The trapezius muscle moves the shoulder blade and neck

The trapezius muscle connects the neck and spine to the shoulder blade

Each trapezius is flat and triangular. Its base lies along the midline of the back and its tip points toward the shoulder blade ^[1]. It starts along the back of the skull and the spine. It attaches to the collarbone, the acromion and the spine of the shoulder blade ^[1].

At rest it is the largest muscle that suspends the shoulder blade on the chest ^[1]. It also extends the head and neck, tilts them to the side of the contraction and turns them to the opposite side ^[1].

Neck pain often follows awkward sleep or long hours at a desk

The most common causes of neck pain are a neck locked in an awkward position during sleep, bad posture such as sitting at a desk for a long time, and an injury such as whiplash from a traffic accident or fall ^[2].

Some simple habits may help prevent neck pain ^[2].

• When sleeping, keep your head at the same height as the rest of your body ^[2].
• Sit upright, roll your shoulders back gently and bring your neck back ^[2].
• Avoid holding your neck in one position for a long time ^[2].
• Avoid sleeping on your front and avoid twisting your neck in bed ^[2].

Shoulder pain often feels worse when you use the arm

Pain and stiffness can last for months or years, and pain is often worse while using the arm or shoulder ^[3]. Neck pain can also come with stiffness ^[2]. Research on upper trapezius muscle pain measures both pain and pressure pain threshold, which is how sensitive the area is to pressure ^[4].

• Pain that is worse when you use your arm or shoulder ^[3].
• Pain and stiffness that do not go away over months or years ^[3].
• Neck pain or stiffness ^[2].

Do not self-diagnose. A health professional will examine you to work out the cause, and may send you for tests such as an X-ray ^[3].

Gentle movement and heat or cold packs may ease shoulder pain

1. Stay active and gently move your shoulder ^[3].
2. Use pain relief so you can keep moving. For neck pain, the sources name paracetamol, ibuprofen or ibuprofen gel ^[2]. Ask a pharmacist which option suits you ^[3].
3. Try a heat or cold pack on the sore area, wrapped in a tea towel ^[3][2].
4. Stand up straight with your shoulders down and gently back. Sit with a cushion behind your lower back ^[3].
5. Try shoulder exercises to help stop pain returning, and ask a clinician which ones suit you ^[3]. For neck pain, neck flexibility exercises may help ^[2].

A pharmacist can suggest pain relief, such as tablets, creams or gels, and heat or cold packs ^[3].

Community musculoskeletal services may offer physical therapy in many areas

You usually need to follow self-care for 2 weeks before shoulder pain starts to ease. Recovery can take 6 months or longer ^[3]. Most neck pain lasts only a few weeks ^[2].

See a primary care doctor if shoulder pain is getting worse or has not improved after 2 weeks, or if it is very hard to move the arm ^[3]. For the neck, see a primary care doctor if pain lasts beyond a few weeks, painkillers have not worked or you are worried ^[2].

In many areas, community musculoskeletal services can offer help such as physical therapy without a referral ^[3][2]. Treatment depends on the cause. It may include stronger medicine or injections, home exercises or referral to a specialist ^[3]. If pain continues after physical therapy ends, you can go back to your primary care doctor or refer yourself back to the service ^[3].

Studies on upper trapezius myofascial pain have tested photobiomodulation therapy. A review of 17 studies with 944 patients reported reduced pain and higher pressure pain threshold, with larger effects when it was combined with exercise ^[4]. The quality of evidence was low to medium, which limits confidence in the results ^[4]. Trials of percutaneous nerve stimulation reported short-term improvements in pain and sensitivity, but methods varied widely ^[5]. A licensed clinician can say whether any option suits your situation ^[3].

Trapezius palsy often goes undiagnosed after spinal accessory nerve injury

Trapezius paralysis most commonly results from injury to the spinal accessory nerve, which supplies most of the muscle's movement ^[1]. The diagnosis is often missed or delayed. This can sometimes lead to unnecessary shoulder surgery ^[1].

Electromyography with nerve conduction studies can confirm it ^[1]. Some people with a temporary nerve injury may be helped without surgery ^[1]. If shoulder pain comes with weakness that does not improve, talk to a licensed clinician about your own situation ^[3][1].