Why lifting the arm can hurt the upper back: our reading of the anatomyEmerging evidence
As the arm rises, the shoulder blade turns on the ribs, and the neck, the upper spine and the ribs move with it. That is our reading of the anatomy, not a tested explanation, but it is why pain at the shoulder blade can come from the muscles that move the blade, the rotator cuff, the small joints of the upper spine and ribs, or a trapped nerve in the neck.
Pain in the upper back is common: 15% to 34.8% of adults have it over a year, more often women, often with pain elsewhere. But no study counts the causes of upper back or shoulder blade pain when you lift your arm, so this guide's map is built from pain-mapping studies, reviews of single conditions and health-service pages, and says so. Where it hurts and what comes with it are the best clues.
Sources 1, 2, 3
The shoulder blade muscles, and the trouble with knotsEmerging evidence
An ache along the inner edge or top corner of the blade that builds while you hold the arm up (doing your hair, painting, a high shelf, a long reach at a desk) and eases when you lower it, tender to press, points to the muscles that move and hold the blade: the trapezius, the rhomboids and the levator scapulae. Holding the arm out to the side works the trapezius at about 97% of its maximum, and trapezius muscle pain is common in office workers.
These sore spots are often called knots or trigger points, but examiners don't reliably agree where they are: across 9 studies, agreement on a taut band ranged from no better than chance to good, and the review concluded that examination "cannot currently be recommended as a reliable test". The trials that eased this kind of pain used strength training.
Sources 4, 5, 6
The rotator cuffStrong evidence
The rotator cuff is the commonest cause of shoulder pain. NHS inform describes pain at the shoulder and upper arm, worse lifting the arm above shoulder level, which "can spread towards the neck or down the arm". A painful arc, pain partway up as the arm lifts out to the side, makes cuff pain about twice as likely, and its absence makes it less likely (55 patients). No study we found gives how often cuff pain is felt at the shoulder blade, so when the pain is mainly at the shoulder, our shoulder guides come first.
Sources 7, 8, 9
A trapped nerve in the neckStrong evidence
With a trapped nerve in the neck (cervical radiculopathy), shoulder blade pain was described in 72% of 81 studies, alongside neck pain (88%) and arm pain (85%), and it "may precede arm pain by several weeks". In 50 people having surgery, it came before the arm symptoms in 70%, between the blades with the lowest neck nerve roots. Shoulder blade pain on its own, with no pain anywhere else, was rare (2% of studies).
Pain, pins and needles or numbness down the arm point to the neck. Some people find the pain eases with the hand resting on top of the head, though that sign misses many cases (it was positive in 17% to 78% of people with a trapped nerve across 3 studies). It is commonest at 50 to 54.
Sources 2, 10, 11, 12, 13, 14
The joints of the upper spine and ribs, and a winging shoulder bladeEmerging evidence
The small joints of the upper spine and the joints where the ribs meet it send pain nearby, with a lot of overlap: in 15 people, the joints at the base of the neck and the top of the upper back sent pain above the blade, to its upper corner and to the middle of the blade, and rib joints gave a deep, dull ache over the joint in 8 volunteers. A catch beside the spine on reaching, twisting or breathing in fits this pattern.
A shoulder blade that sticks out (winging) is rare. Weakness of the serratus anterior, from its nerve, lifts the inner edge of the blade, often with pain at the rhomboids and levator scapulae; most people recover over 1 to 24 months, but about a quarter keep some winging or weakness. Neuralgic amyotrophy, an inflammation of the shoulder nerves, starts with severe, continuous pain for about 4 weeks before weakness appears, often of the nerve to the serratus anterior or the nerve over the blade (71% of 246 people), and is commoner than once thought: about 1 in 1,000 people a year in Dutch general practice.
Sources 3, 15, 16, 17, 18, 19, 20, 21
The heart, lungs, aorta and gallbladder come firstStrong evidence
Lifting and carrying are effort, and angina can come on with arm effort and ease within minutes of rest. The NHS angina page lists pain spreading to the arm, neck, jaw, shoulder, stomach or back among its 999 signs. The NHS heart attack page doesn't mention the back, but the British Heart Foundation lists upper back pain among women's heart attack symptoms, and in a pooled analysis women were less likely than men to have chest pain with a heart attack.
Sudden breathlessness with chest or upper back pain can be a clot in the lung, and a sudden tearing pain a tear in the aorta, the body's main artery (90% of people with one have severe pain and 84% sudden pain). NHS inform says gallstone pain may spread to the side or shoulder blade, and the NHS says pain from an inflamed gallbladder spreads towards the right shoulder. A tumour at the top of the lung (3% to 5% of lung cancers) often starts with shoulder pain. These are rare, but some need help the same day or a 999 call.
Sources 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32
Other causes the warning signs coverStrong evidence
The NHS gallstones page sends sudden, severe tummy pain, pain spreading from the tummy to the back with being sick, a very high temperature or yellow skin to 999 or A&E. The NHS cervical spondylosis page lists pain between the shoulder blades among the neck signs that need a same-day check, and problems walking, loss of bladder or bowel control or sudden clumsiness as 999 signs of pressure on the spinal cord. Shingles can cause a burning or tingling band of pain a few days before the rash appears.
Polymyalgia rheumatica causes pain and stiffness in both shoulders, often the neck and hips too, mostly over 50, with morning stiffness lasting more than 45 minutes. With thin bones, a cough, a sneeze or a minor fall can partly collapse a bone of the spine, the NHS osteoporosis page says. After a fall, a shoulder that looks out of place needs A&E.
Sources 33, 34, 35, 36, 37, 38
Can't lift your arm, and left or right
Most often pain stops the lift, and someone else can raise the arm further than you can: that is the rotator cuff pattern. Real weakness is different. Sudden weakness after a fall or a jerk can be a cuff tear (same day); weakness after days or weeks of severe pain can be neuralgic amyotrophy; weakness that keeps getting worse, or clumsy hands, needs an urgent GP appointment; and a sudden weak or numb arm with a drooping face or slurred speech is a stroke (999).
The side is a clue, not an answer. The heart can send pain to either arm and to the back; gallstone pain usually sits under the right ribs and can spread to the shoulder blade; and muscles, joints and the neck can hurt on either side. Pain at one shoulder blade when you lift the other arm usually comes from the muscles and joints that brace the trunk as the arm moves (our reading).
Sources 20, 39, 40, 22, 29
What a scan shows, and what it doesn'tStrong evidence
Scans mislead here: disc bulges showed on neck magnetic resonance imaging (MRI) in 87.6% of 1,211 people without symptoms, and 73% of 90 people without upper back pain had findings on an MRI of the upper back. NHS inform says scans and X-rays are not usually needed for mechanical neck pain or a trapped nerve.
A scan matters for a trapped nerve that isn't improving or is getting weaker, a possible spinal fracture with thin bones (an X-ray or scan through your GP), and the heart, lungs or gallbladder, where each NHS page names its own tests. A winging shoulder blade is checked with nerve tests (electromyography and nerve conduction studies).
Sources 41, 42, 43, 40, 37, 17
How it usually goesEmerging evidence
NHS inform expects neck problems to begin to settle within 8 weeks, with the biggest change in the first couple of weeks, and shoulder problems within 6. The NHS says shoulder pain usually takes 2 weeks to start to ease and can take 6 months or longer; only half of new shoulder episodes recover completely within 6 months, and in a pooled analysis neck pain fell from 64 to 35 out of 100 by 6.5 weeks but was still 42 at a year. A trapped nerve in the neck usually starts to improve within 12 weeks and can take up to a year. No one can promise a date.
Sources 39, 44, 45, 46, 47, 40
