one cardiovascular, both named after the German neurologist Wilhelm Heinrich Erb (1840–1921). This dual usage can be confusing, as the two locations are in different body regions and serve distinct diagnostic and clinical purposes. Erb is primarily known for his work in neurology, but he also contributed to general medicine, which explains the two different eponyms.
Erb’s Point of the Neck
The neurological Erb’s Point is a specific area in the neck that serves as a major junction for several nerves. This landmark is located on the skin surface, approximately 2 to 3 centimeters above the collarbone (clavicle). To find its location, a healthcare professional traces the posterior border of the sternocleidomastoid muscle.
Deep beneath this surface point, a complex convergence of nerve fibers forms the upper trunk of the brachial plexus, a network that supplies the entire arm, shoulder, and hand. At this precise spot, the ventral rami, or roots, of the fifth and sixth cervical spinal nerves (C5 and C6) unite.
Six different nerves meet or pass through this concentrated location, including the C5 and C6 nerve roots, the suprascapular nerve, and the nerve to the subclavius muscle. This upper trunk quickly divides into its anterior and posterior divisions, making this a highly concentrated and vulnerable neurological hub. Historically, Erb used electrical stimulation at this supraclavicular spot to elicit contractions in the arm muscles.
Clinical Relevance of the Brachial Plexus Erb’s Point
The neurological point’s most widely known clinical relevance stems from its vulnerability to injury, which can result in Erb’s Palsy. This partial paralysis occurs when the C5 and C6 nerve roots are stretched or torn, typically due to significant trauma. The injury often involves excessive stretching of the neck, such as a severe fall onto the shoulder or, most commonly, shoulder dystocia during childbirth.
The resulting damage affects the nerves controlling the shoulder and upper arm muscles, including the musculocutaneous, axillary, and suprascapular nerves. Patients with Erb’s Palsy experience weakness or paralysis in the muscles responsible for moving the shoulder and flexing the elbow. This often leaves the affected arm hanging at the side, medially rotated with the forearm extended, a posture sometimes described as the “waiter’s tip” position.
This anatomical location is also utilized in pain management and diagnostic procedures. Clinicians use Erb’s Point as a landmark for performing nerve blocks, injecting medication to temporarily block pain signals from the shoulder and upper arm. It is also a standard site for electrophysiological testing to measure nerve conduction times and assess the extent of nerve damage.
Erb’s Point of the Heart
In a completely different context, Erb’s Point refers to a specific area on the chest wall used for listening to heart sounds, a practice known as auscultation. This cardiovascular point is positioned on the left side of the sternum (breastbone) in the third intercostal space, which is the gap between the third and fourth ribs.
This landmark is distinct from the four traditional auscultation points named after the heart valves they monitor. Erb’s Point is sometimes called the “fifth auscultation point,” providing a unique acoustic window to the heart. Due to its central location, it is considered the ideal place to listen for the combined sounds of both the aortic and pulmonic valves closing.
The ability to hear both the S1 (“lub”) and S2 (“dub”) heart sounds clearly makes this area useful for detecting abnormal sounds like heart murmurs. It is often the clearest location to detect murmurs associated with aortic regurgitation, a condition where the aortic valve does not close tightly. The cardiac Erb’s Point functions as a general assessment area for overall heart valve function.
Distinguishing the Two Anatomical Locations
The shared name for these two landmarks is a direct result of Wilhelm Heinrich Erb’s broad medical career. The two points are separated by function, location, and the medical specialty that uses them. The neurological Erb’s Point is a true anatomical convergence of nerve tissue located in the supraclavicular region of the neck. Its function relates to motor control and sensation in the arm, making it primarily relevant in neurology and orthopedics.
In contrast, the cardiac Erb’s Point is a surface landmark on the chest wall, not a specific underlying anatomical structure like a nerve trunk. Its role is purely diagnostic, serving as an optimal site for medical professionals to place a stethoscope for auscultation. Located at the left sternal border in the third intercostal space, its significance lies within cardiology for assessing valve function and identifying murmurs. The key difference is that the neck point is a physical structure prone to injury, while the heart point is a designated listening post for sound.