You’re sitting in a doctor’s office because your hand feels like it’s falling asleep every time you try to reach for something on a high shelf. Or maybe you’re a swimmer whose arms turn into lead weights halfway through a lap. You’ve heard the term Thoracic Outlet Syndrome—TOS for short—and now the clinician is asking you to put your arms up like you’re being held up in a vintage Western movie. They want you to open and close your fists for three minutes. This is the Roos test for thoracic outlet syndrome, and honestly, it’s one of the most polarizing physical exams in the world of orthopedics.
Some surgeons swear by it. Others think it’s about as reliable as a weather forecast in a hurricane. But if you’re dealing with that weird, nagging numbness or a "heavy" feeling in your limbs, understanding what this test actually does—and what it doesn't—is basically step one in getting your life back.
What is the Roos Test Actually Trying to Find?
TOS isn't one single "thing." It’s more like a traffic jam. Your nerves and blood vessels (the brachial plexus and the subclavian artery/vein) have to pass through a tiny, crowded tunnel between your neck and your shoulder. This area is the thoracic outlet. If your first rib is a bit high, or your scalene muscles are too tight, or you’ve got an extra "cervical rib" you were born with, that tunnel gets cramped.
The Roos test for thoracic outlet syndrome, often called the Elevated Arm Stress Test (EAST), is designed to intentionally cramp that space even further.
By lifting your arms into 90 degrees of abduction and external rotation, you're essentially putting the neurovascular bundle on a rack. When you start pumping your hands, you’re demanding blood flow and nerve signaling while simultaneously pinching the hose. If you have TOS, the "hose" kinks. Your symptoms don't just "show up"—they explode.
David Roos, the vascular surgeon who popularized this back in the 60s, argued that this specific movement replicates the functional demands of daily life. Think about brushing your hair. Driving. Painting a ceiling. If you can’t last three minutes without your arm turning white, blue, or numb, something is clearly wrong in that narrow corridor of bone and muscle.
How the Test Goes Down (The Three-Minute Marathon)
Don't expect a quick tap on the knee. This is an endurance trial.
📖 Related: How to Perform Anal Intercourse: The Real Logistics Most People Skip
- You stand or sit up straight. No slouching.
- You bring your arms up to the side, elbows bent at 90 degrees, like you’re making a "goal post" sign.
- You keep your elbows slightly behind the frontal plane of your body.
- You begin slowly opening and closing your fists.
That’s it. But here’s the kicker: three minutes is an eternity when your nerves are screaming. A "positive" result isn't just getting tired. Everyone gets tired. Your deltoids will burn. That’s normal. A positive Roos test for thoracic outlet syndrome involves the reproduction of your actual symptoms. We're talking profound heaviness, "pins and needles" (paresthesia), or the hand literally changing color because the blood can't get through.
I’ve seen patients who have to drop their arms within 30 seconds because the pain becomes unbearable. That’s a massive red flag.
The False Positive Problem: Is It Overrated?
We have to be real here. The medical literature is kind of a mess regarding how accurate this test is. Some studies, like those often cited in the Journal of Vascular Surgery, suggest it’s great for screening. But others point out a glaring flaw: healthy people often fail it too.
In one famous study, a significant percentage of people with zero history of neck or arm pain couldn't make it to the three-minute mark without feeling "something." This leads to "false positives." If a doctor relies solely on the Roos test, they might diagnose you with TOS when you actually have a herniated disc in your neck or carpal tunnel syndrome.
Nuance matters. A skilled physical therapist won't just look at whether you dropped your arms. They’ll look at why. Did your pulse vanish? (That points to vascular TOS). Did your fingers go numb in a specific pattern? (That’s neurogenic). If you just got "tired," it’s probably just weak shoulders, not a surgical emergency.
Understanding the Sub-Types of TOS
When performing the Roos test for thoracic outlet syndrome, the clinician is trying to differentiate between three distinct flavors of the condition. You need to know which one you're hunting for:
👉 See also: I'm Cranky I'm Tired: Why Your Brain Shuts Down When You're Exhausted
- Neurogenic TOS (nTOS): This is 95% of cases. It’s the nerves getting squashed. You’ll feel tingling in the pinky and ring finger mostly.
- Venous TOS (vTOS): The vein gets compressed. Your arm might swell up or look slightly purple/blue. This is the "Paget-Schroetter syndrome" territory—serious stuff that often hits young athletes.
- Arterial TOS (aTOS): The rarest and most dangerous. The artery is pinched. Your hand might turn cold and pale.
The Roos test hits all of these, but it's particularly provocative for nTOS. If your symptoms are purely neurological, the "heaviness" you feel during the test is your nerves literally running out of oxygen. It’s a terrifying feeling, but it’s a vital piece of the diagnostic puzzle.
Why Your Posture During the Test Changes Everything
If you’re doing this at home or in a clinic, watch your shoulders. A lot of people "cheat" by shrugging their shoulders up toward their ears as they get tired. This actually opens the thoracic outlet slightly by lifting the clavicle, which might mask a positive result.
Conversely, if you have a "slumping" posture—what we call depressed scapulae—you’re already pre-compressing the area. You might "fail" the test instantly, but the fix might be as simple as strengthening your upper trapezius to lift your shoulder girdle back where it belongs.
It’s also worth mentioning the "Adson’s Test" or the "Wright’s Hyperabduction Test." Usually, a doctor will do these alongside the Roos test. They involve moving your head or holding your breath to see if your pulse disappears. If you fail the Roos test and the Adson’s test, the likelihood that you actually have TOS goes way up. One test is a guess; three tests are a pattern.
The Reality of Treatment After a Positive Result
So, you failed the test. Your arm went numb at the two-minute mark. What now?
First, don't panic. Surgery—removing a rib—is usually the last resort. Most people (around 80%) get better with dedicated physical therapy. We focus on "opening the window." This means stretching the pec minor and the scalenes while strengthening the muscles that hold the shoulder blade in place.
✨ Don't miss: Foods to Eat to Prevent Gas: What Actually Works and Why You’re Doing It Wrong
If the Roos test for thoracic outlet syndrome was positive, your PT will likely use it as a benchmark. You might start out only being able to do 30 seconds. After a month of therapy, if you can go two minutes, you know the pressure on those nerves is lifting. It’s a functional yardstick.
There are cases where the test remains positive despite therapy. That’s when we look at Botox injections into the scalene muscles to force them to relax, or imaging like a CT Angiogram to see if there’s a physical bone blockage that no amount of stretching will ever fix.
Actionable Steps: What to Do Right Now
If you suspect you have TOS, don't just rely on a YouTube video to self-diagnose. Here is the actual path forward:
- Perform a self-check but record the "why": Try the Roos position for 90 seconds. Don't just note that it "hurt." Note exactly where: Was it the neck? The elbow? The ring finger? Did the skin color change?
- Check your workspace: If you’re a "keyboard warrior," your desk setup might be fueling the fire. High armrests can push the humerus up into the outlet, mimicking TOS symptoms.
- Consult a specialist: Specifically, look for a vascular surgeon or a physiatrist who specializes in the upper extremity. General practitioners often miss TOS because it's a "diagnosis of exclusion."
- Ask for "Dynamic" Imaging: Standard X-rays or MRIs where you’re lying flat often look normal. You need imaging where your arms are overhead—the same position as the Roos test—to see the compression in real-time.
The Roos test for thoracic outlet syndrome isn't perfect, but it’s the most honest conversation your body can have with a clinician about how it handles the stress of movement. If your nerves are being strangled, this test will breathe life into that reality so you can finally start the right treatment.
Focus on the quality of the sensation, not just the clock. If the tingling matches what wakes you up at night, you’ve found your smoking gun.
---