The trapezius is a flat, triangle-shaped muscle in your back. It extends from your neck, down along the spine to about the middle of your back and across your shoulder blade. You have a right and left trapezius. These large muscles support your arms and shoulders, and are needed to raise your arms.
Use this interactive 3-D diagram to explore the left and right trapezius.
A trapezius strain is a common injury that can limit your range of motion and the strength in your arms. A strain occurs when the fibers in a muscle or tendon stretch beyond their normal limit. A strain can happen gradually from overuse or suddenly from an injury. Healing a trapezius strain may require nothing more than rest and ice. Exercising your trapezius may help strengthen it and keep it more flexible to reduce the risk of injury down the road.
Symptoms of a trapezius strain vary, depending on the cause of the injury as well as its severity. You may feel “knots” in the muscles in your neck and upper back. The trapezius will feel sore, and the muscle may spasm or cramp. A serious strain may also lead to swelling and inflammation.
Your neck and shoulder may also feel tight and stiff, providing a limited range of motion. You may have trouble turning your head from side to side. A trapezius strain may also leave one or both arms tingling or weak.
Trapezius strains can happen in one of two ways: through an acute injury or by overuse.
An acute muscle injury occurs suddenly when the muscle experiences trauma, such as a violent twist or collision. A bad fall can cause a trapezius strain. When there is a hard blow to the trapezius, there may be a bruise as well as other muscle strain symptoms. Pain and stiffness from an acute injury will be felt immediately.
Overuse injuries tend to occur when repetitive, low-impact activities are performed over a prolonged period of time. But you can also strain your trapezius through rigorous and repetitive activity, such as heavy weightlifting. When the trapezius or any muscle is overworked and does not have time to repair itself, a strain or other injury is likely.
Diagnosing a soft-tissue injury usually requires a physical exam and an imaging test. During the exam, your doctor will review your symptoms and talk about when and how the injury might have occurred. If there wasn’t an acute injury, and you have noticed symptoms gradually getting worse, try to recall when they started and what activities might be the triggers.
During the exam, your doctor will ask you to move your arm and neck into different positions. Your doctor may also move your neck, arm, or shoulder to get an idea of your range of motion, strength, and the location and trigger of pain.
An X-ray can’t reveal detailed images of muscle damage, but it can help determine whether your symptoms are due to a bone fracture. Magnetic resonance imaging (MRI) uses a strong magnetic field and radio waves to produce images of soft tissue (such as muscle, tendons, and organs). An MRI can help identify the precise location of a muscle strain and whether there is a complete muscle tear or just a strain.
A muscle injury is usually categorized by one of three grades:
- A Grade 1 injury is a mild muscle strain, involving less than 5 percent of a muscle’s fibers.
- A Grade 2 injury affects many more fibers, and is a much more serious injury. The muscle is not completely torn, however.
- A Grade 3 injury is not a strain, but a complete rupture of a muscle or tendon.
If you’ve been diagnosed with a trapezius strain, you’ll probably be advised to apply ice to the injured area and rest. You may also try ice and rest if you feel that you have a trapezius strain, but don’t think it’s serious enough to get a medical evaluation.
RICE (rest, ice, compression, elevation) is a good treatment system for ankles and knees, in particular, but compression and elevation aren’t always realistic for a trapezius strain.
A doctor may try to wrap your shoulder to compress the trapezius in order to reduce swelling. But this often isn’t necessary or practical, given that the injury may be in the middle of your upper back.
The goal of elevation is to reduce swelling at the injury site. This is accomplished by elevating the injury site above the level of the heart. But because the trapezius is already above the heart, you may not have to take any other steps other than elevating your head and shoulders somewhat while you sleep.
Kinesiology tape is a newer treatment for muscle strains. It’s a stretchy, elastic tape that’s placed on the skin over an injured muscle. The tape gently pulls the skin toward it, relieving pressure on the muscles and other tissue underneath. You may see basketball players, volleyball players, and other athletes sporting kinesiology tape during competitions. Though a relatively recent innovation, kinesiology has proven in some research to help relieve a trapezius strain.
When the injury goes beyond a strain and is a complete rupture of the muscle or tendon, surgery may be needed to repair the muscle or reattach a tendon to the bone or muscle from which it has detached.
Your recovery will depend upon the severity of the strain and how well it’s treated initially. If you rest the trapezius and ice it, a Grade 1 strain may take just two or three weeks to recover, while a more serious injury could require a couple of months.
Your doctor will probably advise you to ease your way back into your usual activities. Start with light activity and work your way up to your normal work or exercise routines.
Stretching and strengthening exercises may help prevent future trapezius strains.
One simple trapezius stretch is done by looking straight ahead with your shoulder relaxed. Lower your right shoulder and bend your neck to the left, as though trying to touch your left shoulder with your left ear. Hold for 20 seconds, then slowly straighten your neck and do the same on the right side. Here are a few other stretches for you to try.
For strengthening the trapezius, try an exercise called a scapula setting. Lie on your stomach with a pillow or towel under your forehead for comfort, if you want. With your arms at your sides, pull your shoulder blades together and down as far as you can and hold for 10 seconds. Try performing 1 set of 10 repetitions, 3 times a week. Try these other exercises as well.
Once you have recovered from a trapezius strain, you’ll want to take a few precautions to help avoid a similar injury down the road. One of the most important injury prevention steps you can take is to properly warm up before exercise. A light jog or some calisthenics helps get blood circulating in your muscles. Warm-up exercises also loosen up your muscles so they’re less likely cramp or freeze when needed. A similar cooling down routine after a workout is also important.
Make trapezius stretching and strengthening exercises part of your usual routine, and be careful when exerting your arms and shoulders when lifting something heavy. A trapezius strain may sideline you for a few weeks, but a more serious muscle tear could limit the use of a shoulder or arm for months.