I love when patients walk in and I can easily show them how their body works. This past week, I was able to do that with a patient who couldn’t lift his arms over his head. In seconds, I was able to fix that issue with a simple maneuver. In doing so, I demonstrated how the upper neck is connected to shoulder function. Let me explain.
We’ve Got It All Wrong: The Body Isn’t a Bunch of Individual Parts
In the field of medicine, we’ve really done the human body a disservice by conceptualizing how it functions based on a single part or system. The body, however, is one interconnected machine, not a bunch of individual part and pieces. For instance, if you have shoulder pain or trouble lifting your arms overhead, most physicians are going to focus on the shoulder. If a physician is focused on the whole body, he or she might find that the shoulder problem is due to muscles in the neck that have weakened and become unstable. Irritated nerves in the neck can also present as problems lifting the shoulders overhead. Let’s zoom in a bit closer on the neck muscles and nerves.
Neck Instability: Muscles and Ligaments
Your neck is kept stable by muscles and ligaments. The muscles provide active stability to keep things aligned as you move. The ligaments act as passive stabilizers that prevent too much motion when the bones move one on the other. These pieces of living “duct tape” prevent things from getting misaligned.
Deep in the neck running along either side of the cervical spine are the deep stabilizing muscles. As shown in the video below, these are a series of small finger-like muscles that travel all the way down the spine, and their primary purpose is to keep the bones of the spine (vertebrae) stable. In the neck, this stability helps keep everything nicely aligned when moving or bending the neck.
When these muscles weaken, they can atrophy (shrink), and this creates neck instability and abnormal motion in the neck. This can cause the shoulder muscles, such as the trapezius, to pick up the slack and work overtime to help provide neck stability ( learn more about this by watching my video above ). Understandably, this can create pain, stiffness, or functional issues, such as difficulty lifting the arms overhead.
The ligaments in the neck are your last line of defense from too much movement of the vertebrae. They act like living pieces of duct tape that hold one bone to the other and prevent misalignment. For example, if the muscles fail, there needs to be something that prevents the bones from wrecking the disc or a nerve. This is done by your ligaments. For example, in the patient that I’ll discuss below, his ligaments allow too much motion of the C1 vertebra on the C2.
Irritated Neck Nerves
Irritated nerves in the neck can create shoulder issues in a couple of ways. First, the nerves that supply the shoulder muscles exit the spinal canal through the cervical spine in the neck. If one of these nerves becomes irritated or pinched in the neck, it can present as weakness of the shoulder muscles that help lift the arms, which can disrupt function. Oftentimes, because a physician may only be focused on the shoulder, an MRI finding such as an old rotator cuff tear may actually be an incidental finding but it’s attributed to the shoulder problem. Yet an examination of the neck might have determined there’s an irritated nerve at play.
My Patient: Why Can’t I Lift My Arms Overhead?
In the short video at the top of this post, I present the case of one of my patients to demonstrate how important the neck is in shoulder function in answering “Why can’t I lift my arms overhead?” While this patient actually has a congenital abnormality in his neck that is causing his neck instability, I’ve seen this same phenomenon for many years in patients who have upper neck instability either due to muscle atrophy or upper neck craniocervical junction (CCJ) instability (due to loose or damaged ligaments), so the effect is relative.
The patient in the video was born without a dens (odontoid process), which is a part of the C2 vertebra (the bone at the second level of the cervical spine in the neck). The dens actually stabilizes the C1 vertebra (the atlas) on the C2 vertebra (the axis). These two vertebrae together form the structure that allows the head to rotate (see video for the anatomy). Without the dens, this patient’s C1–2 moves too much, as demonstrated on an upper-neck DMX (live X-ray with motion) in the video, creating a great deal of upper-cervical instability.
You’ll see in the video that when I ask him to raise his arms overhead, he struggles. Why? He’s using his upper trapezius and levator scapula muscles not only to lift his arms but also to stabilize his neck. However, when I stabilize his head on his neck, he’s able to accomplish the task easily. Why? Because now those muscles only have to lift his arms, what they were designed to do, rather than pull double duty as a neck stabilizer and a prime mover.
We can use a rowboat as another example. Say you rowed out to the middle of a lake and tried to perform dead lifts with weight while in the unstable boat. You would expend a great deal more energy because your muscles are both lifting the weight and stabilizing the boat. Once you row onto shore and perform the same dead lifts on solid ground, you can lift more weight more easily as your muscles can just focus on lifting the weight. In fact, an entire industry has grown up around this phenomenon called Standup Paddleboard (SUP) yoga. This is yoga made more difficult by performing it while on an unstable paddleboard.
The upshot? In answer to “Why can’t I lift my arms overhead?” it’s easy to see that the reason my patient can’t do this is because his upper neck is unstable. When I stabilize his head on his neck from the outside, he has no issues. This is a great demonstration of how critical neck strength is in shoulder function. This is just one of the many systems in your body that are all interconnected. That includes how your feet control your knee position and how your back is critical for leg function. Hence, the next time you meet a doctor who only wants to talk about why your shoulder hurts or is weak, and doesn’t consider your neck in that equation, find a new doctor.