Neck & Shoulder

What It Is

Anterior scalene syndrome (also called scalenus anticus syndrome) describes symptoms caused when nerves, and sometimes blood vessels, are squeezed as they pass between the scalene muscles at the side of the neck. This gap, called the scalene triangle, is bordered at the front by the anterior scalene muscle, and it is the most common place for nerves to be squeezed in thoracic outlet syndrome (Camporese et al., 2022). So rather than being exactly the same thing, anterior scalene syndrome is one form of thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is the name for a group of conditions where nerves or blood vessels are squashed or irritated in the thoracic outlet, the narrow space between the collarbone and the first rib (AAOS, n.d.; NHS, 2023). This can cause pain in the neck, shoulder and arm, as well as pins and needles or numbness in the hand and fingers.

Common causes include an injury to the chest, neck or ribs, such as a car accident, being born with an extra rib in the neck (a cervical rib) or another difference in the shape of the first rib, and jobs or activities that involve lots of repetitive arm movements, such as building work or a lot of swimming (NHS, 2023; AAOS, n.d.). There are instances where doctors aren't able to find a cause. Treatment usually includes physiotherapy and medicines to ease pain, and most people improve with these (NHS, 2023; Cleveland Clinic, 2026), but injections and surgery are also options in some cases.

It is believed that the anterior scalene muscle can compress nerves and blood vessels around the front and side of the neck. So the symptoms in the arm vary between a dull ache, throbbing, sharp pain and a dead arm feeling.

What Causes Anterior Scalene Syndrome?

Different experts put the causes down to different underlying problems. As well as the causes above, poor posture, with the shoulders rounded forwards and the head in a forward position, can lead to or aggravate the condition, as can being overweight, having large breasts, or gaining a lot of muscle, for example through body building (NHS, 2023; AAOS, n.d.). Poor breathing mechanics may also play a part, as this can shorten the anterior scalene muscle and could potentially cause some compression. Improving your posture is an important part of treatment, because postural exercises help you sit and stand straighter, which lessens the pressure on the nerves and blood vessels (AAOS, n.d.).

Not a diagnosis — for more information, contact me or another trusted healthcare provider.

Symptoms

How It Feels

Signs & Symptoms

Which symptoms you have depends on what is being squeezed. Pressure on the nerves is much more common than pressure on the blood vessels (AAOS, n.d.).

Pressure on the nerves can cause a vague, aching pain in the neck, shoulder, arm or hand; pain, numbness or tingling on the inside of the forearm and in the ring and little fingers; and weakness that can make the hand clumsy (AAOS, n.d.)
Pins and needles may be worse at night and wake you up (NHS, 2023)
Pressure on the blood vessels can cause swelling, redness or other colour changes in the arm, or make the arm and hand feel cold and tire easily (AAOS, n.d.; NHS, 2023)
Overhead activities are often particularly difficult (AAOS, n.d.)

Treatment

Self-Care & Treatment

How to Treat Anterior Scalene Syndrome

If you have the nerve type of anterior scalene syndrome, physical therapy is usually the first treatment, with exercises to strengthen the shoulder muscles and improve your posture that, over time, help to reduce pressure on the nerves and blood vessels (Cleveland Clinic, 2026; Camporese et al., 2022; AAOS, n.d.; NHS, 2023). I can guide you through these exercises and use hands-on work for the neck and shoulder muscles alongside them. Massage is not one of the main treatments recommended for this condition, so it should be used alongside, not instead of, your exercise programme and medical care. See the My Approach tab for how I work.

1. Medication

AAOS OrthoInfo (n.d.) says that anti-inflammatory medicines (NSAIDs), such as naproxen and ibuprofen, can ease the pain and reduce swelling. (This medicine information comes from AAOS OrthoInfo, not from me. Always check with a pharmacist or your family doctor or nurse practitioner before taking any medicine.)

Treatments you may want to discuss with your family doctor or nurse practitioner

Options outside my scope

Prescription medicines: a doctor may prescribe medicines to help with pain, relax muscles, improve circulation or reduce the risk of blood clots (NHS, 2023).
Clot-dissolving treatment: if a blood clot forms in a vein or an artery (venous or arterial TOS), medicine given in hospital through a drip or a thin tube (catheter) can dissolve it, and blood-thinning medicine may also be prescribed (Cleveland Clinic, 2026).
Injections: a doctor may inject botulinum toxin into the muscles (Cleveland Clinic, 2026).
Tests: a doctor may arrange an X-ray, CT, MRI or ultrasound scan, or nerve and circulation tests (AAOS, n.d.; NHS, 2023).
Surgery: this may be offered if other treatments have not helped, or for serious problems such as blood clots. It may involve removing part of an abnormal first rib or an extra rib, or releasing a muscle that joins the neck and chest (AAOS, n.d.; NHS, 2023). Most people with the blood-vessel types of TOS need surgery (Cleveland Clinic, 2026).

How I can help (see the My Approach tab)

Hands-on work for the neck, chest and shoulder muscles

Shoulder-strengthening and posture exercises

Breathing and everyday habit advice

Tips

If you are prone to anterior scalene syndrome, change the everyday activities that aggravate your symptoms, such as heavy lifting or lifting objects above your head; changing your workstation layout may also help (AAOS, n.d.; Cleveland Clinic, 2026).
If you are overweight, losing weight can help, as extra weight stresses the shoulder muscles that support your collarbone (AAOS, n.d.).
Avoid carrying heavy bags on your shoulder, as this pushes the collarbone down and increases the pressure in the thoracic outlet (AAOS, n.d.).
Do simple exercises daily to keep your shoulder muscles strong; I can show you suitable ones. Stop any exercise that causes pain (AAOS, n.d.).
Have your symptoms checked and treated at an early stage rather than waiting for them to go away (Cleveland Clinic, 2026).

Treatment

My Approach

Anterior scalene syndrome is a squeeze on the nerves, and sometimes the blood vessels, heading to your arm as they pass between the muscles at the side of your neck. My aim is to give them more room: ease the tight muscles, get the collarbone and upper ribs moving, and change the postures and breathing habits that close the space.

Which path we take depends on your symptoms.

If your symptoms are mild: aching, pins and needles or numbness that come and go, with no weakness, I can treat you directly, as below.

If you have weakness in your arm or hand, numbness or other nerve signs that are getting worse, or swelling, colour changes or a cold arm: see your family doctor or nurse practitioner first. Once you have a plan from your medical team, I provide supportive care alongside it, and after surgery I need your surgeon's okay before hands-on treatment.

I start by assessing your neck, shoulders and posture, with tests of how your symptoms respond to arm positions, and a check of sensation, reflexes and strength. I'll also watch your breathing.

Hands-On Treatment

Myofascial, trigger point and gentle stretching work for the neck, upper back and shoulder-blade muscles
Light pressure near the collarbone, where pressing hard could squeeze the very nerves we're trying to free; symptoms may come on briefly while a muscle is worked and should ease when I let go
Work on the small chest muscle under the front of the shoulder only when it's clinically relevant and with your informed, written consent; you can say no at any time
Joint mobilisation for the collarbone and shoulder girdle, a breathing-linked release for the upper ribs, and gentle nerve glides

Breathing, Posture and Strength

Breathing high into the upper chest keeps the neck muscles working all day, so I'll teach you to breathe low into your belly
Shoulder-blade and shoulder strengthening, and postural exercises for sitting and standing
Gentle neck and chest stretches at home, after a warm shower
Advice on overhead work, heavy bags, phone-cradling and long desk sessions

Keep up your exercises even after you feel better. A suddenly cold, pale, painful arm, or throbbing pain, swelling and warmth in one arm, needs urgent help (see When to Get Urgent Help).

What to Expect

Typical Course

Typical course: For mild symptoms, I usually see people twice a week early on, then weekly, spacing out as you manage more on your own, with a reassessment at about 4 to 6 weeks; expect some improvement by about 3 months, and keep going with your exercises after you feel better. If you've needed medical care first, visits fit around your medical team's plan, and after surgery your surgeon sets the timeline.

What I Focus On

Assessment

Neck & Chest Release

Shoulder Girdle Mobility

Breathing

Postural Strength

Please read

When to See a Doctor First

When to Get Urgent Help

Throbbing or cramping pain, swelling, redness and warmth in one arm could be signs of a blood clot caused by TOS. Blood clots can be life-threatening if not treated quickly, so get urgent medical attention or call 911 for an ambulance the same day (NHS, 2023).
Call 911 or go to the emergency room at your nearest hospital if you have sudden breathlessness, sharp chest pain (which may be worse when you breathe in) and a cough or coughing up blood (NHS, 2023).

Sources

References

NHS (2023) Thoracic outlet syndrome. Available at: https://www.nhs.uk/conditions/thoracic-outlet-syndrome/ (Accessed: 7 October 2026).
American Academy of Orthopaedic Surgeons (n.d.) Thoracic outlet syndrome. OrthoInfo. Available at: https://orthoinfo.aaos.org/en/diseases--conditions/thoracic-outlet-syndrome/ (Accessed: 7 October 2026).
Cleveland Clinic (2026) Thoracic outlet syndrome. Available at: https://my.clevelandclinic.org/health/diseases/17553-thoracic-outlet-syndrome-tos (Accessed: 7 October 2026).
Camporese, G. et al. (2022) 'Diagnostic and therapeutic management of the thoracic outlet syndrome. Review of the literature and report of an Italian experience', Frontiers in Cardiovascular Medicine, 9, 802183. doi: 10.3389/fcvm.2022.802183

Massage therapy · Kitchener–WaterlooAnterior Scalene Syndrome

What It Is

What Causes Anterior Scalene Syndrome?

How It Feels

Signs & Symptoms

Self-Care & Treatment

How to Treat Anterior Scalene Syndrome

1. Medication

Treatments you may want to discuss with your family doctor or nurse practitioner

Tips

My Approach

Hands-On Treatment

Breathing, Posture and Strength

Typical Course

When to See a Doctor First

When to Get Urgent Help

References

Related Conditions

Book a session

Massage therapy · Kitchener–WaterlooAnterior Scalene Syndrome

What It Is

What Causes Anterior Scalene Syndrome?

How It Feels

Signs & Symptoms

Self-Care & Treatment

How to Treat Anterior Scalene Syndrome

1. Medication

Treatments you may want to discuss with your family doctor or nurse practitioner

Tips

My Approach

Hands-On Treatment

Breathing, Posture and Strength

Typical Course

When to See a Doctor First

When to Get Urgent Help

References

Related Conditions

Thoracic Outlet Syndrome

Cervical Radiculopathy (Pinched Nerve)

Cervical Somatosensory Dysfunction

Costoclavicular Syndrome

Book a session