Trapezius muscles are large, paired, triangular muscles in the back of your neck and upper back. They extend down your back, but they’re mostly involved in the movements of the shoulder girdle. Because of this, they're considered muscles of the upper arms rather than the back.
The trapezius muscle controls many movements of the shoulder and arm. You use it a lot when you throw, and it's also involved in moving your head and neck.
If you have a strained or “pulled” trapezius muscle, you may feel mild or severe pain in your upper back area, shoulders, or neck.
What Is a Trapezius Muscle Strain?
Muscle strain, also called a pulled muscle, is a term used to describe a partial or complete tear of a muscle. Muscle strains happen when there is so much force on your muscle that the tissues tear. This can happen within the muscle itself, where the muscle and tendon meet, or in the tendon where the muscle attaches to the bone.
A strain in this muscle is different from an upper back sprain. A sprain happens when a ligament, or band of tissue that connects bones together at joints, is stretched or torn.
If you strain your trapezius muscle, the pain may be mild or severe, depending on how badly you’re injured.
There are three grades of muscle strains:
Grade I strain. This is the mildest kind, with only a few fibers torn or stretched. Your muscle may be tender but you have normal strength in it.
Grade II strain. In this type of moderate strain, more fibers are injured and the pain and tenderness are more severe. A grade II strain usually brings on swelling, loss of strength, and sometimes bruising.
Grade III strain. This type of strain tears the muscle all the way through. You may feel a popping sensation as the muscle rips in two or tears away from its tendon. There is usually a good bit of pain, swelling, and discoloration. This is a serious injury that causes a complete loss of muscle function. You may notice an obvious dent or gap under the skin where the muscle split.
What Causes a Trapezius Muscle Strain?
An acute or a chronic injury causes it.
An acute injury happens suddenly. This is due to trauma from something like a hard fall or a collision. It can also happen with weightlifting or contact sports. You’ll feel pain and tenderness immediately. You may also have a bruise or other symptoms.
Trapezius strains can also be caused by chronic or overuse injuries. This occurs when you do repetitive, low-impact activities over a long time. Something like carrying a heavy bag for hours can cause a strain.
What Are the Symptoms of a Trapezius Muscle Strain?
Some of the symptoms are:
- Muscle pain, especially after doing something that stretches or really contracts the muscle
- Pain that worsens when the muscle moves but improves with rest
- Swelling or discoloration
- Cramping or spasms
- Less muscle strength
- Loss of muscle function
- Popping sensation when you got injured
- Gap or dent in the normal outline of the muscle
How Is a Trapezius Muscle Strain Diagnosed?
Your doctor will probably be able to tell if you have a pulled trapezius muscle based on your symptoms, your medical history, and a physical exam. If you have a grade III strain, your doctor may be able to feel where the muscle has ripped completely apart. You may need an X-ray to rule out a fracture, dislocation, or another type of injury.
Pure muscle injuries can't be seen on an X-ray, though. In these cases, MRI may help, showing where the injury happened and if there was a complete rupture. An MRI may also show a collection of blood, called a hematoma, that can occur after an injury.
How Is a Trapezius Muscle Strain Treated?
Your doctor’s recommendations may depend on the grade of the injury.
Most minor strains respond well to the RICE treatment:
- R = Rest
- I = Ice
- C = Compression
- E = Elevation
For severe muscle strains, your doctor may refer you to an orthopedist. You may need to have the muscle surgically repaired or go through rehabilitation.
How Can You Prevent Trapezius Muscle Strains?
One of the best things you can do to lower your chances of getting an upper back strain is to work stretching into your daily routine. Stretching helps loosen your muscles so that they're less likely to freeze up.
Gently stretch in the morning when you get out of bed, before a workout, and before you lift something heavy.
Work stretching and strengthening exercises into your usual routine. Be careful when you extend your arms above your shoulders or lift heavy objects.
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